Design help / ideas current sensor...

B

bitrex

Guest
On 1/5/22 1:01 AM, Jan Panteltje wrote:
On a sunny day (Tue, 4 Jan 2022 14:43:59 -0800 (PST)) it happened Phil Allison
pallison49@gmail.com> wrote in
66ad22c9-e1fb-44de-8bec-630abd8d155bn@googlegroups.com>:

mkr5000 wrote:
=============

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the
output of an amateur radio xmtr when it\'s on the air.


** For what purpose ??

Any any practical design, the actual purpose is * everything *.
Why omit it from your post?

Most ham transmitters have a mike with a push button
Hang an optocoupler or relay on that contact and be done with it
It is just babble talk he does?

Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.
 
J

Jan Panteltje

Guest
On a sunny day (Wed, 5 Jan 2022 01:50:59 -0500) it happened bitrex
<user@example.net> wrote in <ndbBJ.74583$cW6.56727@fx08.iad>:

On 1/5/22 1:01 AM, Jan Panteltje wrote:
On a sunny day (Tue, 4 Jan 2022 14:43:59 -0800 (PST)) it happened Phil Allison
pallison49@gmail.com> wrote in
66ad22c9-e1fb-44de-8bec-630abd8d155bn@googlegroups.com>:

mkr5000 wrote:
=============

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the
output of an amateur radio xmtr when it\'s on the air.


** For what purpose ??

Any any practical design, the actual purpose is * everything *.
Why omit it from your post?

Most ham transmitters have a mike with a push button
Hang an optocoupler or relay on that contact and be done with it
It is just babble talk he does?


Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.

Yea, whats-it-called Darwin Awards.
To add to the not so simple solutions I once made an AC current meter using an
old audio tapehead:
http://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
opamp... gives mains AC current.
mains wire glued in front of the headgap.
 
P

Phil Allison

Guest
Jan Panteltje wrote:
================
Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.

** See: https://en.wikipedia.org/wiki/Therac-25

Yea, whats-it-called Darwin Awards.
To add to the not so simple solutions I once made an AC current meter using an
old audio tapehead:
http://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
opamp... gives mains AC current.
mains wire glued in front of the headgap.

** If you just added a second tape head - a few inches from the first -
you could tell which way the electrons were moving.



..... Phil
 
J

Jan Panteltje

Guest
On a sunny day (Wed, 5 Jan 2022 00:26:06 -0800 (PST)) it happened Phil Allison
<pallison49@gmail.com> wrote in
<284bfe45-5deb-41f2-a7f7-383c5774fa14n@googlegroups.com>:

Jan Panteltje wrote:
===============

Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.

** See: https://en.wikipedia.org/wiki/Therac-25


Yea, whats-it-called Darwin Awards.
To add to the not so simple solutions I once made an AC current meter using an
old audio tapehead:
http://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
opamp... gives mains AC current.
mains wire glued in front of the headgap.


** If you just added a second tape head - a few inches from the first -
you could tell which way the electrons were moving.

Interesting, but those move fast, 300,000 km / second
so in 1 mS 300 km, 1 ms is still 1000 Hz within audio range
so say 100us = 10kHz = 30 kMm distance would do.
Also it is not the same electron that comes out,
those are more like dominos falling over, in the mean time they
do a loop the loop around the copper atoms and occasionaly pass on momentum
to the electrons in the next atom, that is why speed of electrickety
is somewhat slower in a conductor.
Somebody will correct this I am sure ;-)
 
J

Jim Jackson

Guest
On 2022-01-05, Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
On a sunny day (Wed, 5 Jan 2022 00:26:06 -0800 (PST)) it happened Phil Allison
pallison49@gmail.com> wrote in
284bfe45-5deb-41f2-a7f7-383c5774fa14n@googlegroups.com>:

Jan Panteltje wrote:
===============

Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.

** See: https://en.wikipedia.org/wiki/Therac-25


Yea, whats-it-called Darwin Awards.
To add to the not so simple solutions I once made an AC current meter using an
old audio tapehead:
http://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
opamp... gives mains AC current.
mains wire glued in front of the headgap.


** If you just added a second tape head - a few inches from the first -
you could tell which way the electrons were moving.

Interesting, but those move fast, 300,000 km / second
so in 1 mS 300 km, 1 ms is still 1000 Hz within audio range
so say 100us = 10kHz = 30 kMm distance would do.

No the electrons do not travel at the speed of light. Common fallacy.

see e.g. https://www.sciencefocus.com/science/how-fast-does-electricity-flow/

Also it is not the same electron that comes out,
those are more like dominos falling over, in the mean time they
do a loop the loop around the copper atoms and occasionaly pass on momentum
to the electrons in the next atom, that is why speed of electrickety
is somewhat slower in a conductor.
Somebody will correct this I am sure ;-)
 
J

Joe Gwinn

Guest
On Tue, 4 Jan 2022 17:36:03 +0000, Piglet <erichpwagner@hotmail.com>
wrote:

On 04/01/2022 17:06, mkr5000 wrote:
On Tuesday, January 4, 2022 at 12:04:39 PM UTC-5, mkr5000 wrote:
On Tuesday, January 4, 2022 at 11:44:14 AM UTC-5, erichp...@hotmail.com wrote:
On 04/01/2022 3:44 pm, mkr5000 wrote:
I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS
Couple things occur to me:

If the mode is constant envelope (like RTTY or FM) then the current draw
or RF output will be kinda constant during the over, if SSB or CW then
the detectable signal will fluctuate with modulation.

12V 100W is 8.3 amps, assuming 100% efficiency but I reckon most rigs
are 50% or so which means the RX idle current of <2A should be very easy
to distinguish from 15 amps TX. Does your power supply have an ammeter
display, many do and it can be instructive?

Reed contacts can be used to sense cable current (and much smaller than
what you are considering) but hysteresis effect is very large and having
closed on TX current may not release if the RX current is not vastly lower.

Sensing voltage drop in the power cable is possible, sketch attached
shows one way that has been used. (LM301 is great at sensing right up to
positive rail, uA741 less so but usable. Or reconfigure to use later
parts sensing in the negative return). Use ohms law and knowledge of the
power cable wiring gauge to determine how far apart the sense pickoff
taps should be, I reckon 5 milli-ohms resistance may be enough?


https://www.dropbox.com/s/c7kqeqkaxux75lz/current_sense_rig.pdf?raw=1

piglet
Great !
At least I know I\'m on the right track. I like starting with the reed switch idea and if I have to work up from there. The switch would have dry contacts and be passive which is pretty cool. Inductance has never been one of my strong points so what is a good place to start for a coil. Thing is, I really need something that is completely passive and works on the AC field alone.
I don\'t want to do anything \"in circuit\".


No problem. Look for reed switches with a long body - so you can wind
enough turns of wire onto it - and with lower Ampere-Turns values (fewer
turns of wire will be needed to activate).

No real inductance involved here, just wind from 1 to 20 turns (wild
guess range) of wire around the reed.

Some gottchas to beware of: the reeds could react fast enough to buzz at
100/120Hz, the power supply input current could be so spiky even at low
load that getting reliable discrimination needs experimental fine
tuning, reed contacts love to weld themselves so do not shunt with a
capacitor (unless via a series resistor) and use well within ratings.

Yes, they do tend to stick or even weld. If I recall, one traditional
remedy was to use rhodium or iridium plating on the contact tips, and
no gold.

And then there are mercury-wetted contacts, but Mercury is bad these
days, probably because it worked so well.

Burglar alarm door switches used to have such plating.

Joe Gwinn
 
M

mkr5000

Guest
On Wednesday, January 5, 2022 at 4:23:49 AM UTC-5, Tauno Voipio wrote:
On 5.1.22 2.08, mkr5000 wrote:
On Tuesday, January 4, 2022 at 6:51:51 PM UTC-5, bitrex wrote:
On 1/4/22 10:44 AM, mkr5000 wrote:
I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either..

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output).. Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc.. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore).. Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS

Asking for a \"relay contact\" seems to imply OP wants a binary OK/over
current detection, there\'s a simple over-current detect for a DC bus on
Jim Thompson\'s legacy site:

https://electrooptical.net/static/oldsite/www.analog-innovations.com/SED/CurrentSense.pdf

It looks straightforward enough to adapt to higher voltages and currents
and also optically isolate if that\'s what\'s desired.

well I guess I could have stated it this way --
output of an amateur radio xmtr to KNOW when it\'s on the air.
how bout that as a purpose?

or is it? ....hmm
All the transmitters I have seen under my 60 years as a licensed ham
have an output for the PTT/Transmit mode signal. It is usually targeted
for controlling an external power amplifier.

Why on earth cannot it be used? It is aeons easier to use the proper
control signal than to synthetize something like it. The synthesized
signal comes too late to be correct, by definition.

--

-TV
Tauno --
I see a PTT connector but it\'s an input that\'s meant for externally putting the xcvr in transmit mode. Don\'t see any sort of output that would mimic the PTT switch on the mic. There is also a din connector but from what I gather it\'s for data.

And this is a Yaesu model.
 
S

server

Guest
On Tue, 4 Jan 2022 07:44:21 -0800 (PST), mkr5000 <mikerbgr@gmail.com>
wrote:

I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS

You could put a tee connector in the RF cable and tap off a few
milliwatts into a diode detector and an SSR.

Maybe use one of the little Pomona boxes with a connector on each
side. Gimmick cap pickoff.





--

I yam what I yam - Popeye
 
M

mkr5000

Guest
On Wednesday, January 5, 2022 at 12:12:50 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Tue, 4 Jan 2022 07:44:21 -0800 (PST), mkr5000 <mike...@gmail.com
wrote:

I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS
You could put a tee connector in the RF cable and tap off a few
milliwatts into a diode detector and an SSR.

Maybe use one of the little Pomona boxes with a connector on each
side. Gimmick cap pickoff.





--
I yam what I yam - Popeye
jesus -- I didn\'t think of that ! and that\'s embarrassing. sometimes it\'s right ion front of your face.
I hate it when that happens. yeah man -- you got it.

I would want something that\'s totally isolated from affecting the xcvr performance.
A cap in series ? then the diode?
Really all I need to do is grab a few millivolts or better yet, enough to power a sensitve optocoupler and still be self powered.
(I\'m not much of a designer anymore -- just breadboard till it works) :)
 
J

Jan Panteltje

Guest
On a sunny day (Wed, 5 Jan 2022 16:25:37 -0000 (UTC)) it happened Jim Jackson
<jj@franjam.org.uk> wrote in <slrnstbhk1.53u.jj@iridium.wf32df>:

On 2022-01-05, Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
On a sunny day (Wed, 5 Jan 2022 00:26:06 -0800 (PST)) it happened Phil Allison
pallison49@gmail.com> wrote in
284bfe45-5deb-41f2-a7f7-383c5774fa14n@googlegroups.com>:

Jan Panteltje wrote:
===============

Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.

** See: https://en.wikipedia.org/wiki/Therac-25


Yea, whats-it-called Darwin Awards.
To add to the not so simple solutions I once made an AC current meter using an
old audio tapehead:
http://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
opamp... gives mains AC current.
mains wire glued in front of the headgap.


** If you just added a second tape head - a few inches from the first -
you could tell which way the electrons were moving.

Interesting, but those move fast, 300,000 km / second
so in 1 mS 300 km, 1 ms is still 1000 Hz within audio range
so say 100us = 10kHz = 30 kMm distance would do.

No the electrons do not travel at the speed of light. Common fallacy.

see e.g. https://www.sciencefocus.com/science/how-fast-does-electricity-flow/

Also it is not the same electron that comes out,
those are more like dominos falling over, in the mean time they
do a loop the loop around the copper atoms and occasionaly pass on momentum
to the electrons in the next atom, that is why speed of electrickety
is somewhat slower in a conductor.
Somebody will correct this I am sure ;-)

Thanks
so about 1 mm / second
 
M

mkr5000

Guest
On Wednesday, January 5, 2022 at 12:45:49 PM UTC-5, Jan Panteltje wrote:
On a sunny day (Wed, 5 Jan 2022 16:25:37 -0000 (UTC)) it happened Jim Jackson
j...@franjam.org.uk> wrote in <slrnstbh...@iridium.wf32df>:
On 2022-01-05, Jan Panteltje <pNaonSt...@yahoo.com> wrote:
On a sunny day (Wed, 5 Jan 2022 00:26:06 -0800 (PST)) it happened Phil Allison
palli...@gmail.com> wrote in
284bfe45-5deb-41f2...@googlegroups.com>:

Jan Panteltje wrote:
===============

Sounds great if it\'s for something like triggering a babble-timer or a
fancy neon \"ON AIR\" sign to impress the fam. God help him if it\'s for
something related to the safety of himself or others. It is unfortunate
he didn\'t specify cuz maybe he run off to build a THERAC 25 from ham
radio parts.

** See: https://en.wikipedia.org/wiki/Therac-25


Yea, whats-it-called Darwin Awards.
To add to the not so simple solutions I once made an AC current meter using an
old audio tapehead:
http://panteltje.com/pub/play_back_head_current_sensor_img_1153.jpg
opamp... gives mains AC current.
mains wire glued in front of the headgap.


** If you just added a second tape head - a few inches from the first -
you could tell which way the electrons were moving.

Interesting, but those move fast, 300,000 km / second
so in 1 mS 300 km, 1 ms is still 1000 Hz within audio range
so say 100us = 10kHz = 30 kMm distance would do.

No the electrons do not travel at the speed of light. Common fallacy.

see e.g. https://www.sciencefocus.com/science/how-fast-does-electricity-flow/

Also it is not the same electron that comes out,
those are more like dominos falling over, in the mean time they
do a loop the loop around the copper atoms and occasionaly pass on momentum
to the electrons in the next atom, that is why speed of electrickety
is somewhat slower in a conductor.
Somebody will correct this I am sure ;-)
Thanks
so about 1 mm / second
originally thought about doing something inline but didn\'t think of a tee connector -- using a box with so239 etc was too much hassle
 
S

server

Guest
On Wed, 5 Jan 2022 09:41:36 -0800 (PST), mkr5000 <mikerbgr@gmail.com>
wrote:

On Wednesday, January 5, 2022 at 12:12:50 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Tue, 4 Jan 2022 07:44:21 -0800 (PST), mkr5000 <mike...@gmail.com
wrote:

I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS
You could put a tee connector in the RF cable and tap off a few
milliwatts into a diode detector and an SSR.

Maybe use one of the little Pomona boxes with a connector on each
side. Gimmick cap pickoff.





--
I yam what I yam - Popeye
jesus -- I didn\'t think of that ! and that\'s embarrassing. sometimes it\'s right ion front of your face.
I hate it when that happens. yeah man -- you got it.

I would want something that\'s totally isolated from affecting the xcvr performance.
A cap in series ? then the diode?
Really all I need to do is grab a few millivolts or better yet, enough to power a sensitve optocoupler and still be self powered.
(I\'m not much of a designer anymore -- just breadboard till it works) :)

Something like this should work. The gimmick is the cap.

https://www.dropbox.com/s/f99752dqosa3frb/RF_Det_Gimmick.jpg?raw=1

Twist the gimmick until it works. It shouldn\'t affect the receive
signal.

Or use the RF to light a neon and put that near a photoresistor. Or
just look at the neon.

Directly driving an LED or SSR with RF might work, but some have a lot
of capacitance.

What\'s this for?




--

I yam what I yam - Popeye
 
B

bitrex

Guest
On 1/5/2022 1:03 PM, mkr5000 wrote:
On Wednesday, January 5, 2022 at 12:56:27 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Wed, 5 Jan 2022 09:41:36 -0800 (PST), mkr5000 <mike...@gmail.com
wrote:

On Wednesday, January 5, 2022 at 12:12:50 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Tue, 4 Jan 2022 07:44:21 -0800 (PST), mkr5000 <mike...@gmail.com
wrote:

I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS
You could put a tee connector in the RF cable and tap off a few
milliwatts into a diode detector and an SSR.

Maybe use one of the little Pomona boxes with a connector on each
side. Gimmick cap pickoff.





--
I yam what I yam - Popeye
jesus -- I didn\'t think of that ! and that\'s embarrassing. sometimes it\'s right ion front of your face.
I hate it when that happens. yeah man -- you got it.

I would want something that\'s totally isolated from affecting the xcvr performance.
A cap in series ? then the diode?
Really all I need to do is grab a few millivolts or better yet, enough to power a sensitve optocoupler and still be self powered.
(I\'m not much of a designer anymore -- just breadboard till it works) :)
Something like this should work. The gimmick is the cap.

https://www.dropbox.com/s/f99752dqosa3frb/RF_Det_Gimmick.jpg?raw=1

Twist the gimmick until it works. It shouldn\'t affect the receive
signal.

Or use the RF to light a neon and put that near a photoresistor. Or
just look at the neon.

Directly driving an LED or SSR with RF might work, but some have a lot
of capacitance.

What\'s this for?
--

I yam what I yam - Popeye
something that won\'t sell. like everything else I\'ve done. :)
one thing that\'s nice about optoisolators I\'ve used, is that it\'s amazing the range of voltage that will trigger them with just on resistor. I put a 1k on one I have and the npn output would react to everything from 3v to
20 or so if I remember right without drawing to much led current.

For higher powers or where safety is the concern it would be good to
have two sensors; the primary indirect input current sensor detects
non-activity, and the secondary RF sensor detects activity. It\'s simpler
to build a fail-safe non-activity detector than it is to build a
fail-safe activity detector - negligible input current is a pretty
reliable indicator of non-activity. Then the state of negligible input
current detected by the primary sensor actively holds the \"SAFE\" lamp or
such on.

Power to the transmitter turns it off and then the RF detector confirms
output activity. If the sensor or indicator for \"SAFE\" fails then it
defaults to the (potentially) unsafe condition. And any incongruity in
the states should also defaults to \"unsafe.\"

But please refer any design of real-world health or safety critical
systems to a qualified engineering professional, though, I\'m definitely
not entirely confident that\'s as bug-free as it can be either even with
an ideal implementation.
 
T

Tauno Voipio

Guest
On 5.1.22 19.00, mkr5000 wrote:
On Wednesday, January 5, 2022 at 4:23:49 AM UTC-5, Tauno Voipio wrote:
On 5.1.22 2.08, mkr5000 wrote:
On Tuesday, January 4, 2022 at 6:51:51 PM UTC-5, bitrex wrote:
On 1/4/22 10:44 AM, mkr5000 wrote:
I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS

Asking for a \"relay contact\" seems to imply OP wants a binary OK/over
current detection, there\'s a simple over-current detect for a DC bus on
Jim Thompson\'s legacy site:

https://electrooptical.net/static/oldsite/www.analog-innovations.com/SED/CurrentSense.pdf

It looks straightforward enough to adapt to higher voltages and currents
and also optically isolate if that\'s what\'s desired.

well I guess I could have stated it this way --
output of an amateur radio xmtr to KNOW when it\'s on the air.
how bout that as a purpose?

or is it? ....hmm
All the transmitters I have seen under my 60 years as a licensed ham
have an output for the PTT/Transmit mode signal. It is usually targeted
for controlling an external power amplifier.

Why on earth cannot it be used? It is aeons easier to use the proper
control signal than to synthetize something like it. The synthesized
signal comes too late to be correct, by definition.

--

-TV
Tauno --
I see a PTT connector but it\'s an input that\'s meant for externally putting the xcvr in transmit mode. Don\'t see any sort of output that would mimic the PTT switch on the mic. There is also a din connector but from what I gather it\'s for data.

And this is a Yaesu model.

Which Yaesu model?

Do you have its manual? Have a look of recommended linear
amplifier connection. The T/R signal should be there.

--

-TV
 
M

mkr5000

Guest
On Wednesday, January 5, 2022 at 2:37:01 PM UTC-5, Tauno Voipio wrote:
On 5.1.22 19.00, mkr5000 wrote:
On Wednesday, January 5, 2022 at 4:23:49 AM UTC-5, Tauno Voipio wrote:
On 5.1.22 2.08, mkr5000 wrote:
On Tuesday, January 4, 2022 at 6:51:51 PM UTC-5, bitrex wrote:
On 1/4/22 10:44 AM, mkr5000 wrote:
I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS

Asking for a \"relay contact\" seems to imply OP wants a binary OK/over
current detection, there\'s a simple over-current detect for a DC bus on
Jim Thompson\'s legacy site:

https://electrooptical.net/static/oldsite/www.analog-innovations.com/SED/CurrentSense.pdf

It looks straightforward enough to adapt to higher voltages and currents
and also optically isolate if that\'s what\'s desired.

well I guess I could have stated it this way --
output of an amateur radio xmtr to KNOW when it\'s on the air.
how bout that as a purpose?

or is it? ....hmm
All the transmitters I have seen under my 60 years as a licensed ham
have an output for the PTT/Transmit mode signal. It is usually targeted
for controlling an external power amplifier.

Why on earth cannot it be used? It is aeons easier to use the proper
control signal than to synthetize something like it. The synthesized
signal comes too late to be correct, by definition.

--

-TV
Tauno --
I see a PTT connector but it\'s an input that\'s meant for externally putting the xcvr in transmit mode. Don\'t see any sort of output that would mimic the PTT switch on the mic. There is also a din connector but from what I gather it\'s for data.

And this is a Yaesu model.
Which Yaesu model?

Do you have its manual? Have a look of recommended linear
amplifier connection. The T/R signal should be there.

--

-TV
It\'s an FT-840 but I want to do something universal if I can.
Thanks sincerely for all the help. Many ideas to try.
 
J

John Larkin

Guest
On Wed, 5 Jan 2022 10:03:43 -0800 (PST), mkr5000 <mikerbgr@gmail.com>
wrote:

On Wednesday, January 5, 2022 at 12:56:27 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Wed, 5 Jan 2022 09:41:36 -0800 (PST), mkr5000 <mike...@gmail.com
wrote:

On Wednesday, January 5, 2022 at 12:12:50 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Tue, 4 Jan 2022 07:44:21 -0800 (PST), mkr5000 <mike...@gmail.com
wrote:

I\'m going to just come right out and ask for some assistance on this. There are still \"areas\" in electronics I have never had any experience \"tinkering\" with in all my years as an \"advanced\" hobbyist. You guys are walking encyclopedias on so much. This is something I\'ve never messed with --

I\'ve been wanting to somehow get a relay contact or a simple opto npn output to react to the output of an amateur radio xmtr when it\'s on the air. Simple enough and would be easy to get in there and look for the PTT contacts and diy something but I don\'t want to do that. Most (if not all) of these xcvrs don\'t have a self contained relay to perform the function either.

So --
My immediate first thought was to sense the RF with a FSM and I may still breadboard something but I\'m guessing as well shielded most of these new radios are, it\'s the actual antenna rf that would probably be the best source and I had better be pretty darn close to it. (100 watts or so output). Plan on experimenting with it -- don\'t have the parts yet.

But then it also occured to me that I may be able to make something that would just sense the current being drawn from the power supply and have looked into some of these split coil sensors etc (and asc712?). After all, in receive mode current draw from the supply would be next to nothing and transmit for 100 watts would go up to .83 amps or so. Pat myself on the back anyway for the creative thinking I guess :) But -- like I say, I
have never toyed with these sensors or instrumentation amplifiers etc. I see some off the shelf split coil ones (or maybe something diy?) and it looks like an AD623 is a good choice for amplifying millivolt signals? Anyway -- I just wondered what advice or ideas you guys may have and if it\'s possible, what the simplest lowest parts count approach would be?

Another thing I though of this morning and another thing I never messed with much are magnetic reed switches. I kinda doubt this can be
done but wonder if they make them sensitive enough to somehow react to that current draw from the supply with the right type of coil. By the way, the power supply of course has the AC mains wire but also the DC output on another cable. (Most ham xcvrs don\'t have their own power supply anymore). Long post I know but hopefully can get some input. Maybe .83 amps is too negligible?

THANKS
You could put a tee connector in the RF cable and tap off a few
milliwatts into a diode detector and an SSR.

Maybe use one of the little Pomona boxes with a connector on each
side. Gimmick cap pickoff.





--
I yam what I yam - Popeye
jesus -- I didn\'t think of that ! and that\'s embarrassing. sometimes it\'s right ion front of your face.
I hate it when that happens. yeah man -- you got it.

I would want something that\'s totally isolated from affecting the xcvr performance.
A cap in series ? then the diode?
Really all I need to do is grab a few millivolts or better yet, enough to power a sensitve optocoupler and still be self powered.
(I\'m not much of a designer anymore -- just breadboard till it works) :)
Something like this should work. The gimmick is the cap.

https://www.dropbox.com/s/f99752dqosa3frb/RF_Det_Gimmick.jpg?raw=1

Twist the gimmick until it works. It shouldn\'t affect the receive
signal.

Or use the RF to light a neon and put that near a photoresistor. Or
just look at the neon.

Directly driving an LED or SSR with RF might work, but some have a lot
of capacitance.

What\'s this for?
--

I yam what I yam - Popeye
something that won\'t sell. like everything else I\'ve done. :)
one thing that\'s nice about optoisolators I\'ve used, is that it\'s amazing the range of voltage that will trigger them with just on resistor. I put a 1k on one I have and the npn output would react to everything from 3v to
20 or so if I remember right without drawing to much led current.

There\'s no reason to help people who won\'t answer simple questions.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon
 
A

Anthony William Sloman

Guest
On Thursday, January 6, 2022 at 7:16:48 AM UTC+11, John Larkin wrote:
On Wed, 5 Jan 2022 10:03:43 -0800 (PST), mkr5000 <mike...@gmail.com> wrote:
On Wednesday, January 5, 2022 at 12:56:27 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Wed, 5 Jan 2022 09:41:36 -0800 (PST), mkr5000 <mike...@gmail.com> wrote:
On Wednesday, January 5, 2022 at 12:12:50 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Tue, 4 Jan 2022 07:44:21 -0800 (PST), mkr5000 <mike...@gmail.com> wrote:

<snip>

one thing that\'s nice about optoisolators I\'ve used, is that it\'s amazing the range of voltage that will trigger them with just on resistor. I put a 1k on one I have and the npn output would react to everything from 3v to 20 or so if I remember right without drawing to much led current.

There\'s no reason to help people who won\'t answer simple questions.

John Larkin doesn\'t pose simple questions, doesn\'t understand the answers he gets to his ill-posed questions, and gets snippy about it.

--
Bill Sloman, Sydney
 
P

Phil Allison

Guest
IEEE Bill rabid nutter bill....@ieee.org wrote:
===========================================
On Thursday, January 6, 2022 at 7:16:48 AM UTC+11, John Larkin wrote:

There\'s no reason to help people who won\'t answer simple questions.
John Larkin doesn\'t pose simple questions,

** JL did this time, same one I posed and the \"mkr5000\" troll will not reply.

Most poster\'s projects are stupid, dangerous or illegal.
Some are all three.
Others are simply fake.
Like IEEE Bill.



...... Phil
 
A

Anthony William Sloman

Guest
On Thursday, January 6, 2022 at 12:57:02 PM UTC+11, palli...@gmail.com wrote:
IEEE Bill rabid nutter bill....@ieee.org wrote:
==========================================> > On Thursday, January 6, 2022 at 7:16:48 AM UTC+11, John Larkin wrote:

There\'s no reason to help people who won\'t answer simple questions.
John Larkin doesn\'t pose simple questions,

** JL did this time, same one I posed and the \"mkr5000\" troll will not reply.

\"What\'s this for\" isn\'t a simple question. Sometimes there is a simple answer, but mostly the poster needs to supply a lot of context to provide a useful response, and neither you nor John Larkin is great at seeing problems from the original poster\'s point of view, or in fact any except your own.

Most poster\'s projects are stupid, dangerous or illegal.
Some are all three.
Others are simply fake.

Like IEEE Bill.

I do know why Phil thinks that. It makes him feel better. He hasn\'t any rational basis for that bit of abuse (or most of the stuff he posts) but he does feel the need to project his numerous psychological problems onto other people. So we all have to be autistic as well as fake.

--
Bill Sloman, Sydney
 
E

Edward Hernandez

Guest
The John Doe troll stated the following in message-id
<sdhn7c$pkp$4@dont-email.me>:

> The troll doesn\'t even know how to format a USENET post...

And the John Doe troll stated the following in message-id
<sg3kr7$qt5$1@dont-email.me>:

The reason Bozo cannot figure out how to get Google to keep from
breaking its lines in inappropriate places is because Bozo is
CLUELESS...

NOBODY likes the John Doe troll\'s contentless spam.

And yet, the clueless John Doe troll has continued to post incorrectly
formatted USENET articles that are devoid of content (latest example on
Thu, 6 Jan 2022 03:32:20 -0000 (UTC) in message-id
<sr5ns4$etm$1@dont-email.me>).

This posting is a public service announcement for any google groups
readers who happen by to point out that the John Doe troll does not even
follow the rules it uses to troll other posters.

DEcDsyku2ILF
 

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