Simple circuit to flash an LED from RF...

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

[...]

I vaguely recall an ancient bipolar transistor low leakage thyristor
functional equivalent that could be used to flash an LED brightly but
very slowly depending on charging of a low leakage reservoir capacitor.

It snapped into conduction when the voltage reached about 4v.

It was briefly in vogue for flashing them in the early red LED era just
prior to UJTs becoming common and cheap.
Click to expand...

I vaguely recall the same thing. I tried to reconstruct it, but only got
one snap and then it hung. I searched through analogspiceman\'s files and
couldn\'t find anything. But it\'s out there somewhere. Here\'s my offering:

Version 4
SHEET 1 1608 1700
WIRE 352 -304 304 -304
WIRE 464 -304 432 -304
WIRE 512 -304 464 -304
WIRE 608 -304 512 -304
WIRE 304 -288 304 -304
WIRE 608 -272 608 -304
WIRE 464 -240 464 -304
WIRE 304 -192 304 -208
WIRE 608 -192 608 -208
WIRE 400 -112 400 -192
WIRE 464 -64 464 -144
WIRE 400 0 400 -16
FLAG 304 -192 0
FLAG 400 0 0
FLAG 608 -192 0
FLAG 512 -304 Q2E
SYMBOL voltage 304 -304 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL npn 464 -112 M0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL pnp 400 -144 M180
WINDOW 0 43 35 Left 2
WINDOW 3 39 62 Left 2
SYMATTR InstName Q2
SYMATTR Value 2N3906
SYMBOL res 448 -320 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL cap 592 -272 R0
SYMATTR InstName C1
SYMATTR Value 1uf
TEXT 376 -424 Left 2 ;\'2N3904/06 SCR
TEXT 376 -392 Left 2 !.tran 0 10m 0
TEXT 576 -392 Left 2 !.options plotwinsize=0




--
MRM
 
On 8/2/2022 7:36 AM, Ricky wrote:
On Sunday, July 31, 2022 at 8:54:55 PM UTC-4, amdx wrote:
On 7/31/2022 2:58 PM, jla...@highlandsniptechnology.com wrote:
On Sun, 31 Jul 2022 10:56:27 -0500, amdx <am...@knology.net> wrote:

I\'d like to setup a high Q LC to receive a local Radio station probably
charging a cap, when the charge is high enough flash an LED.
Maybe set the trigger point of an SCR, or could just a zener do it. I
don\'t have LT spice, so please don\'t post and answer with that.

Thanks, Mikek
I expect that a strong radio station could light an LED visibly
continuously, given a good well-matched antenna. Or charge a cap and
use a discharge circuit to get bright blinks.

Here\'s my high-voltage low current blinker:

https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0

But LT Spice is free, easy to learn, and a wonderful tool for stuff
like this.

I was hoping to do it with just a coil and cap. I have some 6\" coils with
Q over 1000. Very high impedance a resonance, so might need a lower
impedance pickup coil.
Their Litz wire, so I don\'t want to tap them.
A high-Q circuit is going to be useless in this application, because you need to draw power which will spoil the Q of any high-Q circuit. The only use of a high-Q circuit would be for tuning, but with the power you are drawing off, it won\'t be high-Q anymore, just a tuned circuit.
Click to expand...
Someone can LT spice that and compare a 1200 Q LC to a 200 Q LC.
Show I\'m
 right!    Or wrong.

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
On Tuesday, August 2, 2022 at 1:05:00 PM UTC-4, amdx wrote:
On 8/2/2022 7:36 AM, Ricky wrote:
On Sunday, July 31, 2022 at 8:54:55 PM UTC-4, amdx wrote:
On 7/31/2022 2:58 PM, jla...@highlandsniptechnology.com wrote:
On Sun, 31 Jul 2022 10:56:27 -0500, amdx <am...@knology.net> wrote:

I\'d like to setup a high Q LC to receive a local Radio station probably
charging a cap, when the charge is high enough flash an LED.
Maybe set the trigger point of an SCR, or could just a zener do it. I
don\'t have LT spice, so please don\'t post and answer with that.

Thanks, Mikek
I expect that a strong radio station could light an LED visibly
continuously, given a good well-matched antenna. Or charge a cap and
use a discharge circuit to get bright blinks.

Here\'s my high-voltage low current blinker:

https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0

But LT Spice is free, easy to learn, and a wonderful tool for stuff
like this.

I was hoping to do it with just a coil and cap. I have some 6\" coils with
Q over 1000. Very high impedance a resonance, so might need a lower
impedance pickup coil.
Their Litz wire, so I don\'t want to tap them.
A high-Q circuit is going to be useless in this application, because you need to draw power which will spoil the Q of any high-Q circuit. The only use of a high-Q circuit would be for tuning, but with the power you are drawing off, it won\'t be high-Q anymore, just a tuned circuit.


Someone can LT spice that and compare a 1200 Q LC to a 200 Q LC.
Show I\'m
right! Or wrong.
Click to expand...

You might try LTspice with this file. It seems to contain descriptions for all the parts. So you won\'t have to learn how to incorporate models which can be a clumsy part of the job.

I seem to recall, the basic parts like L and C will include a tiny bit of R by default because the simulations can go wonky when the Q is infinite. So you will need to adjust those parasitic values to set your Q. I expect you know how to do that.


--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209
 
On 08/01/2022 03:11 AM, amdx wrote:
Ya, I had it for a while played with it had fun with it, I did some circuits, went out and got subcircuits, all was cool and as I recall I was
trying to show how match was important to power transfer nothing major just maximum power transfer, I posted it here
got a shit load of flack, was told I need to learn electronics before I try LT spice. I just said Fuck it. Haven\'t touched it since.
Mikek
Click to expand...
The thing when posting to usenset is that you should never ever read any of the replies.
 
On 8/3/2022 4:42 AM, Johann Klammer wrote:
On 08/01/2022 03:11 AM, amdx wrote:
Ya, I had it for a while played with it had fun with it, I did some circuits, went out and got subcircuits, all was cool and as I recall I was
trying to show how match was important to power transfer nothing major just maximum power transfer, I posted it here
got a shit load of flack, was told I need to learn electronics before I try LT spice. I just said Fuck it. Haven\'t touched it since.
Mikek


The thing when posting to usenset is that you should never ever read any of the replies.
Yep, but still I read this.
Click to expand...

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
On Wed, 03 Aug 2022 11:42:45 +0200, Johann Klammer
<klammerj@NOSPAM.a1.net> wrote:

On 08/01/2022 03:11 AM, amdx wrote:
Ya, I had it for a while played with it had fun with it, I did some circuits, went out and got subcircuits, all was cool and as I recall I was
trying to show how match was important to power transfer nothing major just maximum power transfer, I posted it here
got a shit load of flack, was told I need to learn electronics before I try LT spice. I just said Fuck it. Haven\'t touched it since.
Mikek


The thing when posting to usenset is that you should never ever read any of the replies.
Click to expand...

Like the famous Signetics WOM ic, the write-only memory.

100% production yield.

Of course, you won\'t see this.
 
John Larkin wrote:
On Wed, 03 Aug 2022 11:42:45 +0200, Johann Klammer
klammerj@NOSPAM.a1.net> wrote:

On 08/01/2022 03:11 AM, amdx wrote:
Ya, I had it for a while played with it had fun with it, I did some circuits, went out and got subcircuits, all was cool and as I recall I was
trying to show how match was important to power transfer nothing major just maximum power transfer, I posted it here
got a shit load of flack, was told I need to learn electronics before I try LT spice. I just said Fuck it. Haven\'t touched it since.
Mikek


The thing when posting to usenset is that you should never ever read any of the replies.

Like the famous Signetics WOM ic, the write-only memory.

100% production yield.

Of course, you won\'t see this.
Click to expand...

The plot of \"pins remaining vs. socket insertions\" is a classic in itself.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
Phil Hobbs wrote:
John Larkin wrote:
On Wed, 03 Aug 2022 11:42:45 +0200, Johann Klammer
klammerj@NOSPAM.a1.net> wrote:

On 08/01/2022 03:11 AM, amdx wrote:
Ya, I had it for a while played with it had fun with it, I did some
circuits, went out and got subcircuits, all was cool and as I recall
I was
trying to show how match was important to power transfer nothing
major just maximum power transfer, I posted it here
got a shit load of flack, was told I need to learn electronics
before I try LT spice. I just said Fuck it. Haven\'t touched it since.
Mikek


The thing when posting to usenset is that you should never ever read
any of the replies.

Like the famous Signetics WOM ic, the write-only memory.

100% production yield.

Of course, you won\'t see this.


The plot of \"pins remaining vs. socket insertions\" is a classic in itself.
Click to expand...

I put it at
<https://electrooptical.net/www/sed/Signetics25120WriteOnlyMemory_WOM_.pdf>
for anyone who hasn\'t seen it.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top