Op amps problem Gain Calculation

[newtype]

John Fields <jfields@austininstruments.com> wrote in
news:5hh0r1lom5d6e8h024i3ajo09r51da4mqp@4ax.com:

On 26 Dec 2005 17:58:43 GMT, newtype <fakeaddress@nowhere.net
wrote:
You need to see an anger management specialist.

---
Blow me.
---

Your know there's a good book written called "The Four Agreements"
Before you die of a heart attack, you should seriously read it.


.... snip...

I don't want to get off any hook. Someone wanted a ML4410
datasheet. I scanned the datasheet to a pdf and I posted it, in
multiple parts of rars & pars to a.b.s.e , since it was a pdf
binaray file. YOU Personally, must own a.b.s.e ? I posted
binary files to a binaries newsgroup, what newsgroup law did I
break? None.

---
No one has a quarrel with your posting files that were asked for
or, AFAIK, that they were RARs. You might have posted, if you
thought that anyone might have trouble with PARs, where they
could get the software they needed to decode them. What
everybody was bitching about was the _quantity_ of material
which you were posting which wasn't requested. That's been
stated over and over again. Why are you having so much trouble
understanding that?
---

Wrong. Everyone has a quarrel, even you. I got withing 3 days hate
emails. "Stop what you are doing immediately." "You dumb f%@king
bastard your ruining the newsgroup with your spam floods"
"I can't read what you are posting, my screen wont stop scrolling?"

well, finally a user with a returnable emial address, so I point
out, large files must be split up into smaller files, so news servers
can pass the data easily. Large data files get rejected. Try using
xnews, agent, gbabit, news xpress, all free.

I take a 10meg pdf file and make 10 1meg rar files and 3pars.
10 rar files is flooding the newsgroup? I highly doubt it.
Your mind is twisted.

And from the newsgroup the same person saying, my screen wont stop
scrooling. same message with a different public email?

What spam? This user sees alot of files. Unknown files.
"What the f#*k are these spammer!" Well they are rar files.
I'll use what ever archiving tool I want to. No one has a right
to tell me what archiving software to use, what operating sytem,
nothing.

Current users of a.b.s.e don't know what to do with rar and par
files, don't know how to use/configure newsreaders, accusing me
of posting files that look like they belong in a porn newsgroup,
music or video. Where's the problem here? humm, lack of
understanding, judgment ?

---
Not at all. I'm sure most of us know how to decode RARs, and a
flood or RARs and their associated PARs looks the same no matter
what newsgroup they're posted to. The comments about the porn
and video groups were probably because your flood made the
headers look the same on abse as they do there, if only becuse
of their volume. ---

10 small 1meg files, binary files that when uncoded is a datasheet
of an obsolete IC. 10 1meg files is not considered "VOLUME" by todays
internet traffic standards. The comments about the porn,
video & music, is because they have visited those sites. Why are
they there in those places? Your don't like a newsgroup, you
don't subscribe to it? It's 2 clicks to unsubscribe.
It's 2 clicks to kill a poster. "Roy L. Fuchs" , that's good.

There were like 5+ msgs saying to use someother newsreader.
Simple. Will that work. Nope. no one in a.b.s.e. is willing to use a
modern newsreader. Some email basher wants to know how to use
Outlook to read what I'm posting?

"I was told 'Go read the f*#king charter" . I did look for a
charter and a.b.s.e dosen't have a charter, never did.
I propose a newsgroup and I made a charter. And here you are
again attacking me, harassing me. I'm dead certain if there was
a company representatvie you'd be fired for harassment.

---
You need to get over being so thin-skinned if you want to play.

Especially when you consider that we (I, in any case) consider
harrassment to be what you've been doing with your unsolicited
posts after we've asked you to stop.

wrong. Not un-solicited. There was a request for a ML4410
datasheet and I posted it to an electronics newsgroup for
binaries, a.b.s.e . You object to posting binaries?

The newsgroup a.b.s.e. is a public forum for binaries, PDFs
executables, pictures. There is no charter, because it's self
explanitory "a.binaries.s.e" . History, a long time ago when a.b.s.e
was created. people started to u/l 100's of zip files , I mean 100's
of zip files of their programs. freeware, shareware, new pkarc, new
lharc, new zip, 100's of files of their programs they wrote. Along
came 100's of virus's too.

This is the meaning of 'floods'. the past 5 years saw the "flood"
of foreign porn pics, 1000's of porn files. There were posts
of 100's of zip files for a new cad program. This was all
before Web pages became popular. Who needs a newsgroup with all
the people complaining. Make a web page, no sweat. And there was much
rejoicing to the newsgroups, no more binary floods.
Back then no one knew about kill files, except the unix/linux users.

You don't know what flood means, as with other users in a.b.s.e
You see a bunch of files and that means it's porn. There have been
over 10 msgs to a.b.s.e from users, use another newsreader, agent,
xnews, etc. To no avail, the 3 monkeys attitude.

There is no charter for a.b.s.e I propose a new newsgroup with a
charter. A charter to support multi-part files for binaries.
You do not have to subscribe to a new newsgroup. No one is forcing
you. The internet/usenet is open to everybody.

So, it's PKB, plain and simple.

If you want to try to get me fired send an email to
elpresidente@austininstruments.com with your complaints and see
what happens. You might get lucky. But I'm about to retire
antway, so it won't make difference anyway.
---

No. Firing would be too easy. You need to see a psych doctor.
Visit, after visit, after visit. Nothing as sweet as torture.

You're a fucking idiot, and getting a newsgroup created won't
change that. Regardless of what you're looking for, we'll
give you what we want to, and if you don't like it, then take
a fucking hike.

From a professional, I would't expect less. Your kind always
badgers belittles everyone else.

It seems that f#*k is in your only vocabulary? Since you've been
following me around to specifics newsgroups, your like a stalker?
You accuse me of cross posting? In your news header, you have lined
up more than 10 newsgroups. I only have one! I visit every newsgroup
every so often.

You are the one that's doing all the cross postings.

Creating a new newsgroup to accept the 'flooding' as you call it,
Creating a charter that states multiple part files are allowed...
why am I a f@&king idiot for that ?

---
Because it's all unnecessary.
---

It is necessary and it's no big deal to create a new newsgroup. You
write one up, get a vote and present it. It's no big deal if You
subscribe to it or not, that is your choice, that is called freedom.
You, and others on a.b.s.e, don't know how to decode rars are
complaining, hell your stalking me around the internet.

Your complaning about the 'flood' of files! You have said it over
and over again, "Stop your dumg f*#k flood of files" .
It is necessary to understand the difference between posting
multi-part binary files to binaries newsgroup and flooding
a binaries newsgroup whit off topic binaries. You don't post
1000's of porn pics from europe, russia, asia.

You don't post 100's files pertaining to religion, poetry,
humanities. That is called flooding.

I wrote a charter for the new newsgroup. I clearly state for posting
multi-part binary files.

Beside someone else said there's alt.binaries.ebook.technical
That's where I'll be posting the datasheets I have.

---
Why? Does anyone really want them? Have you received requests
for them?
---

Beside being retirement age, your loosing your memory too?
I posted to a.b.s.e the 82s129 and there was one guy who said can I
repost rar 11 and 14. Is this not a request? I got a request for the
82s100. Iin your mind is this a request? Your still inflamed about
the flood issue. All of the files I posted to a.b.s.e were
pertinent to electronics, they were datasheets. they were multi-part
binary rars that when combined back together to make the pdf, was a
datasheet of obsolete TTL PROMs.

There is no need for a newsgroup such as you propose and,
consequently, there is no need for a call for votes.

If the current users of the newsgroup a.b.s.e , can't except
multiple part files, then I proposed a new newsgroup that will
carry multiple part files. Call it flooding?

There's no need for a new newsgroup now, as was pointed out
there's another newgroup being flooded as we speak. I swear I
looked thru 100's of binary newsgroups, just missed that one.
Must be 800+ newsgroups by now?

.... snip ...

As I said before,there was a request for a ML4410 datasheet and
I posted it to an electronics newsgroup for binaries, a.b.s.e .
You object to posting binaries? Nope, you object to me posting
because in the past 2 or 3 weeks, there were jpgs of a building
project in san francisco, a 'copyrighted' manual for a wavetek
175 that was 13megs,(a typical big pdf file), and other
'copyrighted' manual posts, which you have no problem with. I
don't recall anyone asking for these expilitly. But when I post
a jpg with 4 ECL ICs on a static, you attack me " ... You
F*%king idiot." .

---
I don't have any problems with any of the posts you mention
because they're typically one-time events or things most of us
who have been here for a while are interested in or would like
to see.

Wrong. The moment I posted the rar files, all you a-holes jumped all
over my case. You attaced me with spam email, attacked me in the
newsgroup. I put 5 of you in the kill file. Electronic datasheet pdf
spilt up into rars, so they can be propogated newsgroups servers.
And I reached requests from Arizona, England, Australia, Colorado.
No one has asked you for a datasheet.
I got asked, I posted the electronic datasheets to a newsgroup
created for binary files. This is where these files belong.
And you are telling me not to post files in a newsgroup created for
just reason, to post electronic data in binary form.

You dont have any right in telling anyone what to do.

For instance, the building in San Franscisco was a fortune
cookie factory that John Larkin, the owner of Highland
Technologies bought for two million dollars and is converting to
be his company's new facility.

2 million dollars!!! You are saying that it is perfectly fine for
someone who is rich to post pics & pdfs to a.b.s.e , but I can't
because I don't make that kind of money. No one asked JLarkin,
but you pester me over & over. You 'demand' who request those dumb
ass datasheets? I don't have to tell you anything. Your no body.
Your just a badgering piece of scum.


.... snip...

The rest of the stuff, like the Wavetek manual and whatever, gets
posted once, ostensibly because someone asked for it, and its
done with.

By your own words " who requested it". I'll answer... no one!
Was it a copyright Wavetek manual. YES. Wavetek could sue that guys
ass off. But you say the obsolete datasheets I post are coyrighted
material. Who is are you going to call if the company called end of
life to IC? The company dosen't exist. What I mean is there's no
company, the factory is part of parking mall, shopping center, part
of freeway. What is right and wrong here?

You have been carrying on a double standard.

I havn't reposted the full datasheet have I. NO. It's in your mind,
You have decided to "own" alt.binaries.schematics.electronics
It is a god given right for you to protect a.b.s.e from everyone. You
are not a moderator, you are not a net cop. Your a nobody but a
paying customer to a ISP. The internet was created to be an open door
to the world. You have decided it is your duty to slam shut the doors
of freedom posting, where on-topic correct posting is due. You are a
vilganty.

You, on the other hand are a stranger here with no points and
the first thing you do is start posting hundreds of megabytes of
stuff that NO ONE wants to see and when you're asked to quit you
get all defensive and post even more.
---

I was asked for any early prom info. I posted the signetics 1975
datasheet, I got 2 request from the newsgroup for a 82s129 and
82s100.

The internet was created to open the doors to strangers, to break
down barriers. You don't control the internet, You don't control any
newsgroup, your not a moderator. Your no body. I don't need any
points to subscribe, join, a newsgroup. Nobody needs priviliges to
join a newsgroup.

100's of megs? I can't fathom... I can't count 100's of megs.
I can count 100's of 1meg files, that when made back into the PDFs,
makes up less than 40megs across 5 datasheets.

---
Fine. like I said before, I don't think anyone got upset
because you posted stuff that was asked for, what the problem
was was that when you were asked to stop posting stuff no one
had asked for, not only did you not stop, you posted more just
to rub our noses in it. ---

I don't remember anyone asking you explictly for ML4410, 82s129,
82s100 datasheets. It's hard to mind your own business at your
age huh?

---
Not at all. I'm a member of this newsgroup and have been for a
long time, so if some newbie asshole like you comes along and
starts upsetting people I've grown to like over time, my
friends, then it _is_ my business. What does age have to do
with it? ---

I'l ask you again, DID anyone ask you explictly for ML4410, 82s129,
82s100 datasheets. ans. NO. I demand you tell me who has asked you
for a datasheet? ans: _____ ? clueless.

You are not part of any controlling overseeing governing group of a
newsgroup. You are not a net god from alt.config or any governing
newsgroup panel overseer.

You have no basis of complaining on what I have posted. All you have
is your own personal gains. As pointed out above, Only the rich
people who make 2,000,000.00 dollars can post without being harassed,
spammed. Only member with points can post binaries? What newsgroup
points!!! There never has been a point system, a rating system?
In your twisted old feeble head, you made up this point system.

Moderated too, huh? LOL, _You're_ the one who needs to get
lost.

I've volunteered as a moderator back in school, I know the
hours, it's not impossible. Just some robot software progams ?
What's the big deal?

---
The _want_ to be a moderator. Go check out
misc.business.product-dev; you might find a soul mate there.
---

Wrong. read 'FAQs and Posting Guidelines for news.groups.reviews'
Summary: This posting describes how to write a review for
news.groups.reviews and answers some questions on the moderation of
that group.

Your just attacking and harassing me. I can only wonder
if your the one who's been send me spam email?

---
Hey, you're supposed to be the one with the internet skills and
the fake email address, so go find out.
Lemme know what you find, OK?

I find that you are a self proclaimed newsgroup controller with no
credentials to be so. Your living in the past century, don't know the
worldly internet is changing. The $100.00 portable is already on the
plate and billions of people are going to be connected to the
internet.

I don't want to be a moderator, but if it means starting a new
newsgroup, it's worth it since i've done it before and you havn't. To
filter out non-related topics to a new newsgroup is well worth it. A
new newsgroup will have very little traffic at 1st. I can always
request the new newsgroup be un-moderated. It's no big deal.

 

[newtype]

Let me ask you a simple question, besides all the blah blah blah.
Have you seen any further psots from me in
Alt.Binaries.Schematics.electronics ?
Just a simple yes or no ?

ans : ___

 

[John Fields]

On 28 Dec 2005 00:48:30 GMT, newtype <fakeaddress@nowhere.net>
wrote:

Let me ask you a simple question, besides all the blah blah blah.
Have you seen any further psots from me in
Alt.Binaries.Schematics.electronics ?
Just a simple yes or no ?

ans : ___

---
What's a 'psot'?

--
John Fields
Professional Circuit Designer

 

[Don Kelly]

I am a bit concerned about the distance and angle between source and pickup.
What are you using as a source? Can you shroud the pickup so that less
ambient light hits it? However, about all you can do now is to test it- then
make modifications.

--

Don Kelly @shawcross.ca
remove the X to answer
----------------------------
"fritz" <nofritzb@noisland.net> wrote in message
news:5oWdnWlF04Ee-S7eRVn-vQ@wavecable.com...

Don Kelly wrote:
---
How much space do you have? This can limit options. The machines that I
used a photocell on were 5HP units and space, away from couplings, wasn't
a problem. There a negative of a picture of a circle with black and
white sectors and about 6 inch diameter worked well. the light source and
photocell were mounted in a U bracket over the film which was put between
two sheets of 2mm plexiglass. Alignment as needed for a reflected signal
wasn't critical as one was picking up the direct beam through clear areas
on the film. It was necessary to amplify the output signal but the
technology has advanced since then (early 80's) so better light
output/sensing may not need the amplifier. It is no big deal to add one.
The magnetic approach may still work but may need some shielding. Tin
can around all but the pickup side. Even a shaft bump and a capacitive
pickup can work.

Mr. Kelly,
I figured that a picture is worth a thousand words so I put up some
photos and layout here:

http://ballistic.org/wood/router.htm

Check it out.
Thanks.

f.

 

[John Fields]

On Fri, 30 Dec 2005 01:55:26 GMT, "Simon" <a@b.c2zj> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:j2u4r1pek3rsmq47du7d4v288dlgv98c1t@4ax.com...
On 28 Dec 2005 00:48:30 GMT, newtype <fakeaddress@nowhere.net
wrote:

Let me ask you a simple question, besides all the blah blah blah.
Have you seen any further psots from me in
Alt.Binaries.Schematics.electronics ?
Just a simple yes or no ?

ans : ___

---
What's a 'psot'?

Whats pedantric?

---
There's no such word as 'pedantric', and you missed the apostrophe
in 'what's'.


--
John Fields
Professional Circuit Designer

 

[John Fields]

On Fri, 30 Dec 2005 11:42:10 GMT, "Simon" <a@b.c2zj> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:th6ar1l80bvcjdkippjthfhvt7fchrf8oh@4ax.com...
On Fri, 30 Dec 2005 01:55:26 GMT, "Simon" <a@b.c2zj> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:j2u4r1pek3rsmq47du7d4v288dlgv98c1t@4ax.com...
On 28 Dec 2005 00:48:30 GMT, newtype <fakeaddress@nowhere.net
wrote:

Let me ask you a simple question, besides all the blah blah blah.
Have you seen any further psots from me in
Alt.Binaries.Schematics.electronics ?
Just a simple yes or no ?

ans : ___

---
What's a 'psot'?

Whats pedantric?

---
There's no such word as 'pedantric', and you missed the apostrophe
in 'what's'.

wow another spelling flame.

---
Hardly. I merely pointed out your two errors. You made another one
too, just above. Since 'wow' was the first word in the sentence, it
should have been capitulized.
---

You really are a sad little fuck. are you bald
50 inch waist and have constant sweat patches under your arms?

---
None of the above.

BTW, you Should have capitalized 'are', previous, since it's the
first word in a sentence, and what you probably meant to write was:
"Are you bald and do you have a 50 inch waist and constant sweat
patches under your arms?"

See how much better the sentence flows? Gives it a nice rhythm,
don't you think?
---

Get a f'ing life for god's sake.

---
I _have_ a life, and not a repressed one, like yours, where you're
afraid to spell out "fucking".
---

COuld you not understand the OP's question even with
his spelling mistake?

---
Of course.
---

If not you are really thick.

---
But since it's not, "if not", I'm not.
---

If you could, why did you deflect from the question with a dig as his spelling mistake?

---
In order to get the answer for yourself you need to go back and read
the whole thread. Then the answer should be obvious. If it isn't,
come back and ask me about what you don't understand and I'll try to
explain it to you with words of less than three syllables so that
you'll have a chance to get it.
---

awaits deflection from these 2 questions

---
Wait away, I don't owe you a thing.

--
John Fields
Professional Circuit Designer

 

[fritz]

Don Kelly wrote:

I am a bit concerned about the distance and angle between source and pickup.
What are you using as a source? Can you shroud the pickup so that less
ambient light hits it? However, about all you can do now is to test it- then
make modifications.

The source I figured would be the smallest halogen 12v bulb inserted

inside an Aluminium 1/4" tube with the bulb at the base of the tube and
the light exiting about 3/4" later. This would shield the pickup from
the light near it. Then the photocell would also be inserted into a tube
and positioned deep within it so that this would add to the light
shielding. This would effectivley shield the photo cell from the lamp as
well as most ambient light.
As you say, all I can do is build it and test it. Several years ago
I bought a computer addon digital storage oscope (PCS64i) which I
haven't tried out but it should give me a good look at the photocell out.
Thanks for all the suggestions. It's up to me now to find the
appropriate photocell, figure a power supply and check the setup.

f.

 

[Jasen Betts]

the motor is probablly too fast for a photo-resistive cell (like CdS cells)
a photo-transistor or photo-diode is probably the way to go. use shielded
cable. it's more important that the photo-sensor only see the shaft than
that the light only shine on the shaft, if there's ambient light shining on
the shaft what harm can it do?


23,000 rmp is a little less than 400pulses/ps. Is that too fast? I
thought that I would do a trial with the LED and one of the radio shack
generics hooked up to the little scope. See what I get. After the new
year....

I read a cycle time (response time + decay time) of 50ms in a catalogue (I
had no luck locating a datasheet) that basically means 20Hz, or 600RPM is
the where the signal strength starts dropping in ideal conditions. (this was
for an ORP12-ish LDR they also had a lower resistance one with worse
performance)

photo diodes and photo transistors work up to much higher rates, (remote
control applications at 40Khz aren't even close to the limit) 400Hz would be
no problem.



--

Bye.
Jasen

 

[PeteS]

stonefoz wrote:

i know the lithium batterys pop if overcharged but all the plans i've seen
have curr/temp/volt/time feedback loops and emergancy trips on them. what
is the minimal setup if i trickle charge and don't care how long it takes?
are they realy that sensitive?

As mentioned above, Li+ battery chargers deal with all sorts of issues.
They also incorporate a safety timer, but that's a last resort.

The Li+ charge cycle is quite simple.

If within valid temperature range (usually 0C to +40C to start
charging), drive a constant current until V(cell) = 4.2V. Now drive a
constant voltage (at 4.2V) until the charge current drops to some
predetermined cutoff (C/20 or so). Stop charging.

Do not trickle charge a Li+ battery that is already charged without
checking the terminal voltage and cutting out.

Why do you want to know? Are you trying to design a Li+ charger into
something or just rigging one up for your own use? Chargers are cheap.

Cheers

PeteS

 

[Jasen Betts]

On 2006-01-04, Craig S. <cspurlocktakethisout@takethisoutmtneer.net> wrote:

I purchased a Belkin Tunecast II FM modulator and have been less than
thrilled with its performance in a vehicle. I have an XM SkyFi2 with a
built-in modulator that provides an excellent signal, so surely there must
be something better out there than the Belkin.

Is there a website that does Consumer Reports style side by side performance
reviews on electronics and audio products?

Or does anyone have any exceptionally positive experience with other
portable FM transmitters?

the silicon chip magazine kitset ones were pretty good. back in the 80s they
were a solution looking for a problem... I expect the 2001 vewrsion is good
too.

Bye.
Jasen

 

[DanK]

"PeteS" <ps@fleetwoodmobile.com> wrote in message
news:1136456911.324489.297180@g14g2000cwa.googlegroups.com...

DanK wrote:
Hopefully some nice DDR guru is out there...

My DDR design is for a single REGISTERED DDR modules (64 bits wide plus
ECC/parity bits). The module was acting like cas latency was 2.5 when I
had
set it to 2, so I changed my design to work with CL=2.5 and continued
with
the de-bug. Now I'm pretty sure the module thinks the burst length is
set
to 4, even though I set it to 2. (a 128 bit write to address 0/1 also
gets
written into address 2/3). I've gone over the initialization and I
can't
find anything wrong. Anybody got any ideas?

Thanks

Dan

You don't say whether you are using someone else's DDR controller or
are making your own.

There are many adjustable parameters in a typical DDR controller (and
in the DDR device - there are two accessible registers - status and
extended status).

Apart from the multiple writes, what other issues (faults) do you see?

Cheers

PeteS

Its my own controller in an fpga and it definatly thinks burst length = 4 as
I see a double DSQ pulse on a read. A 1GB modue works correctly, the 2 GB
module does not (both work in a server motherboard so I know the ddr is
good). Other than the multiple writes everything seems to work.

 

[lee]

Analog or Digital

Analog: use a 555 (or two) and selectable RC time constants.

Digitally: use a counter, (or counters), a slow clock, and a DAC

If you really want to get fancy use a micro; a bit of over kill.

 

[Alexander]

"lee" <drennie@cfl.rr.com> schreef in bericht
news:3zcwf.4893$gf7.276@tornado.tampabay.rr.com...

Analog or Digital

Analog: use a 555 (or two) and selectable RC time constants.

Digitally: use a counter, (or counters), a slow clock, and a DAC

If you really want to get fancy use a micro; a bit of over kill.



You're using both ways (digitally and analog) PWM.

Perhaps you should look into that also.

 

On Mon, 09 Jan 2006 16:59:15 -0500, Jono <jono@dont-spam-me.com>
wrote:

What kind of relay would I need? Sorry but I know only very very basic
electronics.


Sure, with the proper relay, no sweat. I did it with a window mounted
A/C. The A/C on-board thermostat sucked, so I got a cheap house unit,
built a relay box, and voila, great A/C control. I has set it to cool.
With the heater, set it to heat. Mount the thermostat within the
insulated box.

Al

The relay has two ratings coil voltage and contact amperage/voltage.
The coil voltage has to be compatible with your control circuit
(thermostat side). The contact rating has to switch the current of
the heater (or higher) at some given voltage rating.

At minimum you need a single pole single throw relay normally open
(that is, it will call for heat when the coil is energized). Many
thermostats are designed to run on 24 Volts AC (coil voltage your
relay would need to be, along with a transformer to power it)

The 24 VAC coil rating is used in the states because it doesn't
require heavy wire with a 600 volt insulation rating the way
electrical code does. There will usually be a small 10 Volt-Ampere,
24 VAC transformer located on the heater, as a rule, to step down the
voltage for the control circuit (thermostat).

A 24VAC mechanical thermostat probably wouldn't survive switching
120/240 VAC for very long (if at all). A 24 VAC electronic thermostat
would die instantly with 120 or 240 on it.

There are heating thermostats that will run on 120/240 directly and
would need no relay (just wire the contacts in series with the heater)
You can find them in hardware stores for baseboard electric heating.
They are rather primitive, and use a bimetallic switch and don't
usually allow one to adjust the hysteresis ("dead band" differential
between turning on and then turning off again - a degree or two as a
rule - otherwise the thermostat tends to turn on and off frequently
and that kills the contacts)

Some low voltage thermostats (but not all) will allow one to adjust
the hysteresis.

If you need tight control use a solid state relay. They switch as the
voltage of the ac crosses zero and don't have contacts that will die
the way an electromechanical relay will - you can set the hysteresis
to zero - turns off and on at the same temperature (or damn close)

An electrician could tell you what you need to do . . . if that's too
confusing.

For good tight control a "proportioning" controller is used. It
switches on and off regularly (like every 5-30 seconds) and just stays
on longer to bring the temperature up. They tend to cost more, and
the contacts won't last forever if asked to switch a heavy current.

Some folks call them "proportional" controllers, but a true
proportional control modulates the power by switching like a lamp
dimmer or varying the voltage from 0-100%.
--

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

 

[Henry]

"Paul Aspinall" <paul@aspy.co.uk> wrote in message
news:Jnzvf.85748$PD2.82424@fe1.news.blueyonder.co.uk...

Hi
I have an application which I want to use 'dimmable' lights.....

I have the light components, but the actual dimmer has a 10 volt reference
voltage, ie.
0volts = 100% light
10volts = 0% light

I know I can add a pot, so I can regulate the voltage. However, I would
like
to have a device which will change this voltage for me, over time (ie.
going
from 0 to 10v over 1 minute, 1 hour, etc etc), so that I can vary the
light,
and how quickly it dims.

Does anyone know how this can be done??

Thanks

After dabbling again with some electronics (after about 20 years), I have
rediscovered just how versatile these littel 555 (556 for dual package) are.
I am certain that I have seen a light fader circuit somewhere. I think it
took two 555s (single 556).

Henry

 

[JeffM]

I need some expert advice
BrianS

http://groups.google.com/group/sci.electronics.basics/browse_frm/thread/7b7c0624331012bb/3958f18673b5f374?q=EVERY-group-*-*-*-*-*-*-*-*-appear+*-proper-answer-*-*-*-given+much-easier-*-*-*-*-what's-going-on+*-frowned-on+*-correcting+*-polite-*-mention-*-*-*-*-*-*-*+Just-because-*-*-*-*-*-*-*-*-does-not-mean-*-*-*-*-*-*+*-Followup-To-*+*-*-*-too-lazy-*-*-*-*-*-appropriate-*+*-*-_perfect_-*-*-*-*+*-*-*-*-two-groups-*-*-aren't-*-different

 

[JeffM]

Sorry for the cross post,
Jono

Your understanding of the term is severly lacking.

(What you did was WORSE.)
http://groups.google.com/group/sci.electronics.basics/browse_frm/thread/7b7c0624331012bb/3958f18673b5f374?q=EVERY-group-*-*-*-*-*-*-*-*-appear+*-proper-answer-*-*-*-given+much-easier-*-*-*-*-what's-going-on+*-frowned-on+*-correcting+*-polite-*-mention-*-*-*-*-*-*-*+Just-because-*-*-*-*-*-*-*-*-does-not-mean-*-*-*-*-*-*+*-Followup-To-*+*-*-*-too-lazy-*-*-*-*-*-appropriate-*+*-*-_perfect_-*-*-*-*+*-*-*-*-two-groups-*-*-aren't-*-different
..
..

Would it be possible to connect a home thermostat
to a small portable electric heater?

::I know only very very basic electronics.

This isn't even electronics. It's Electricity 101.

Until you know how to get similar things working with small batteries,
it's best to leave these things to a pro
--or at least someone with some experience.
At the VERY least, before applying power,
have it checked out by someone knowledgeable.

Starting out with lethal voltages is not a way to learn.
The possibility of a house fire is yet another issue.

 

[Henry]

"Jasen Betts" <jasen@free.net.nospam.nz> wrote in message
news:42c1.43c4c007.1e038@clunker.homenet...

On 2006-01-10, Henry <henrytj@pghmail.com> wrote:
Thanks everyone for all the answers to my previous questions. My photo
circuit is mostly done. Done in the fact that it works. It could
probably
use much improvement, but it works. I built it on a bread board and
mounted
it in a hard plastic VHS tape case. (Had to use a razor blade to cut off
the
inside ring for the video tape.) Those actually make reasonably nice
project
cases, and the transluscent ones even allow one to easily see indicator
LEDs
without having to drill holes for them. But I worry that they kind of
plastic that the transluscent ones are made from may be static prone.
Anyone
know?

probably they are. you could line them with antistatic plastc (ask at any
place that assembles computers they'll have heaps.)

Bye.
Jasen

Atually I previously asked at 3 different places (like CompUSA, etc.) for
anti-static foam or plastic and was told that they have none. Some said they
throw it away immediately, some said that it goes with the customer.

Henry

 

[Henry]

"Alexander" <electricdummy@hotmail.com> wrote in message
news:dq3al2$p01$1@news3.zwoll1.ov.home.nl...

"Henry" <henrytj@pghmail.com> schreef in bericht
news:LqqdnRyQTfFLX1neRVn-tQ@pghconnect.com...
Okay, now that I have dabbled and put some circuits together with some
25+
year old parts (7400 series TTL). What might I do if I were to be doing
this
with newer, more up to date, technology? Are there programmable
controllers
on a chip that are easy to work with. Keep in mind I am looking for
things
that I can do with under $50 in parts, like with the TTL gates. Is there
a
relatively easy way to interface simple logic gates/transistors with a
PC,
laptop, PDA, etc?

Thanks,
Henry


Try Microcontrollers or FPGA's
both are cheap to very expensive and easy to program with the right
software.
For some you must build a programmer or buy an "expensive" one.

For simpeler things you might consider GAL's or PAL's.

Alexander

On Wikipedia
http://en.wikipedia.org/wiki/Microcontroller
"...For almost every bare microcontroller manufacturer, there are a dozen
little companies repacking them into a more hobbyist friendly package..."

So, can someone recommend a particularly good/inexpensive hobby/student
friendly manufacturer or supplier?

Thanks,
Henry

 

[Jasen Betts]

On 2006-01-11, Henry <henrytj@pghmail.com> wrote:

Okay, now that I have dabbled and put some circuits together with some 25+
year old parts (7400 series TTL). What might I do if I were to be doing this
with newer, more up to date, technology? Are there programmable controllers
on a chip that are easy to work with.

the basic stamp has that reputatioon, it's as bit more pricy than
the atmel AVR and microchip PIC series. both of which can also be
programmed with minimal hardware...

Keep in mind I am looking for things
that I can do with under $50 in parts, like with the TTL gates. Is there a
relatively easy way to interface simple logic gates/transistors with a PC,
laptop, PDA, etc?

all of these devices can be connected directly to parallel ports
or with a little extra stuff to a serial port.

some have USB interfaces too.

Bye.
Jasen