Op amps problem Gain Calculation

[Peter Hucker]

On Wed, 02 May 2007 00:27:01 +0100, Coyoteboy <coyoteboyuk@hotmail.com> wrote:

Peter Hucker proclaimed to alt.electronics ...

Legitimate people put out weird caller IDs. I got a phonecall from Dell
tech support about my faulty motherboard,m and the number began with +*
I also got a phonecall saying "international" from a BT Openworld helpdesk
- he'd called the wrong number, and there was a slight argument, I
recorded the last part on the answering machine:

You've been abusing people again eh

Foulmouthed telephone solicitors deserve it

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

Always finish what you have starte

 

[Charles]

Advertising, are we?

 

[Jim]

I just need the rubber drive bands (2 per deck) mine are so old they slip. Thanks.
If I should post this some where else let me know, maybe alt.history or Antiques? J/K

 

[Charles]

"Jim" <Jim@NoMail.com> wrote in message
news:wWhii.190471$dC2.125054@newsfe13.lga...

I just need the rubber drive bands (2 per deck) mine are so old they slip.
Thanks.
If I should post this some where else let me know, maybe alt.history or
Antiques? J/K

sci.electronics.repair

 

[John Fields]

On Tue, 03 Jul 2007 01:49:16 GMT, Jim <Jim@NoMail.com> wrote:

I just need the rubber drive bands (2 per deck) mine are so old they slip. Thanks.
If I should post this some where else let me know, maybe alt.history or Antiques? J/K

---
http://servicesales.sel.sony.com/ecom/accessories/web/productSearch.do


--
JF

 

[Richard]

Aly wrote:

Hello,

Ideas please?

A small professional UV box with two 8W tubes will cost about Ł100, and is,
professionally made and neat and tidy. I'm wondering if for sake of ease it
would be easier to just go out and buy one?

I've seen the UV "fly killer," tubes on eBay for say Ł10, which are
mentioned in a few of the tutorials online. Ballasts I have at home
somewhere. Would need a neat little case, cut glass, switches, bits bobs,
and time.

This is all purely for making the odd PCB so nothing commercial. There's
also those little UV nail boxes for curing the plastic, they're only about
Ł20 although I wonder about even coverage with those, and if indeed it is
the right type of UV?

Circular tubes? U-shaped tubes? Straight tubes? Little 9W dual parallel
tubes?

I'm just wondering in the end if it would be easier to just buy one,
although that's not really in keeping with the spirit of diy.

Many thanks for any input, I'm just looking for ideas and opinons really.
I'd also be half tempted to put in regular tubes too so that it can be used
as a light box.

Friendly regards,

Alison

ps. There's this one at Rapid for Ł110 in a little kit;

http://www.rapidonline.com/searchresults.aspx?style=0&kw=34-0690

Only seen the thread today and don't have the patience to read all the
contributions so apologies if this has been said elsewhere:

I built a UV box using a desk drawer as the case - approx 1' x 1'. I
painted the inside gloss white, screwed the ballasts and spring clips to
the interior and fixed 3 UV B tubes into the spring clips. When
exposing a coated PCB I simply put the PCB on my desk, sandwiched the
artwork onto it with a sheet of perspex and then placed the lightbox on
top and left it cooking for the required time.

Total cost was whatever the price of the tubes was. It was very cheap
and only slightly nasty. I still have it (somewhere) but it never
failed to produce adequate results.

HTH

Richard

Richard

 

[Richard]

Leon wrote:

Elektor mag. had a design a few months ago.

Leon

Wow!

I have crates of back issues of Elektor from when I subscribed in the
80's - I didn't know it was still in print. Thanks!

Richard

 

[Joy]

On Tue, 31 Jul 2007 17:42:22 -0400, JeffM <jeffm_@email.com> wrote:

Joy wrote:
Does anyone know where I could buy a cheap DTMF tone generator?
I think that's what they are called. They used to be used to enter
touch tone phone sounds into the receivers of dial pay phones
so you could access your answering machine.
[ . . . ]
Thanks for any leads or even the right search keywords on ebay.
I didn't find any with my searches.

I believe you're over-thinking this:
http://www.google.com/search?q=dialer+hold-it-up-to

And sorry if these aren't appropriate newsgroups.

It is kinda a misc.consumers question.

Ok. I'm not sure how I'm over-thinking this... I appreciate ideas and
comments.
I didn't see anything on your google search although the keyword 'dialer'
was very helpful.

Thank you!

 

[Coyoteboy]

Richard wrote:

Aly wrote:

Hello,

Ideas please?

A small professional UV box with two 8W tubes will cost about Ł100,
and is,
professionally made and neat and tidy. I'm wondering if for sake of
ease it
would be easier to just go out and buy one?

I've seen the UV "fly killer," tubes on eBay for say Ł10, which are
mentioned in a few of the tutorials online. Ballasts I have at home
somewhere. Would need a neat little case, cut glass, switches, bits
bobs,
and time.

This is all purely for making the odd PCB so nothing commercial. There's
also those little UV nail boxes for curing the plastic, they're only
about
Ł20 although I wonder about even coverage with those, and if indeed it is
the right type of UV?

Circular tubes? U-shaped tubes? Straight tubes? Little 9W dual
parallel
tubes?

I'm just wondering in the end if it would be easier to just buy one,
although that's not really in keeping with the spirit of diy.

Many thanks for any input, I'm just looking for ideas and opinons really.
I'd also be half tempted to put in regular tubes too so that it can be
used
as a light box.

Friendly regards,

Alison

ps. There's this one at Rapid for Ł110 in a little kit;

http://www.rapidonline.com/searchresults.aspx?style=0&kw=34-0690




Only seen the thread today and don't have the patience to read all the
contributions so apologies if this has been said elsewhere:

I built a UV box using a desk drawer as the case - approx 1' x 1'. I
painted the inside gloss white, screwed the ballasts and spring clips to
the interior and fixed 3 UV B tubes into the spring clips. When
exposing a coated PCB I simply put the PCB on my desk, sandwiched the
artwork onto it with a sheet of perspex and then placed the lightbox on
top and left it cooking for the required time.

Total cost was whatever the price of the tubes was. It was very cheap
and only slightly nasty. I still have it (somewhere) but it never
failed to produce adequate results.

HTH

Richard

Richard

Thought I'd drag this up again having found the likes of this on ebay:
http://tinyurl.com/2qxgyk

I'm getting tired of etching with acids etc - I have a spare scanner
body (inc glass) sitting around and lots of acetate I can print onto.
Are this sort of bulb the correct wavelength for etching?

 

[Baron]

Coyoteboy said:

I'm getting tired of etching with acids etc - I have a spare scanner
body (inc glass) sitting around and lots of acetate I can print onto.
Are this sort of bulb the correct wavelength for etching?

I have a couple of these, USB scanners a well and would also like to
know about this. It could be a very cheap way to create a lightbox.

Thanks:
--
Best Regards:
Baron.

 

[Brad]

Hi Peter,

Please get a cup of coffee and read my post again. Where did
I say my control is "dead"?

The dehumidifier, which has a mechanical control, is "dead".

Brad


On Sat, 13 Oct 2007 10:48:49 -0400, in alt.electronics you wrote:

On Sat, 13 Oct 2007 13:01:45 GMT, bpetria@verizon.net (Brad) wrote:

Hi,

Does anyone know if there is a dehumidifier, instead of using
a humidistat setting, allows you to set the time on and the time off?

Example: Set the dehumidifier to run for a half hour, then be off
for an hour. This cycle repeats over and over.

Almost all new dehumidifiers have electronic controls.

My mechanical control dehumidifier recently "died". I used an external
controller I made that employs a binary counter. The dehumidifier, which was
set to "Max", was plugged into this external device. When the power was off,
in effect it is the same as "unplugging" the dehumidifier. I used this
system for years and it worked GREAT. Note: I use a humidity gauge.

PROBLEM:

With electronic control dehumidifiers, "unplugging" (in effect) the
dehumidifier for a half hour or more, most likely will cause it to loose the
settings.
Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active keystroke logger (spyware) in your PC.



Ok, so your control is dead. Bypass it, get a cheap-o timer from the
hardwar store and be done with it... Right?

As to the electronic units loosing settings, I won't comment, but that
implies each power failure would require you reset your de-humidifier:
really dumb design.

 

[PeterD]

On Thu, 18 Oct 2007 12:08:22 GMT, bpetria@verizon.net (Brad) wrote:

Hi Peter,

Please get a cup of coffee and read my post again. Where did
I say my control is "dead"?

The dehumidifier, which has a mechanical control, is "dead".

Brad

As in:

My mechanical control dehumidifier recently "died".

With the way that people now write the English, it could be
interperted most any way one wants. Ok, so the whole thing is dead...
I'll accept that!

 

[John Fields]

On Thu, 18 Oct 2007 08:19:56 -0400, PeterD <peter2@hipson.net>
wrote:

With the way that people now write the English, it could be
interperted most any way one wants. Ok, so the whole thing is dead...
I'll accept that!

---
"the English"?


--
JF

 

[Ohmster]

Dexter H.<dexterhussain223@yahoo.com> wrote in
news:4711854a$0$15265$88260bb3@unlimited.teranews.com:

Watch NFL Games Online!
For every one who wants to watch the games online because they dont
live in the teams town or are at work i found a site that has
basically every game covered. Its perfect if you have afford a monthly
$70 direct tv nfl access subscription. they got a bunch of channels
The sites http://inflationline.wizzerhoe.com

Okay fuck all of that $70 bullshit. Get back to me when you find a crack
for this and we can watch all of the games for free. Until then, shut up
and get lost.


--
~Ohmster | ohmster /a/t/ ohmster dot com
Put "messageforohmster" in message body
(That is Message Body, not Subject!)
to pass my spam filter.

 

[John Fields]

On Sun, 28 Oct 2007 21:36:24 -0500, Ohmster <root@dev.nul.invalid>
wrote:

Dexter H.<dexterhussain223@yahoo.com> wrote in
news:4711854a$0$15265$88260bb3@unlimited.teranews.com:

Watch NFL Games Online!
For every one who wants to watch the games online because they dont
live in the teams town or are at work i found a site that has
basically every game covered. Its perfect if you have afford a monthly
$70 direct tv nfl access subscription. they got a bunch of channels
The sites http://inflationline.wizzerhoe.com

Okay fuck all of that $70 bullshit. Get back to me when you find a crack
for this and we can watch all of the games for free. Until then, shut up
and get lost.

---
Hey, asshole, what in the hell does that have to do with
electronics?

Or have you forgotten that you were dishing out a ration of shit on
abse for someone else doing the same thing?

Fucking hypocritical thief, you are.


--
JF

 

[John Fields]

On Sun, 27 Jan 2008 01:46:52 -0800 (PST), lou <Lou717@gmail.com>
wrote:

Hi!
Would appreciate some help.

Was thinking of using a car radio at home. Specs read current
consumption 1.5A (at .5W).

---
Something's wrong there.

Power is equal to the product of voltage and current, so:


P = IE = 12V * 1.5A = 18 watts


or, for 0.5W:

P 0.5W
I = --- = ------ ~ 0.042A
E 12V

---

The fuse is 5A.

DC power supply should be at least 1.5A but can I go up to 4A without
harming the radio?

---
Yes; the radio will only draw the current it needs.
---

Not sure if I would gain any improvement in sound.

---
As long as the power supply looks like a voltage source the quality
of the sound won't suffer.
---


--
JF

 

[PeterD]

On Sun, 27 Jan 2008 09:52:04 -0600, John Fields
<jfields@austininstruments.com> wrote:

On Sun, 27 Jan 2008 01:46:52 -0800 (PST), lou <Lou717@gmail.com
wrote:

Hi!
Would appreciate some help.

Was thinking of using a car radio at home. Specs read current
consumption 1.5A (at .5W).

---
Something's wrong there.

Power is equal to the product of voltage and current, so:


P = IE = 12V * 1.5A = 18 watts


or, for 0.5W:

P 0.5W
I = --- = ------ ~ 0.042A
E 12V

I think the OP's specificatins rate current at .5W of audio output...
<g>

---

The fuse is 5A.

DC power supply should be at least 1.5A but can I go up to 4A without
harming the radio?

---
Yes; the radio will only draw the current it needs.

Assuming the power supply is regulated and doesn't allow the voltage
to rise significantly as current drops.

---

Not sure if I would gain any improvement in sound.

---
As long as the power supply looks like a voltage source the quality
of the sound won't suffer.
---

Assuming the power supply is regulated and doesn't allow the voltage
to change significantly as audio levels change.