Re: Looking for a Low Cost On Delay Timer

["Guv Bob" <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx>]

"Jim" <alarminex@xxxxxxx> wrote in message =
news:a5a7b349-3c13-4ef2-a8a1-7bc7d501230a@xxxxxxxxxxxxxxxxxxx
On Thursday, August 29, 2013 1:17:30 PM UTC-4, Guv Bob wrote:
> "Guv Bob" <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote in message =
news:ft6dnaIbSdpI-YPPnZ2dnUVZ_vednZ2d@xxxxxxxxxxxxxxxx "unruh" =
<unruh@xxxxxxxxxx> wrote in message =
news:WxsTt.233047$Z84.231177@xxxxxxxxxxx > On 2013-08-28, Guv Bob =
<guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > "unruh" =
<unruh@xxxxxxxxxx> wrote in message =
news:lAHSt.180556$po1.28313@xxxxxxxxxxx > >> On 2013-08-26, Guv Bob =
<guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote: > >> > "Guv Bob" =
<guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote in message =
news:1_udnQ7rBpNjRo7PnZ2dnUVZ_sidnZ2d@xxxxxxxxxxxxxxxx > >> > Names can =
be confusing, so here's what I'm doing.... > >> >> > >> >> =
http://img43.imageshack.us/img43/7434/wvm.gif > >> >> > >> >> When 12VDC =
is applied to the input, I need a 12VDC output for 5 seconds. Then =
output will go back off and stay off until the input goes to zero. Then =
cycle starts again. > >> >> > >> >> Current for both legs is in the =
10-50ma range. > >> >> > >> >> A simple on-delay timer would work but =
I'm having trouble finding one with NC contacts. Tons of stuff $100+, =
but for this application, it has to be under $20. > >> >> > >> =
>>=3D=3D=3D > >> > > >> > Thanks for all the tips and good info. I had =
wanted to put something together from components but my brain is too far =
behind these days. I'm going to give this a shot and hopefully I'm not =
picking the wrong one. It's $5 at Frys... > >> > > >> > Velleman MK111 > =
>> > =
http://www.vellemanusa.com/downloads/0/minikits/manuals/manual_mk111.pdf =
> >> > >> Except that looks like an oscillator rather than a "oneshot" > =
>> You said that you wanted something that if the input was larger than =
5 > >> sec, the output would go high for 5 sec, and then drop to 0. If =
the > >> input droped before 5 sec was up, you wanted the output to drop =
as well. > >> Then you wanted it to wait until the input went high again =
before doing > >> that again. > >> This device has a relay (why would =
you need a relay for 50ma? Most ICs > >> can handle an ouput current of =
50mA at 12V without the need of a relay. > >> > >> This kit is an =
oscillator, where you can adjust the time it is on and the > >> time it =
is off with the pots. It has no input. > >> > >> It uses a 555 timer =
chip. The primary design of the 555 is to initiate a > >> pulse when the =
input goes high, and stays high for the requsite time > >> even if the =
input drops again. If the input stays high beyond the time > >> Ie, I =
think you want to think your way through what you need carefully. > > > =
> Thanks, yes you're right. What value resistor could I substitute for =
RV1 to give a pause time between pulse to 10 minutes? > > RC=3Dt =
roughly. (depends on exactlywhee in the charge/discharge cycle the > =
thing triggers). But R probably should not be much over 1Mohm, as > =
otherwise the input resistance of the ic becomes important. > Then C =
should be about 600uF (probably not electrolytic as the internal > =
resistance can become important but finding anything else at that size > =
is pretty impossible) - Thanks. I think I'll put a fixed 2M ohm in =
series and see if I can get a 3-5 minute range. =
http://www.vellemanusa.com/downloads/0/minikits/manuals/manual_mk111.pdf =
If I disconnect pin 7, would that make it a one-shot pulse?

Jeeeeeze, If you'd have bought the damn Altronix 6062 you'd have been up =
and running in 15 minutes instead of EF-en around with this $5.00 piece =
of crap.=20

I just don't understand some people I guess.

=3D=3D=3D

Time is not a big deal for me.   This is more of a learning project for =
me.