Re: Looking for a Low Cost On Delay Timer

[Jim <alarminex@xxxxxxx>]

On Thursday, August 29, 2013 1:17:30 PM UTC-4, Guv Bob wrote:
> "Guv Bob" <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote in message news:ft6dn=
aIbSdpI-YPPnZ2dnUVZ_vednZ2d@xxxxxxxxxxxxxxxx "unruh" <unruh@xxxxxxxxxx> wro=
te in message news:WxsTt.233047$Z84.231177@xxxxxxxxxxx > On 2013-08-28, Guv=
 Bob <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote: > > "unruh" <unruh@invalid.=
ca> wrote in message news:lAHSt.180556$po1.28313@xxxxxxxxxxx > >> On 2013-0=
8-26, Guv Bob <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote: > >> > "Guv Bob" <=
guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote in message news:1_udnQ7rBpNjRo7PnZ=
2dnUVZ_sidnZ2d@xxxxxxxxxxxxxxxx > >> > Names can be confusing, so here's wh=
at I'm doing.... > >> >> > >> >> http://img43.imageshack.us/img43/7434/wvm.=
gif > >> >> > >> >> When 12VDC is applied to the input, I need a 12VDC outp=
ut 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 le=
gs is in the 10-50ma range. > >> >> > >> >> A simple on-delay timer would w=
ork 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 pu=
t something together from components but my brain is too far behind these d=
ays. 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.vell=
emanusa.com/downloads/0/minikits/manuals/manual_mk111.pdf > >> > >> Except =
that looks like an oscillator rather than a "oneshot" > >> You said that yo=
u 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 befo=
re 5 sec was up, you wanted the output to drop as well. > >> Then you wante=
d 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 rela=
y. > >> > >> 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. > >> > >> I=
t 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 re=
sistance of the ic becomes important. > Then C should be about 600uF (proba=
bly not electrolytic as the internal > resistance can become important but =
finding anything else at that size > is pretty impossible) - Thanks. I thin=
k 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 an=
d running in 15 minutes instead of EF-en around with this $5.00 piece of cr=
ap.=20

I just don't understand some people I guess.