"Spehro Pefhany" wrote in message ...
On Thu, 29 Aug 2013 10:18:17 -0700, "Guv Bob"
wrote:
"Guv Bob" wrote in message m...
"Spehro Pefhany" wrote in message ...
On Sun, 25 Aug 2013 23:29:54 -0700, "Guv Bob"
wrote:
"Guv Bob" wrote in message m...
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.
===
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...nual_mk111.pdf
It can be modified to do what you say you want.
- Hmmmm....... in that case, forget the electronics! ;O)
http://www.vellemanusa.com/downloads...nual_mk111.pdf
If I disconnect pin 7, would that make it a one-shot pulse?
Try leaving out R2 & RV1* and D2*, and jumper the free end of R1
(R1-D2 junction) to pin 8.
If you can't quite get 5s with RV2 cranked up all the way, increase R1
to 10K or 20K.
*optionally; if they're already in there, don't bother taking them
out.
Well, I made a real mess of the first board, thanks to a new Weller soldering iron. Ended up digging out my old Radio Shack iron which worked 10 times better - same type and wattage as the Weller. Here's the soldering job on each board....
http://img401.imageshack.us/img401/6528/9oag.jpg
Anyway, I made the changes Spehro mentioned and it works perfectly!
First I snipped the R3 out of the circut which caused the LED to act as a one-shot as needed. So with that good news, I added the jumper and now the relay is in the circuit and I am in Fat City!
FYI, on the left is the assembled board from the kit. Right shows it with the jumper added.
http://img835.imageshack.us/img835/6691/0wxx.jpg
http://img17.imageshack.us/img17/4276/g1k.gif
Thanks again to all for this very educational journey!
Bob