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Guv Bob Guv Bob is offline
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Default RC Circuit for On Delay Timer

Thanks, everyone, for all the educational info. I will hang around here regularly now.

I got what I needed by buying a MK111 time kit and modifying it - ended up with a the Delay on Make (or Power On Delay) timer. To try and head off the questions about nominclature ... this type of relay delays the power coming on to the load for a preset time. That's why it's call an "On Delay" timer -- it delays the power when turned on.

The different here is that I'm using the NC contact on the relay instead of the usual NO contact. So the power to the load is "on" when the 555 circuit is energized (thru NC), and is then turned off when the relay is energized.

Anyway, back to the practical stuff...

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.... try not to laugh...
http://img401.imageshack.us/img401/6528/9oag.jpg

Anyway, I made the changes Spehro mentioned and it works perfectly!

First I snipped 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 puting the relay 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