Looking for a Low Cost On Delay Timer

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.

What discharges that 1000uF (and the 1uF) when the transistor isn't turned on? Or are you assuming push-pull drive on the 12V?

Maybe replace C2 with a resistor and put 1K/12V zener before the cap.

On a sunny day (Thu, 29 Aug 2013 14:26:57 -0400) it happened Spehro Pefhany wrote in :

I am assuming other loads on the 12 V supply. If it makes you happy, add a signal light bulb. :-)

No, I found this on ebay looking for something else.

But Google found the spec for the relay:

(unless you ment relay)

seconds. Then output will go back off and stay off until the input goes to zero. Then cycle starts again.

one with NC contacts. Tons of stuff $100+, but for this application, it has to be under $20.

Thanks hamilton. There are a bunch of these from various mfr on ebay but all come from China -- 3-4 weeks.

seconds. Then output will go back off and stay off until the input goes to zero. Then cycle starts again.

one with NC contacts. Tons of stuff $100+, but for this application, it has to be under $20.

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...

Welp.... as I was connecting the last component, my super strength kicked in and I broke diode D1. Even so, I connected it to 12V. The LED came on and stayed on all the time, regardless of how either VR is set. NO stays open and never switches.

So I figured what the heck.... I pulled out D2 and installed it for D1, then jumpered that loose end of R1 to pin 8. Same result, only now the LED doesn't energize.

Rather than keep monkeying around with this one, I'll get another one at $5 and be more careful this time.... and have a handful of spare parts.

Stay tuned....

Yes, I have to think twice, do I save 1/2 the cost or do I need it now.

hamilton

PS: This is what I was looking for, when I found the Delay-Timer-Module:

This I'll wait 2-3 weeks for.

Will this work?

Size R & C so that when switch closes, relay energizes after 5 seconds, and remains energized until switch is opened.

On a sunny day (Tue, 3 Sep 2013 16:01:31 -0700) it happened "Guv Bob" wrote in :

Yes, but 5 seconds needs a big C.

Bob"

Thanks Dave. That's exactly what I have been looking for. Problem is I can only find these or similar units in the $5-20 range from China (2-3 weeks). Omron and others available in US are $70+

Bob"

is I can only find these or similar units in the $5-20 range from China (2-3 weeks). Omron and others available in US are $70+

What circuit is that? I don't see it.

It was an ascii-art sketch I posted when you asked about the 555 chip

you've got most of the parts you need in that Velleman kit

in------+-------------+ | | | . . . .|. . . . | . VCC(8) . | . . +-----+-------RES(4) OUT(3)------ out _|_ | . 555 . D1 A [R1] +---TH(6) DIS(7)-- 'T` | | . . +-----+---+---TR(2) CV(5)-- | . . C1 ===== . GND(1) . | . . . .|. . . . | | ----+-------------+--- ground U1 LMC555 / 7555 etc... D1 1N914 / 1N4148 C1 10uF R1 470K

in------+-------------+ | | | . . . .|. . . . | . VCC(8) . | . . +-----+-------RES(4) OUT(3)------ out _|_ | . 555 . D1 A [R1]

"Guv Bob"

after 5 =

Problem is I can only find these or similar units in the $5-20 range from China (2-3 weeks). Omron and others available in US are $70+

.|. . . .

Thanks, fellows. Sorry for my ignorance -- I tried viewing this in fixed pitch and still can't make out the connections. Any way to sketch it out and upload it somewhere or post it at one of the binary groups? These are active... alt.binaries.schematics.electronics,alt.binaries.schematics.electronic Bob

John mangled it when he re-posted it. the one I posted at about the same time should be readable