Countdown Timer to Turn Off Device

Any hardware or drug store?

Without a current spec on the heater, you are only gong to get guesses.

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Good morning, Mr. Watson. If you're looking for an electrical component instead of, say, just a darkroom timer (Gra-Lab), you'll want what's called a "delay off" time delay relay. Two hour TDRs are available from many sources. I like SSAC for inexpensive solid state and relay contact TDRs. The classics are made by Potter&Brumfield.

Generally for long time delays, the TDR will have a trigger input sparate from device power. For "Delay Off", the relay will just turn on when you trigger it, and remain on for the set time delay.

If you could describe a little more about your application, possibly you could get more specific advice.

Good luck Chris

Just get a 24hour programable timer from, say Ikea, £3.75 UK !

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Best Regards:
                      Baron.

Good point. 1500W is the highest value selectable.

Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

--
               "Suppose you were an idiot. And suppose you were a
                member of Congress. But I repeat myself."
                                 -- Mark Twain
                     Web Page:

I'll take a look at some of these suggestions. I'll repeat the added info I provided above to an earlier poster, 1500W heater.

During this post some of it unlodged a a memory that I may have a Radio Shack device that does this. The trick now is to find it. My first attempt failed.

Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

--
               "Suppose you were an idiot. And suppose you were a
                member of Congress. But I repeat myself."
                                 -- Mark Twain
                     Web Page:

The Ikea device is rated at 13A 240v about 3.3Kw. In the states I suppose it may only be half that loading at 115 volts ?

--
Best Regards:
                      Baron.

Yes. Usual heaters sold there are 1500 W, 15 A @ 120 V

Thanks. I suspected as much.

--
Best Regards:
                      Baron.

I

Hi, Mr. Watson. Baron has a great idea, especially if you're using one of those digitally programmable outlet timers. You can just plug in a

120VAC coil relay that can handle the current of your heaters, and you're good to go.

I don't trust the accuracy and repeatability of those ones with the small gearmotor and the pegs to turn things on and off.

Good luck Chris

In looking over the responses, it looks like maybe there was some misunderstanding here. What I want is a pretty much self contained unit that I can plug the 1500w heater into, and turn a knob to say 30 minutes, and 30 minutes later the heater goes off. What I'm looking for is a *countdown* timer like the one you find in the bathroom of a motel that operates an infrared light. I could likely make one of these from the parts at our local h/w store, but that's not my goal. I want it already to go. Go home plug, it into the wall, and plug the heater into countdown timer.

For the record, the local h/w sells countdown timers like those used for the infrared light for 30 minute, 60 minutes, and 12 hour intervals. I could put it into an electrical box along with a socket, and run a cord out to the wall outlet. I have no interest in doing this at the moment. Seems like what I'm asking for should be commonplace, but I guess not. Possibly some safety issue?

Nevertheless, I'll pursue the ssac and tycoelectronics URLs Monday.

Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

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                     Web Page:

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I guess I understand what you're really looking for now. I believe the closest you can get would be a Gra-Lab darkroom timer. That's pretty much what I'd use, except for the 1500 watt requirement. Standard GraLab timers are rated to 10 amps/1200 watts resistive.

I know at one time, GraLab had a non-standard, special order with 15A microswitches. You might want to contact them:

Good luck Chris

they keep good time, they just don't trigger with precision.

Bye. Jasen

This question was done to death about 6 months ago, per-built plug-in unita are available.

Bye. Jasen

And the answer was?

Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

--
                      "Apollo to Mission Control
                       We are almost in reach of our goal,
                       But our readings of g
                       Seem excessive to me,
                       So we may be inside a black ho....." -- Unknown
                     Web Page:

(i meant pre-built above)

some place the other side of the pacific ocean where the electricity runs at the wrong voltage. I didn't make a note of it.

search this newsgroup (or possibly one of the other electronics groups) for likely the words darkroom, kitchen, and timer, and it'll turn up the thread.

Bye. Jasen