What's this called?

Question

Hi, I need to turn off a certain electronic device X hours (3-4) after i start it. I want this to happen automatically, so I need something that goes between the device and the power outlet, which will automatically switch off the juice after X hours, as if the device was unplugged. I want it to be as easy to use as possible, so that there's just some dial or some buttons where I can set the time after which the device is to be turned off. It's running off of north american standard 120 V, 60 Hz, and if the device is turned off reliably there could be a sfatey hazard.

What kind of thing would do the job/what's it called?

Thanks.

Bob Myers · Accepted Answer

Ummmmmm.....a timer?Or are you really asking how to build one?Bob M.

John Fields · Answer

---A timer, but if there could be a safety problem if it's turned offreliably,  I'd call it a problem.-- John Fields

Jim Thompson · Answer

;-)                                        ...Jim Thompson-- |  James E.Thompson, P.E.                           |    mens     ||  Analog Innovations, Inc.                         |     et      ||  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    ||  Phoenix, Arizona            Voice:(480)460-2350  |             ||  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  ||                  |    1962     |             I love to cook with wine.      Sometimes I even put it in the food.

CWatters · Answer

Normally a "limit timer". Sometimes found on pottery kilns.

JeffM · Answer

Go to the electrical section of any good hardware store. There are 24-hour timers that plug directly into a wall outlet for ~$4. The resolution is about 3 minutes (lash of the mechanism). I have seen many of these in second-hand stores. I once found a Intermatic DT1 digital unit that has 1 second accuracy.

Jerry Greenberg · Answer

I needed something like this a number of years ago.

I went to a large hardware center, and bought an electronic programable timer unit. It plugs in to the AC and then the load plugs in to the timer. It is easy to program, and it can be programed to perform a number of combintation of functions. I think I paid about $40 or something like that.

The load is switched by a relay in this one, thus the load is isolated from the AC line when it is turned off with the timer.

You cannot use anything that is dependent on the AC power to maintain any setups in its memory. Many appliances and home entertainment equipment must have the AC connected to it when it is in its off condition.

Jerry G. =========

Wim Ton · Answer

Get an old fashioned electromechanical timer, the thing with a ring around it where you stick little pins in. Use it the wrong way round, connect the outlet (socket) to the mains and and the inlet (pins)to the load. This ensures that when the load is switched off, it will not come on again after

24 hours. Ensure with glue or tape that the uninitiated and the ingnorant do not get exposed to plugs and sockets that are used the wrong way round

Wim

What's this called?

Join the Discussion

Didn't find your answer?