Countdown Timer to Turn Off Device

[Watty]

I'd like to attach such a timer (Subject) to a heater and set it for say 30
minutes. At that time, it would turn off the heater. Where would I find one
that is ready to go, that is, is selfcontained, no need to solder or add
anything? A two hour timer would be good.

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

 

[Homer J Simpson]

I'd like to attach such a timer (Subject) to a heater and set it for say
30 minutes. At that time, it would turn off the heater. Where would I find
one that is ready to go, that is, is selfcontained, no need to solder or
add anything? A two hour timer would be good.

Any hardware or drug store?

 

[JeffM]

I'd like to attach such a timer (Subject) to a heater
and set it for say 30 minutes.
Wayne T. Watson

http://froogle.google.com/froogle?scoring=p&price=between&price1=1&q=appliance-timer
http://www.google.com/images?q=Darkroom+Timer
Without a current spec on the heater, you are only gong to get guesses.

 

[Chris]

I'd like to attach such a timer (Subject) to a heater and set it for say 30
minutes. At that time, it would turn off the heater. Where would I find one
that is ready to go, that is, is selfcontained, no need to solder or add
anything? A two hour timer would be good.

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: <home.earthlink.net/~mtnviews>

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.

http://www.ssac.com/
http://relays.tycoelectronics.com/

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

 

[Baron]

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.

http://www.ssac.com/
http://relays.tycoelectronics.com/

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 !

 

[Watty]

http://froogle.google.com/froogle?scoring=p&price=between&price1=1&q=appliance-timer
http://www.google.com/images?q=Darkroom+Timer
Without a current spec on the heater, you are only gong to get guesses.

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

 

[Watty]

Chris wrote:




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

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

 

[Baron]

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.

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 ?

 

[Homer J Simpson]

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 ?

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

 

[Baron]

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

Thanks. I suspected as much.

 

[Chris]

I'll take a look at some of these suggestions. I'll repeat the added infoI
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: <home.earthlink.net/~mtnviews>

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

 

[Watty]

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

 

[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

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:

http://www.gralab.com/products/index.asp

Good luck
Chris

 

[jasen]

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.

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

Bye.
Jasen

 

[jasen]

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?

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

Bye.
Jasen

 

[Watty]

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: <home.earthlink.net/~mtnviews>

 

[jasen]

(i meant pre-built above)

And the answer was?

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