"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

Kitchen timer (help me rid myself of this idea)

Started by royalbox, December 08, 2018, 04:21:44 PM

Previous topic - Next topic


First, let me say that I'm not into novelty things or things pretending to be one thing that are another as a rule.

However, there are plenty of old phones around, 746's for example, and I though a way to actually use the phone other than for phone calls (which I admittedly hardly ever make) would be as a kitchen timer. Lift up the receiver, dial in the minutes and replace the receiver. When the time is up the phone would ring, then stop after one minute or until the receiver is picked up again.

Maybe an Arduino project. It would be making use of both the dial and the ringer so not as crass as a lamp conversion perhaps. Main problem to overcome I would think is ringing the bells.

Anyway, shoot me down in flames if you like!


As long as you are not destroying a phone, go for it!
Harry Smith
ATCA 4434

"There is no try,
there is only
do or do not"

Jim Stettler

I believe in keeping  modifications reversible, and keeping the old parts.
My guideline,

Jim S.
You live, You learn,
You die, you forget it all.

Butch Harlow

Butch Harlow


Use a raspberry pi and when you lift the handset it can talk to you and tell you how many minutes remaining

I have an alarm call facility on the PABX but it hasn't occurred to me to use it for culinary porpoises.


     Regular Member Post

Okay, I appreciate the creative ingenuity of coming up with this idea but having done many things like this in the past, and getting half way through the project realizing I wish I hadn't thought of the project, much less started it, I have to say "why?"

First, when completed, you will end up with a large object on the kitchen counter that will be hard to keep clean (kitchen, splatter, general crud and airborne grease that accumulates daily) and knowing that there are better timers, multiple countdown channel timers, which would be more useful since cooking is usually doing more than one thing at a time and they can be purchased for under $20.

Here's one example

And this one has a feature that when the count down ends, it beeps until silenced and if not in the room when the countdown ends, the timer channel then begins to count up so upon entering the room to turn off the timer, one can see how long it has been since the countdown stopped - how over cooked one's absence meant to the food. I don't think one could build a phone to do all that and run on 2 AAA batteries and the time commitment is another.

I fully understand the desire to do this, been there and done that with other ideas, just to say it can or was done but the practicality or the beauty of a "phone" timer is certainly in the eye of the creator/builder. I guess that's the same way lamp phones came to be decades ago.

I wish my wife read this forum for this 3 channel timer would be a great Christmas present for me . . .   ;)


Thanks for all the responses. I have to say though that it was just an idea, I'm not necessarily going to do it myself.

Teleplay, it's not really about the timer, more the fun in making it.


a count down timer for a phone, good idea. now how the heck are we gonna wire the thing up??


Yes, count down timer is a better description.

I wonder if it may be easier to get a GPO 722 trimphone to ring than activating bell coils (I have one that I plan to restore). Also, the trimphone has an illuminated dial, so you could have 10 small LEDs under each number that could turn off for each 10% of the remaining time. No idea how to do this by the way, just putting the idea out there for fun.

There's an open source pulse to DTMF converter that would have the necessary code for detecting pulses. I did build one and it works well. The code could be converted for Arduino.

Also, I agree that everything should be reversible, and I don't see that being a problem.


Quote from: royalbox on December 09, 2018, 12:33:16 PM
Teleplay, it's not about the timer.

Yes, I realize that, but have to thank you because after doing the timer search for prices, I bought that one for myself. I really didn't know they came with 3 timers in one unit, a handy thing.


Here's a slight turn on your idea to think about. How about an alarm clock. Lift the receiver, dial the time you want the phone to ring (military time using 4 digit dialing), go to sleep and wake up to a C4A or B1A ringing. Lift the receiver to turn the ringer off. A night stand would be a lot cleaner over time than a kitchen counter top and I think an alarm clock would be a widely accepted use - getting power to the ringer, a ring generator, would be the hard part but those 12 VDC to 70V 20Hz PowerDsine ring generators

are very nice and I have used them to test ringers for years using 2 27A 12VDC batteries in 27A battery holders.

2 batteries have lasted over a year testing ringers. So, doing the electronics to get the phone to work as an alarm clock would be difficult since the ring generators are out there ($20 for the dSine plus $1 for two batteries and $1 for the battery holder and that part is done). Any rotary phone housing with a ringer and dial would work. Don't need the network. Lot of 302 bases, B1A ringers, housings and handset parts out there so no need to destroy or re-purpose a working phone. All it takes is money, time and the electronics know how. I'd put one on my night stand.

Ideas are easy and cheap and fun to think up, it's the getting to the final result that I find the hard, time consuming and many times the costly part.

Now, I have 4 302 lamp phones (bought them that way and nicely restored them). How about a timer circuit that turns the lamp on, or off programmed by the dial. Of course, since the handset is fixed, turning the dial would be the only option so dial 1 for one hour on, 9 for 9 hours on and 0 for off. Or dial 0 to enter program mode and then 1 to 9 for the hours until the light comes on. Or dial 0 once for time to off, dial 0 twice for time before coming on and dial 0 three times to clear the programming.

Actually, a DTMF pad with the # and * would make programming a lamp or timer a lot easier and more versatile than a rotary dial.

Note: these thoughts above are theoretical and in no way responsible for the conversion and/or destruction of any telephone.


Interesting idea about the alarm clock. By the way, you may not have noticed but I edited by previous post earlier as I though "it's not about the timer" on it's own may come across as a bit rude.

I'm in the UK by the way so looking at GPO 746 or maybe 722. The 722 trimphone would be a good alarm clock as it has a rising volume setting for the "ring" (warble). Haven't heard mine working yet, it's a restoration project. Maybe the electronic ringer would be easier to get working with something of low voltage / current.

EDIT: That ringing voltage generator looks interesting, available on UK ebay also.

Butch Harlow

Exactly as I expected nobody is talking you out of it. Plus, some pretty cool ideas on how to move forward. I can't wait to see the working model. Get to work, sir. Haha!
Butch Harlow


Well, I just ordered a cheap Arduino development kit thing from banggood for about £2.50 so I'll hopefully be able to experiment with getting pulses from the dial. Probably going to take about a month to get here. Need to learn about Arduino coding, think it's similar to C. Something interesting to do anyway.