My mom (90, but pretty functional) has occasionally left the range on.

I want to give her a simple twist alarm (think egg timer), but with a persistent alarm that rings loudly until she turns it off. I'd love to buy one, but such a thing doesn't exist.

Seems like this could be built with 2 latch relays, but scrating my head and was wondering if this might be child's play for someone here to design.

I would be happy for someone to take this idea, make a product, and sell it!

Any help is appreciated. I know this can be achieved with more complex devices. Old people need it simple. No additional features.

Eric


Features:

• Use mechanical twist timer 0-60 minutes (probably use A/C fan timer, see picture)
• When activated, an LED comes on
• When the time is up, an alarm sounds and persists
• User hits stop button to stop alarm, and the LED goes out
• Loud!
• Battery powered.

 

Something like this won't work?

The universal problem is activation more than operation. You still have to set it for it to alarm. To have the alarm feature as a automatic setting when a burner is activated (with a heat sensor for a external alarm device) on the range would be much more useful.

 

Below is the LTspice sim of a simple circuit that should do what you want:

It is triggered by the contacts of a mechanical timer with logic provided by a single CMOS CD4001 quad NOR gate package, which drives a transistor to power a Buzzer at the end of the time, until it is reset

The SWtimer (green trace) activates the latch U1a/U1b which sets /Q signal low, but the high signal from the timer keeps the U1c output low and the buzzer off (if either input of the NOR-gate U1c is high, the output is low).
This also activates the LED, D1 (red trace).

When the timer times-out (green trace) then both U1c's inputs are low and its output goes high, turning on the buzzer (blue trace at 11 seconds in the sim).

The buzzer then continues to sound until the reset PB is pressed (Yellow trace) which resets the U1a/U1b latch, making Q low and /Q high, thus turning off the transistor and the LED.

The circuit can be powered by two AA or AAA alkaline batteries.
It draws only a very small leakage current when off so either battery type should last a long time.

Is that doable for you?

 

Something like this won't work?

The universal problem is activation more than operation. You still have to set it for it to alarm. To have the alarm feature as a automatic setting when a burner is activated (with a heat sensor for a external alarm device) on the range would be much more useful.

I agree that a timer on the actual burner circuit would be way better! In fact, as a side note, my stove works that way! I put a pizza in, set it for 20 minutes, and go take a shower, and I don't need to worry. The pizza will be ready whenever I get there. It is great even for me, who still has most of my marbles!

 

Below is the LTspice sim of a simple circuit that should do what you want:

Absolutely FANTASTIC. I'll give it a go! Thank you, thank you, thank you!

 

Any quick recommendations on where to source parts? I haven't tinkered since the days I'd just go to Radio Shack and pick up what I need. I'm sure I'll be able to find a source, but if someone wants to save me the searching, I'm listening!

Electrical Engineer, Georgia Tech, class of 1984!

 

Hi.
I implemented to my electric stove a reminder chirp ~every minute when any surface 'burner' is on; inside the range control panel. Am also with memory problems and before gets worse, got it done. Been working daily for a year now. No mechanical timer, no microprocessor, no knobs/buttons to turn, no complications. Volume adjusts by a piece of tape partially blocking the piezo hole.
Have not done to the oven as sees not much use.

 

Hi.
I implemented to my electric stove a reminder chirp ~every minute when any surface 'burner' is on; inside the range control panel. Am also with memory problems and before gets worse, got it done. Been working daily for a year now. No mechanical timer, no microprocessor, no knobs/buttons to turn, no complications. Volume adjusts by a piece of tape partially blocking the piezo hole.
Have not done to the oven as sees not much use.

Sounds good. Show us what it looks like.

 

Any quick recommendations on where to source parts?

If you don't have a local electronic supplier, you can go to Amazon, Ebay, Alibaba, AliExpress, etc. for cheap (but possibly unreliable) parts.
Otherwise on-line suppliers like Digikey, Mouser, Jameco, etc. are good.

 

Hi.
I implemented to my electric stove a reminder chirp ~every minute when any surface 'burner' is on; inside the range control panel. Am also with memory problems and before gets worse, got it done. Been working daily for a year now. No mechanical timer, no microprocessor, no knobs/buttons to turn, no complications. Volume adjusts by a piece of tape partially blocking the piezo hole.
Have not done to the oven as sees not much use.

I like the simplicity!

My fear for my mom is that she might be in another room or even out tending the garden when she gets distracted. To make it loud enough to handle those situations seems like it would be quite the nuisance. I guess without an auto-shutoff there are always going to be tradeoffs.

She lives alone. And I'm trying to extend the time she can stay there before needing assisted living.

I guess another option would be to move her to use a plug-in hot plate and then use a plug-in timer switch if I could find one with a high enough rating.

We do the best we can...

Thank you for another possible idea!

 

"Alexa, remind me at 7 PM to turn off the oven."

"OK."

 

er i
"Alexa, remind me at 7 PM to turn off the oven."

"OK."


View attachment 344968

Great but you need to remember the reminder.

(burner is the gas, electric or induction heating system)
IMO the best system is one tied to the actual burner or heating system as the trigger event as that's the root cause of needing a reminder to shut it off or to check what's cooking. Above X burner temp (using stove and/or cooktop heat sensor that sees any heat source), the timer autostarts and will alarm in X time. Below X burner temp it stops the timer and alarm if sounding. And one button to silence the hot burner reminder alarm and restart the timing period for the next reminder while the burner is still above X temp.

 

"Alexa, remind me at 7 PM to turn off the oven."

Yep, I like this, and it is the method I use with my iPhone, literally for everything. My mom even has an iPhone, but there is a digital divide between older people and technology. Many people don't appreciate how big a barrier technology can be. I guess with Alexa, she would not have to first find her phone!

 

Yep, I like this, and it is the method I use with my iPhone, literally for everything. My mom even has an iPhone, but there is a digital divide between older people and technology. Many people don't appreciate how big a barrier technology can be. I guess with Alexa, she would not have to first find her phone!

WTF is this "digital divide between older people and technology" thing? We're the generation that invented all this stuff.

I'm 67, and have set up a Dot in most every room, with my lights, two TV's, even my fish tank is set up with commands and automated scripts. My bedroom has an overhead room light, two bedside lights, and my reading lamp, all on their own controllers, with several voice activated scripts to make changes.

 

WTF is this "digital divide between older people and technology" thing? We're the generation that invented all this stuff.

True.
But some in their 90's didn't adapt to it when they were younger (some still have a POTS phone).

 

(some still have a POTS phone).

Or two.

ak

 

WTF is this "digital divide between older people and technology" thing? We're the generation that invented all this stuff.

I'm 67, and have set up a Dot in most every room, with my lights, two TV's, even my fish tank is set up with commands and automated scripts. My bedroom has an overhead room light, two bedside lights, and my reading lamp, all on their own controllers, with several voice activated scripts to make changes.

Using those posting here, as examples of a divide between older people and technology", is like asking old drunks, "why don't older people drink more"? The old drunks would say, we drink plenty.

 

Or two.

When I was a kid, we had an advanced POTS phone on the wall that was voice operated.
We just picked up the receiver and a nice female voice would say "number please".
Then, when I was in High School, the phone company came out and added a rotary dial to the phone (which seemed an advancement at the time, but was really a step back in convenience).

 

When I was a kid, we had an advanced POTS phone on the wall that was voice operated.
We just picked up the receiver and a nice female voice would say "number please".

Wow, I'm y.o.u.n.g.

ak

 

Wow, I'm y.o.u.n.g.

And I'm o.l.d.
Rub it in.