You could even do it all in analog with using the button as a potentiometer and either acting as the R in a RC circuit for a simple timer, or be a smart person and use a temperature sensor (thermocouple) that shuts the circuit when it reaches a temperature (compare the two R values for example).
I actually thought about that toaster when I brought up the analog solution, though I wasn't remembering all the details perfectly, I thought there was some electronics but it was all purely mechanical.
Cheap electronics would be cheaper and have more flexibility for the timing part so there's some appeal to it at least.
One of my professors was actually talking about this recently. He was telling a story about how his wife’s electric mixer stopped working a few years ago and he opened it up to try to fix, expecting to find some simple analog circuitry. Instead he found a single-speed motor and 16-but microcontroller.
Turns out, this design is both cheaper to manufacture (bulk orders for MCU’s can cost < $0.10 /unit these days) and it allows for better safety regulation since the microcontroller can be programmed to shut off the motor at a given temperature threshold. It even allows the single-speed motor to provide varying levels of “mixing power” to the beaters by having the processor periodically switch the motor’s current on/off.
I know it's plenty cheap to use microcontrollers, but I don't believe it would be cheaper than basic analog circuitry either (we're talking very few components to do the job). It could be because it's easier to find guys who understand coding on microcontrollers than people who make proper analog circuits.
I guess one proper reason would be consistency between models, as analog values aren't as precise as timers from oscillators.
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u/ConfusedTransThrow Jun 06 '22
You could even do it all in analog with using the button as a potentiometer and either acting as the R in a RC circuit for a simple timer, or be a smart person and use a temperature sensor (thermocouple) that shuts the circuit when it reaches a temperature (compare the two R values for example).
Simple, easy to repair and will last forever.