Hey guys,
I'm making an alarm that produces regular timed beeps whenever its probes are connected by water (well, strictly speaking coffee, not water). I have a working prototype now, based on a two transistor flasher circuit, but I want to use a 555 to time the beeping instead. In my simulation, wiring the 555 to the MOSFET source seems to work well, but I can't test it the other way around (load on drain), because the application uses an implicit ground for the 555. Anyway, do you think wiring the 555 to drain will work better?
I've attached the circuit as it is now. The 30k and switch models the coffee liquid. The pots adjust frequency and duty cycle. The 2.8k is a piezo beeper.
I'm making an alarm that produces regular timed beeps whenever its probes are connected by water (well, strictly speaking coffee, not water). I have a working prototype now, based on a two transistor flasher circuit, but I want to use a 555 to time the beeping instead. In my simulation, wiring the 555 to the MOSFET source seems to work well, but I can't test it the other way around (load on drain), because the application uses an implicit ground for the 555. Anyway, do you think wiring the 555 to drain will work better?
I've attached the circuit as it is now. The 30k and switch models the coffee liquid. The pots adjust frequency and duty cycle. The 2.8k is a piezo beeper.
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