nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqr3u9x35tp76ejukzt775ysgqr9r299cfqe6f35l5ms5a9ay9qypqrjpqg2 (nprofile…pqg2) nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqtz0478tzq70vnq77m2xw87kzjglzffwtx4sa8xymucq8y48eys7s2q32r0 (nprofile…32r0) Basically any OpAmp can be used in a comparator circuit.
A zehner diode (above a 10k resistor) will give you a fixed reference (say 20V), which you divide via a resistor + potentiometer (i.e. adjustable resistor), to about 12V.
Then you also divide the battery voltage by two identical resistors, i.e. to U_battery / 2. Then comparator via OpAmp and you drive some piezo buzzer or other "loud noise" generator of choice.
(I never built such a device, but I'm pretty sure it'll work as described. Probably somewhat temperature dependent, but not to a relevant degree. I'm willing to draw a circuit diagram if needed.)
Drahflow
npub1tg…k8ckc
2025-10-08 19:12:17 UTC
in reply to nevent1q…d9kx
Author Public Key
npub1tgl9ankrn7vjtwls6w5rernz0lqxakc4vk5r3mtklnxk4nryme3qpk8ckcSeen on
wss://relay.ditto.pubPublished at
2025-10-08 19:12:17 UTCEvent JSON
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