The sensors of this liquid alarm are formed by two pieces of wire with the ends peeled off. The relay depends on the supply voltage that can be between 3 and 12 V. The transistors can also be the BC548.
This latched alarm uses a double relay for this purpose and can control higher power external...
This circuit was found in an old American documentation on telecommunications. It is suitable for...
Taking advantage of the comparator setting, we can use the Norton amplifier as an over temperature...