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 circuit appears elsewhere on this site, but from different sources. Using the LM3900, we find this...
Suggested by Popular Electronics, it is a digital amplifier, for pulses with frequencies up to a...
July 25, 2016 –Mouser Electronics Inc. is teaming up with celebrity engineer Grant Imahara for the...