The sensor of this circuit found in Popular Electronics can be formed by a piece of fabric between two bare wire screens. When wet, the fabric will pass the current between the screens, triggering the alarm.
With an output power of 1.5 W under a 12 V supply, this circuit makes use of transistors that are...
Amphenol Sine eco | mate ™ connectors can be purchased from Mouser Electronics for a variety of...
This circuit is from an old 80's linear circuit manual. The configuration can be implemented with modern...