Microammeter (T465E)

Found in a 1948 MIT documentation, this circuit uses a 0 to 100 uA microammeter as an indicator. The power supply is 150 V.

Light Alarm (CB24967E)
Based on the CA3140 IC, this circuit was found in the June 1986 issue of Radio Electronics....
Dryness Alarm (CB11960E)
When sensors X1 and X2 stop driving by the dryness of the monitored location, the oscillator...
Proximity Switch (CB6410E)
This circuit works directly connected to the network and special care must be taken with its...