We found this circuit in the July 1969 Radio Electronics magazine. The circuit uses a coupler made with a lamp and an LDR. The power of the lamp determines the types of diodes.
This circuit was found in Electronics Now magazine and can be applied to any JFET. The circuit has high...
When this alarm is off current drained is very low, only about 60 µA. The circuit can be powered...
This circuit was published in an English magazine from 1977, but it can be easily assembled since...