We found this circuit in 1969 American documentation. FETs admit equivalents, as do transistors. The circuit can be used as a shield.
The sensor for this alarm is an LDR and it consists of an oscillator that goes into action when...
This circuit shows how to control an astable configuration using the 555 IC. The control signal is...
This circuit was suggested by Radio Electronics magazine in September 1983 in the new ideas...