This circuit was found in Mullard's transistor application manual from 1960. More modern transistors can be used. The zener diodes used have the indicated voltages.
Found in older documentation this setting applies to modern components, noting that the power...
This circuit can send signals in both the VHF and FMN bands with a range of a few tens of meters. The...
This circuit indicates when the voltage of a 12 V battery is low. With changes, for example, the...