We found this circuit in the 1957 Raytheon transistor application manual. The transistor can be a BC558 and the common 6 V relay, just by using this voltage in the supply.
In the figure we have a protection circuit for sources that we find in a 1994 technical...
Found in a 1968 Motorola manual, this DC circuit uses components from the era. The circuit fires in...
This circuit was found in an American documentation from 1977. The mechanical resonator or ceramic...