This circuit was obtained in a Electronics World of 1968. The transistors can be equivalent as the BC558 for the PNP and the BD135 for the NPN powering lamps from 3 to 12 V according to the supply.
The voltage regulator circuit described is highly accurate and uses discrete components...
WWV is the standard frequency station of the United States government. This station broadcasts a...
Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then...