This temperature compensated circuit was found in a 1980s American documentation. The power supply is made with 5 V which allows its use as a shield.
This circuit of a 1991 PE Hobbyst Handbook allows the brightness of the incandescent lamp to be...
This circuit is from the old RCA transistors manual of 1964. The transistor can be the BC558 and...
Originally this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...