We found this circuit in the old Mullard transistor reference manual from 1960. The circuit is powered by a single battery and the transistors are germanium common at the time.
The circuit presented was suggested by a Texas Instruments optoelectronics manual. The voltage...
This cassette player motor speed control was found in the January 1991 issue of Radio Electronics...
This is an old circuit with a homemade sensor found in the September 1995 Electronics Now...