Suggested by an American publication, this circuit has 5 operating conditions indicated in the diagram. The circuit can be designed based on modern equivalent transistors.
The Texas Instruments TPS80 LDO (Low Dropout) series (www.ti.com) can provide output voltages from...
The transistors of this circuit may be general purpose and the power supply comes from the TTL...
Another of the many tachometer circuits we have on our site. This one is from the September 1976...