This circuit was found in a 90s Electronics Now. The maximum current is 1.5 A, given by the regulators. Regulators must be provided with heat sinks.
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...