This circuit was found in a Ferranti documentation from 1969. The transistors are common types of the company at the time. Smaller equivalents may be used. The output power is of the order of 150 mW.
The circuit shown in the figure is suggested by Intersil (www.intersil.com) and makes use of the...
We found this version of the automotive tachometer in a 1980s publication. Variations from other...
The battery charger shown in the figure uses two 60 W incandescent bulbs in series to limit the...