This circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine. The circuit is use do observe signal in an oscilloscope.
This basic configuration of voltage regulator using operational amplifier and zener was found in a...
This 75 W power supply was found in American documentation from the 1980s. Transistors can be...
This circuit was found in a 1987 magazine. It measures the pulse rate produced by a cardiac...