This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two 9 V batteries since it requires a symmetrical source.
This speed control for motors up to 500 mA was obtained in an old European documentation, but it...
This circuit cuts a rectangular signal, and a trapezoidal signal is obtained. The circuit is from...
This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational...