A simple low-cost sinusoidal signal generator for your workshop

This construction project features a very useful low-frequency signal generator that is simple to make at low cost. In the early days of telegraphy by wires, Sir Charles Wheatstone produced a d.c. bridge-circuit for the measurement of electrical resistance. By adding two capacitors to Wheatstone's bridge, Wien's converted it to an a.c. brodge capable of measuring capacitance, inductance, and frequency .Wien's dual resistor/capacitor (RC) circuit was later adopted as the feedback circuit by which to convert an amplifier into an oscillator.

Standardized components are used to provide a functional and reproducible piece of electronic test equipment. Powered by a 9V battery at 10mA, it produces a sinusoidal signal of resonably constant amplitude at about 2V peak-to-peak over a frequency range of approximately 10Hz to 140kHz.