What is an oscillator bridge?

The bridge oscillator is an electronic oscillator that generates a large frequency range in the form of sinus waves. The oscillators are circuits that produce recurring electronic signals. They are often used to transmit TV or radio signals or create sound for electronic devices. The sounds produced by an oscillator cannot be heard by themselves, but must be converted into audible sound using speakers or other devices. The oscillator of the bridge is often used as an audio frequency oscillator because it is easy to tune it and has low distortion.

The word bridge concerns the structure of the used circuit. The bridge circuit is an electrical circuit in which two branches of the perimeter are overwhelmed or crossed by a third. The circuit branch is any electrical circuit that is divided into two or more parallel circuits. This results in each circuit to receive half of the current coming from the main line. The bridge consists of four resistors and two capacitors.

The structure of the bridge oscillator isFounded on a network developed by German physicist Max Wein in 1891. As a result, the bridge oscillator is sometimes referred to as the Wein oscillator, even though Wien did not actually create it. The technology needed for oscillators did not exist for decades after Wein created its circuit.

Credit for creating the Bridge oscillator actually goes to William Hewlett. He first described this type of oscillator in the master's degree, written for Standford University in 1939. Hewlett was founded by Hewlett Hewlett-Packard (HP) with David Packard. Hewlett and Packard used the technology described in its work to create the first HP, HP2001A product. Hewlett was awarded a patent on the design of the bridge oscillator in January 1942.

One of the main advantages of this type of oscillator is the distortion. This is only possible because the amplitude or size of a change createdis well stabilized. Hewlett achieved this stabilization using a bulb as a thermistor.

Thermistor is a resistor that changes its resistance depending on the temperature. The bulb resistance increases as temperature increases. The bulb is therefore a positive temperature coefficient thermistor. Since the first hewlett oscillator, bulbs have been replaced by diodes or other types of thermistors that are less sensitive to vibrations.