VE09M00600K-- Circuit Protection

A Varistor, or Metal Oxide Varistor (MOV), is a general term for a thermally protected, solid-state device that changes its resistance to divert excess current away from circuits. This device is also known as a Transient Voltage Suppressor (TVS), which is used to protect a circuit from transients. This article examines the application field and working principle of one such device - the VE09M00600K.

Applications

The VE09M00600K Varistor is a general purpose device that offers protection for a wide range of electronic equipment. It specifically provides protection against overvoltage transients and surges, such as those due to lightning or power line faults. It is ideal for use in industrial, telecommunications, automotive, audio/visual, and medical applications. Due to its high surge current capabilities, it is suitable for ac power line applications as well.

Design

The VE09M00600K is a snap-on Varistor designed for easy mounting on printed circuit boards. It is constructed of two zinc oxide discs of about 12mm diameter, which are glued together and sealed using epoxy resin. The discs are insulated using a polyester film on the outside which also serves to protect them from damage. The discs are also connected to two metal terminals which provide the connection to the circuit.

Working Principle

The Varistor works by changing its resistance depending on the voltage applied. When the voltage is low, the resistance is high, and the current is limited. As the voltage increases, the resistance decreases, allowing more current to flow. When the voltage reaches a certain threshold, known as the “clamp voltage”, the current is then diverted away from the circuit to protect it from damage. This is known as the “clamping effect”.

Conclusion

The VE09M00600K Varistor is a general purpose device designed for use in a variety of applications. It provides protection against overvoltage transients and surges, and has a high surge current capability. It consists of two zinc oxide discs, sealed with epoxy resin, which are connected to two metal terminals. It works by changing its resistance depending on the voltage, which in turn provides the necessary protection for the circuit.