HVR Silicon carbide varistors are composed of approx. 90% silicon carbide of various grains and approx. 10% ceramic binder and additives.
After shaping, the varistors are sintered at high temperatures in specific ambient conditions. The electrical contact is manufactured by spraying on a metal layer. The electrical connection is by soft soldered tinned copper wires.
The HVR SiC varistors have good voltage dependences and high energy absorption. They are manufactured mainly as discs with varying sizes, as the required electric values are most easily obtained with these geometric dimensions.
One of the most advantages of a SiC Varistor is the behaviour in the case of a fault. It has a self-healing characteristic and doesn´t shorten the circuit.
Advantage of HVR SiC products
- Varistor dimensions can vary in a wide range. Customer specified dimensions are possible. SiC ceramic has generally a self healing characteristic. This means the varistor is evaporating the failed part of the ceramic. Now he is protecting the circuit against further impulses with slightly reduced energy parameters.
- The temperature stability of our ceramic is higher as the ceramic of our competitors. This is a result of over 70 years of SiC ceramic development in our company. Our SiC ceramic can bear the following temperatures:
- Continuous 150°C
- Short time 170°C
- In case of failure up to 180°C
- We have tested our ceramic and also the one of our competitors in al long duration test with load under a temperature of 200°C. This has shown that our ceramic withstand this conditions at least 2 times longer as the others.