1. Another option, particularly for high voltage circuits , is to use a pre-charge circuit. 2. The problem was in the low voltage circuit internal to the power amplifier. 3. The burden voltage can be significant in very low-voltage circuit areas. 4. High pressure compressed air also works nicely to operate high voltage circuit breaker mechanism. 5. Some high voltage circuits are often erected on the same tower as 110 kV lines. 6. The characteristics of low-voltage circuit breakers are given by international standards such as IEC 947. 7. In small mains and low voltage circuit breakers, this is usually done within the device itself. 8. Sulfur hexafluoride is generally used in present high-voltage circuit breakers at rated voltage higher than 52 kV. 9. Low-voltage circuit breakers are also made for direct-current ( DC ) applications, such as DC for subway lines. 10. It is now possible to use low-energy spring-loaded mechanisms to drive high-voltage circuit breakers up to 800 kV.