| 摘要 |
<p>The overvoltage circuit (7) is connected in parallel to the two connection terminals (2,3) of the circuit to be protected, and comprises n series connected components (10-1 to 10-5) fulfilling the function of a zener diode. The individual components (10-1 to 10-5) have a low power rating relative to the levels of overvoltage and are coupled to the control terminal of a power switching device of high power rating. An overvoltage causes a turn-on signal to occur, switching the power device into conduction, thus clamping the voltage between the input terminals to a safe level. A resistor is integrated with the device to be protected and is connected in series with a power transistor.</p> |
