| 摘要 |
A solid state protective device is disclosed which monitors an electric quantity such as current or its negative phase sequence component in a protected circuit and which responds to abnormal increases in the value of that quantity by activating a circuit breaker or warning device after a period of time which is a non-linear inverse function of the magnitude of the circuit quantity being monitored. The device includes a non-linear function generator, using novel arrangements of operational amplifiers, to approximate the non-linear operating characteristics which are desired and in one form includes an automatic range changing feature to increase the operating range of the device. |
