A magnetic amplifier voltage-current overload protection circuit

LOW-VOLTAGE, high-current, regulated power supplies, such as are used in transistor computers, present an overload protection problem. In many instances fuses are prohibited because of their susceptibility to damage through vibration or they are unsatisfactory because of other reliability requirements. Circuit breakers may not be placed in the outputs of the regulated supplies because of the regulation they would introduce. Furthermore, from the system standpoint, a protection device in the primary circuit of a number of regulated supplies is desirable so that an overload on any one of the supplies will remove the primary voltage from all the supplies simultaneously. With this circuitry, however, an intolerable overload on one particular supply might cause such a small increase in the total primary currrent that it would be difficult to operate a circuit breaker.