초록 ▼

A circuit for suppressing surge or transient currents between a DC power supply and a capacitive load includes a suppression impedance of relatively high impedance connected in series with the load between the DC supply and load, a transistorized control circuit for sensing the voltage across the lo

A circuit for suppressing surge or transient currents between a DC power supply and a capacitive load includes a suppression impedance of relatively high impedance connected in series with the load between the DC supply and load, a transistorized control circuit for sensing the voltage across the load, and producing a firing signal when the level of voltage exceeds a predetermined level, and an SCR having its main current path connected in parallel with the suppression impedance, and its gate electrode receptive of the firing signal for turning on the SCR to by-pass the suppression impedance subsequent to application of power to the load.

대표청구항 ▼

A dual DC voltage power supply providing positive and negative DC voltages including soft turn-on circuitry to limit inrush current to substantially uncharged capacitive loads, said power supply comprising: a plurality of rectifier circuits providing at least one positive DC voltage level and at lea

A dual DC voltage power supply providing positive and negative DC voltages including soft turn-on circuitry to limit inrush current to substantially uncharged capacitive loads, said power supply comprising: a plurality of rectifier circuits providing at least one positive DC voltage level and at least one negative DC voltage level from at least one AC input voltage; a plurality of power terminals for receiving said rectified voltage; an output terminal for each said DC voltage level; a reference terminal for connection to a point of reference potential; control means for each said DC voltage level, said control means being coupled in parallel relation with said capacitive load and responsive to the voltage developed across said load attaining a predetermined value whereupon said control means provides a firing signal; turn-on current suppression means for each DC voltage level, said suppression means having a relatively high impedance connected between one of said power terminals and said output terminal, wherein said impedance limits the magnitude of current supplied to said load in the absence of said control firing signal; and switching means having a main current conduction path coupled in parallel with each said suppression impedance, said switching means being responsive to said control firing signal to provide a low impedance by-pass across said suppression impedance.