Ground fault interrupter apparatus of the differential transformer type is provided with a sensing amplifier and trip circuit that includes an operational amplifier operated in a manner so that the interrupter apparatus is less sensitive to capacitive ground faults than it is to resistive ground faults. The quality of less sensitivity to capacitive ground faults is preferably obtained by applying to the operational amplifier a biasing voltage that is a half-wave rectified, unfiltered, voltage which aids in maintaining the inputs to the operational amplifier as a pure current source while using only a small number of components that is advantageous for reduced size.

Transient regulation of direct current electrical power supplies

Sensing amplifier and trip circuit particularly for ground fault circuit interrupter

A circuit arrangement for supplying a direct current, which is free from interruptions, from an alternating line current. The circuit includes: a first rectifier which initially rectifies the line current; an energy store, which helps compensate for variations in the rectified voltage; an inverter for chopping up the recitified voltage; a transformer; a second rectifier arrangement; a smoothing filter; and a control device. The voltage which is generated at the output of the smoothing filter is fed to the direct current load. When the voltage across the direct current load falls below a rated value, a first electrical switching device provides an extra current to the direct current load. On the other hand, when the voltage across the direct current load increases above the rated value, a second electrical switching device diverts a portion of the current through the direct current load. In this manner, any changes in the current and voltage across the load are compensated.

Direct curent supply with ribble suppression

A radar transmitter includes a ripple and droop reduction circuit to reduce the ripple and droop of the beam (power) supply. A beam supply filter capacitor is connected to the source of power and an operational amplifier has its balanced input ac connected across the beam supply capacitor. A transistorized amplifier stage inverts the signal from the operational amplifier and amplifies its absolute value up to the same level appearing across the beam supply filter capacitor. A transistorized follower stage is connected to the transistorized amplifier stage for receiving the inverted signal and producing a low impedance output for insertion in series with the beam supply filter capacitor for ripple and droop cancellation. A traveling-wave-tube is connected to the supply power capacitor which receives the ripple and droop free capacitor output and produces substantially consistent pulses for transmission.

Ripple and droop reduction circuit

A ripple eliminating circuit including in series a high power DC source, a capacitor and a negative capacitance circuit having a negative capacitance the absolute value of which is nearly equal to that of said capacitor wherein an output is derived from across the circuit having in series said capacitor and said negative capacitance circuit.

Ripple eliminating circuit

A crystal growing method for growing a crystal from a raw material melt highly magnetic field is being applied to the raw material melt, the electromagnet for applying the magnetic field being supplied with a direct current having a ripple factor of less than 5% to thereby grow a crystal with good crystallinity properties.

Transient regulation of direct current electrical power supplies

Citations

Sensing amplifier and trip circuit particularly for ground fault circuit interrupter

Direct curent supply with ribble suppression

Ripple and droop reduction circuit

Ripple eliminating circuit

Crystal growing method

References

Regulated rectifying apparatus

Regulated power supply having separate regulators responsive to different error signal frequency components