Capacitor bleed circuit

Claim 2

A capacitor bleed circuit, said capacitor bleed circuit comprising: a capacitor charging circuit and an energy storage capacitor connected thereto to be charged thereby; capacitor charging detecting means connected between said capacitor charging circuit and said energy storage capacitor, said charging detecting means comprising a resistive device said resistive device being a diode, a control resistor connected between said energy storage capacitor and said diode, a detector capacitor connected in parallel to said diode so that said detector capacitor is charged in one polarity during charging of said energy storage capacitor and is charged in the opposite polarity during noncharging of said energy storage capacitor; a capacitor discharge circuit, said capacitor discharge circuit being adapted to be connected in parallel to the energy storage capacitor; said capacitor charging detecting means being connected to said capacitor discharge circuit to turn on said capacitor discharge circuit when said capacitor charging detecting means detects cessation of charging of the energy storage capacitor so that at least a part of the charge on the energy storage capacitor is conducted through said capacitor discharge circuit upon cessation of charging of the energy storage capacitor.

Claim 3

The capacitor bleed circuit of claim 1 wherein a switching device is in said capacitor discharge circuit and said switching device comprises a pair of Darlington connected transistors connected across the diode, and further including a bleed control resistor connected in said capacitor discharge circuit to control current flow therein.

Claim 4

A capacitor charge and discharge circuit comprising: a capacitor charging circuit comprising direct current supply means including a source of alternating current, an unregulated DC bus, rectifier means connected between said alternating current source and said unregulated bus, a regulated bus, capacitor charge control means connected between said unregulated and said regulated bus for controlling the flow of direct current from said unregulated to said regulated bus, said charge control means being controllable to select and limit the maximum voltage on said regulated bus, a second bus connected to said direct current supply means, an energy storage capacitor connected between said regulated bus and said second bus; a first energy storage capacitor discharge circuit connected between said regulated bus and said second bus to substantially completely discharge and absorb the energy of said energy storage capacitor when said first capacitor discharge circuit is actuated; a second energy storage capacitor discharge circuit connected between said regulated bus and said second bus to discharge a portion of the capacitor energy to reduce the voltage on said energy storage capacitor when the voltage on said energy storage capacitor exceeds the peak voltage on said regulated bus, said second capacitor discharge circuit comprising: capacitor charging detecting means connected to said energy storage capacitor for detecting charging of said energy storage capacitor; and a capacitor bleed circuit connected between said regulated and second buses and connected to said detector means so that said bleed circuit is turned on to bleed said capacitor when said detector means detects cessation of charging of said capacitor.

Claim 5

A capacitor charge and discharge circuit comprising: a capacitor charging circuit comprising direct current supply means including a source of alternating current, an unregulated DC bus, rectifier means connected between said alternating current source and said unregulated bus, a regulated bus, capacitor charge control means connected between said unregulated and said regulated bus for controlling the flow of direct current from said unregulated to said regulated bus, said charge control means being controllable to select and limit the maximum voltage on said regulated bus, a second bus connected to said direct current supply means, an energy storage capacitor connected between said regulated bus and said second bus; a first energy storage capacitor discharge circuit connected between said regulated bus and said second bus to substantially completely discharge and absorb the energy of said energy storage capacitor when said first capacitor discharge circuit is actuated; a second energy storage capacitor discharge circuit connected between said regulated bus and said second bus to discharge a portion of the capacitor energy to reduce the voltage on said energy storage capacitor when the voltage on said energy storage capacitor exceeds the peak voltage on said regulated bus, said second capacitor discharge circuit comprising: capacitor charging detecting means connected to said energy storage capacitor for detecting charging of said energy storage capacitor; and a capacitor bleed circuit connected between said regulated and second buses and connected to said detector means so that said bleed circuit is turned on to bleed said capacitor when said detector means detects cessation of charging of said capacitor.