Charge regulating circuit for flash lamp storage capacitor

Claim 2

For maintaining a predetermined voltage on a storage capacitor charged from an alternating current power source, a regulating circuit comprising: alternating current input terminals, controlled switch means having current carrying electrodes connected to the alternating current terminals, and a control electrode responsive to a threshold voltage to start and stop charge of the storage capacitor from the alternating current input terminals, a voltage supply connected between the alternating current input terminals and the switch means control electrode, regulating means connected to the voltage supply for controlling application of the threhold voltage from the supply to thE switch means, a controlled electron valve connected to and operative to control the regulating means, and means connected between the storage capacitor and valve responsive to charge of the storage capacitor to said predetermined voltage to operate the valve and stop the regulating means from applying the threhold voltage to the switch means, whereby said switch means, valve and charge responsive means complete a loop regulating the repeated starting and stopping of power supply to the storage capacitor, thereby to hold the charge on the storage capacitor at substantially constant voltage.

Claim 3

A circuit according to claim 1 wherein said regulating means comprises capacitative means, said valve controlling charging of the capacitative means from the voltage supply.

Claim 4

A circuit according to claim 1 wherein said alternating current input terminals are connected through said switch means to an alternating current transformer primary.

Claim 5

A circuit according to claim 1 in combination with an alternating current transformer primary in series with said switch means, and a secondary and rectifying means supplying charging current for the storage capacitor.

Claim 6

A circuit according to claim 4 wherein said responsive means is coupled between the secondary and said electron valve.

Claim 7

A circuit according to claim 5 wherein said responsive means, electron valve, regulating means, switch means and transformer comprise a closed loop.

Claim 8

A circuit according to claim 1 wherein said responsive means comprises a voltage breakdown device.

Claim 9

A circuit according to claim 1 wherein said voltage supply comprises a rectifier bridge having an alternating current input, said regulating means comprising a capacitor connected in parallel with said electron valve across the output of the bridge.

Claim 10

A circuit according to claim 1 wherein the responsive means is coupled to the electron valve by a pulse transformer.

Claim 11

A circuit according to claim 9 wherein the storage capacitor has a discharge circuit and said pulse transformer has a winding adapted to be connected to the discharge circuit and transmit a pulse signal to the electron valve upon discharge of the storage capacitor thereby momentarily disabling the switch means from restarting charge.

Claim 12

A circuit according to claim 10 in combination with a storage capacitor and a gas discharge device therefor.

Claim 13

A circuit according to claim 11 wherein said gas discharge device is a flash lamp.

Claim 14

A charge-discharge circuit comprising a gas discharge flash lamp (FT), a storage capacitor (C5) having a discharge circuit through the lamp, a power supply including an alternating current transformer (TI) having a primary (T1'') and secondary (T1''''), a rectifier (D1, D2) connected to the secondary, and a direct current charging connection between the rectifier and storage capacitor, a gas discharge breakdown device (NE1) and a series potentiometer (R2) in parallel with the storage capacitor, said device discharging at a voltage fraction of the charging direct current selected by the potentiometer, alternating current terminals (A,C), a controlled electronic switch (Q2) connecting the power transformer primary across the alternating current terminals, said controlled switch having a direct current threshold closing voltage and a breakdown silicon switch (Q1) for applying the threshold voltage thereto, closing of said switch starting charge of the storage capacitor, a rectifier bridge (D4-D7) between the alternating current terminals, a first regulating capacitance (C1) across the bridge and connected to the silicon switch for storing the threshold voltage, a second regulating capacitance (C2) across the bridge storing an enabling charge for the controlled switch (Q2), a controlled electronic valve (Q3) for discharging the second regulating capacitor, and a pulse transformer (T2) coupling the gas discharge breakdown deVice (NE1) to the electronic valve, breakdown of the device operating the valve to discharge the second regulating capacitance, disable the controlled switch (Q2), disconnect the power transformer primary (T1'') and stop charging of the storage capacitors at a voltage selected by the potentiometer (R2), thereby to hold the charge on the storage capacitor at substantially constant voltage.

Claim 15

A charge-discharge circuit comprising a gas discharge flash lamp (FT), a storage capacitor (C5) having a discharge circuit through the lamp, a power supply including an alternating current transformer (TI) having a primary (T1'') and secondary (T1''''), a rectifier (D1, D2) connected to the secondary, and a direct current charging connection between the rectifier and storage capacitor, a gas discharge breakdown device (NE1) and a series potentiometer (R2) in parallel with the storage capacitor, said device discharging at a voltage fraction of the charging direct current selected by the potentiometer, alternating current terminals (A,C), a controlled electronic switch (Q2) connecting the power transformer primary across the alternating current terminals, said controlled switch having a direct current threshold closing voltage and a breakdown silicon switch (Q1) for applying the threshold voltage thereto, closing of said switch starting charge of the storage capacitor, a rectifier bridge (D4-D7) between the alternating current terminals, a first regulating capacitance (C1) across the bridge and connected to the silicon switch for storing the threshold voltage, a second regulating capacitance (C2) across the bridge storing an enabling charge for the controlled switch (Q2), a controlled electronic valve (Q3) for discharging the second regulating capacitor, and a pulse transformer (T2) coupling the gas discharge breakdown deVice (NE1) to the electronic valve, breakdown of the device operating the valve to discharge the second regulating capacitance, disable the controlled switch (Q2), disconnect the power transformer primary (T1'') and stop charging of the storage capacitors at a voltage selected by the potentiometer (R2), thereby to hold the charge on the storage capacitor at substantially constant voltage.