CIRCUIT FOR INSTANT RESTART OF HIGH PRESSURE DISCHARGE LAMP

• US 3,732,460 A
• Filed: 01/28/1972
• Issued: 05/08/1973
• Est. Priority Date: 01/28/1972
• Status: Expired due to Term

• Current Assignee: Hans L. Wattenbach
• Original Assignee: Hans L. Wattenbach
• Inventors: Wattenbach, Hans L.
• Primary Examiner(s): Kominski, John
• Application Number:
  US05/221,662
• Time in Patent Office: 466 Days
• Field of Search: 315/123,125,126,240,243,247,DIG.2,DIG.5,DIG.7
• US Class Current: 315/123
• CPC Class Codes: H05B 41/042 using semiconductor devices
• CPC Class Codes: Y10S 315/02 High frequency starting operation for fluorescent lamp
• CPC Class Codes: Y10S 315/05 Starting and operating circuit for fluorescent lamp
• CPC Class Codes: Y10S 315/07 Starting and control circuits for gas discharge lamp using transistors

Abstract

In the running condition, a high pressure lamp is connected in series with an inductive reactor across the line (240 volts), and a power factor correcting capacitor is connected across the line. To assure instant starting whether the lamp is hot or cold, an igniter is energized which injects kilovolt radio frequency pulses in series with the reactor open circuit voltage across the lamp, and the reactor open circuit voltage is boosted a predetermined factor up to 3 X line voltage by temporarily connecting the power factor correcting capacitor to a tap in the inductive reactor.

Claims

1. A circuit for operating a high pressure vapor discharge lamp with instant start capability comprising:

a current-limiting inductive reactor for connection to one side of an alternating current supply line in series with the lamp connected to the other side of the line, said reactor having an intermediatE tap therein;

a power factor correcting capacitor;

an igniter for producing kilovolt radio-frequency pulses and including a radio-frequency transformer having an output winding connected in series with said reactor for injecting said pulses superimposed on the reactor open circuit voltage, across the lamp; and

switching means having a starting position wherein said capacitor is connected from the opposite side of the line to the tap in said reactor and a running position wherein said capacitor is connected across the line, said switching means including means to energize said igniter when in the starting position.

2. A circuit as defined in claim 1 wherein the reactor open circuit voltage is boosted by a factor up to 3 when the power-factor correcting capacitor is connected to said tap.

3. A circuit as defined in claim 1 wherein the reactor impedance is proportioned to limit lamp current substantially to its rated value, the power factor correcting capacitor is proportioned substantially to balance the lagging current drawn by the reactor and lamp in the running position, and the tap in said reactor is so located that the reactor open circuit voltage is boosted by a factor up to 3 in the starting condition.

4. A circuit as defined in claim 1 wherein said switching means comprises a mains relay for closing the circuit to the current supply line, said mains relay having a holding loop, switching relays, a timer, and a light integrator, said switching relays being interconnected with said timer whereby they are held in said starting position for a given time interval after the mains relay is energized and then held in said running position, said light integrator being linked with said holding loop to disable said mains relay upon measuring a predetermined time-radiation value.