Discharge lamp energization circuit, particularly for audio and supersonic frequency operation of high-pressure discharge lamps

Discharge lamp energization circuit to energize a lamp (1) with alternating current at a frequency high with respect to power line frequency (50, 60 Hz) having

• an inductance (2) serially connected to a terminal (7) of the lamp (1) and forming a series circuit therewith, and means (3) supplying a d-c voltage to operate the lamp,
• and comprising, in accordance with the invention,
• two capacitors (4, 5) of equal capacity value, serially connected across the d-c voltage supply (3), the series circuit of the inductance (2) and the lamp (1) being connected to the junction (6) of the serially connected capacitors;
• a first electronically controlled switch (10) connected to the free terminal (8) of one capacitor (4);
• a second electronically controlled switch (11) connected to the free terminal (9) of the other capacitor (5),
• said switches being connected to the other lamp terminal (12) forming the free terminal of the series circuit;
• and a timing control circuit (15) connected to and controlling both said switches to be alternately conductive,
• the timing control circuit providing a frequency-stable output control signal to said switches at a frequency matched to a certain operating frequency of the lamp (1) and controlling the electronically controlled switches to essentially instantaneous conduction and cut-off, respectively, and providing an essentially square-wave voltage to said electronically controlled switches at said frequency matched to the lamp operating frequency, and thus supplying a-c square-wave voltage to the lamp circuit.