Patent ID: 7336040

Claim:
A single-channel comprehensive protection circuit for a self-excitation half-bridge series resonant circuit having a single-lamp output, comprising a DC block a capacitor C 3 , a first partial pressure resistor R 1 , a second partial pressure resistor R 2 , a rectifying diode D 1 , a filter and integral capacitor C 4 , a release resistor R 3 , a diac D 2 , a filter capacitor C 5 , a filter resistor R 4 , a thyristor SCR, a clamping diode D 3 and a control winding T 1D ; characterized in that one end of the DC block capacitor C 3 is connected with one end of the first partial pressure resistor R 1 , and the other end of the DC block capacitor is connected with a loading point of one end of a fluorescent lamp filament; the other end of the filament is connected with a resonant inductance L; one end of the second partial pressure resistor R 2 is connected with the other end of the first partial pressure resistor R 1 and an anode of the rectifying diode D 1 , and the other end of second partial pressure resistor R 2 is connected with a common ground point; a cathode of the rectifying diode D 1 is connected with one end of the filter and integral capacitor C 4 , one end of the release resistor R 3 , and one end of the diac D 2 , respectively; the other end of the filter and integral capacitor C 4 and the other end of the release resistor R 3 are connected with the common ground point; the other end of diac D 2 is connected with one end of the filter capacitor C 5 , one end of the filter resistor R 4 and a control pole of the thyristor SCR, respectively; the other end of the filter capacitor C 5 , the other end of the filter resistor R 4 , and a cathode of the thyristor SCR are connected with the common ground point; an anode of the thyristor SCR is connected with a cathode of the clamping diode D 3 , and is connected with an end of a power supply end V DC through a resistor R 5 ; an anode of the clamping diode D 3 is connected with one end of the control winding T 1D of an oscillatory coil of a self-excitation half-bridge series resonant circuit; and the other end of the control winding T 1D is connected with the common ground point.