High frequency AC LED lighting system
A circuit having a series interconnection of a light-emitting diode (LED) group, a first transistor, a second transistor and a first resistor. The series interconnection has a cathode coupled to a drain terminal of the first transistor and a source terminal of the first transistor is coupled to a first terminal of the first resistor wherein voltage across the first resistor to provide a biasing voltage for the first transistor. A source terminal of the second transistor is coupled to a first terminal of the first resistor wherein voltage across the second resistor provides a biasing voltage for the second transistor and ancillary circuitry bypasses the series interconnection. The ancillary circuitry has a capacitor to provide current to the series interconnection to increase the amount of light emitted during an electrical excitation cycle.
1. A circuit comprising:
a series interconnection of a light-emitting diode (LED) group, a first transistor, a second transistor and a first resistor, wherein:
the series interconnection has a cathode coupled to a drain terminal of the first transistor and a source terminal of the first transistor is coupled to a first terminal of the first resistor wherein voltage across the first resistor provides a biasing voltage for the first transistor;
a source terminal of the second transistor is coupled to the first terminal of the first resistor wherein voltage across a second resistor provides a biasing voltage for the second transistor; and
ancillary circuitry bypassing the series interconnection and having a capacitor to provide current to the series interconnection to increase the amount of light emitted during an electrical excitation cycle.
2. The circuit according to claim 1 , wherein the capacitor is connected between the drain of an ancillary transistor and a rectifier wherein the ancillary transistor is coupled to a first terminal of an ancillary resistor to provide a biasing voltage for the ancillary transistor.
3. The circuit according to claim 1 , wherein the first and second transistors are depletion MOSFET transistors.
4. The circuit according to claim 1 further comprising a dimmer electrically connected to the series interconnection.
5. The circuit of claim 4 wherein the dimmer is a phase cut dimmer.
6. The circuit of claim 4 wherein the dimmer is configured to provide a relative light output of 5%.