Abstract: A dimmer switch for an LED light source utilizes a thyristor-type device (“TTD”) having a first terminal, a second terminal, and a gate terminal. A low-voltage power supply converts alternating voltage into a direct voltage and is connected in parallel with the TTD. Gate current supplying circuitry is provided to supply current to the gate of the TTD, the gate current supplying circuitry powered by the low-voltage power supply and including a variable input device operable to vary a voltage waveform at the gate of the TTD in order to vary a voltage waveform provided at the second terminal.

Abstract: A control circuit for controlling current through a load comprises a first terminal for connection to an alternating voltage source, a second terminal for connection to the load and a thyristor-type device having a gate terminal, connected between the first and second terminals. Voltage regulation means is provided for converting alternating voltage into a direct voltage and is connected between the first and second terminals in parallel with the thyristor-type device. Gate current supplying means is provided to supply current to the gate of the thyristor-type device, the gate current supplying means being powered by the voltage regulation means and including a variable input device operable to vary a voltage waveform at the gate of the thyristor-type device in order to vary the voltage waveform provided at the second terminal.