Patent ID: 8669710

Claim:
An LED module, characterized in that: the LED module comprising: an input terminal; an output terminal; a primary LED; a spare LED; and a switching module, wherein the switching module controls the spare LED to be switched off when the primary LED is switched on, and controls the spare LED to be switched on when the primary LED is burned out; and the switching module has a first field-effect transistor, a second field-effect transistor, a first resistor and a second resistor, wherein the source electrode of the first field-effect transistor is connected to the cathode of the primary LED and connected to ground orderly through the first resistor and the second resistor, the drain electrode thereof is connected to the output terminal, and the gate electrode thereof is connected to ground through the second resistor; the source electrode of the second field-effect transistor is connected to the cathode of the spare LED, the drain electrode thereof is connected to the output terminal, and the gate electrode thereof is connected to the gate electrode of the first field-effect transistor; and the threshold voltage Vth 1 of the first field-effect transistor and the threshold voltage Vth 2 of the second field-effect transistor satisfy the following condition: Vth 1 >−(Vs 1 −Vf)R 1 /(R 1 +R 2 )>Vth 2 >−(Vs 1 −Vf), wherein Vs 1 is an input voltage received by the input terminal, Vf is the forward voltage drop of the primary LED and the spare LED, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor.