Led driving circuit

An LED driving circuit comprising:

• a serially connected LED circuit, in which n pieces of LED devices having forward voltage Vf respectively are serially connected;
• and
• a switching device serially connected with the serially connected LED circuit to control that an electrical current flowing through the serially connected LED circuit is turned on or off;
• wherein the LED driving circuit further comprises:
• a DC power supply, in which power supply voltage Vcc is, Vcc>Vf×n;
• a circuit device connected in parallel with the switching device to make a minute current flow through the serially connected LED circuit to the extent that the LED devices are not turned on when the switching device is turned off;
• and
• the switching device, in which applicable maximum voltage VCEO is, VCEO<Vcc.

An LED driving circuit comprising:

• a serially connected LED circuit, in which many LED devices are serially connected;
• a first switching device serially connected with the serially connected LED circuit to control an electrical current flowing through the serially connected LED circuit;
• a current setting resistor circuit, which comprises a plural of resistors connected in parallel with each other between the first switching device and a ground terminal, and second switching devices, each of which is serially connected with each of the plural of resistors;
• and
• a setting circuit for setting on or off of the second switching devices respectively.

An LED driving circuit comprising:

• a serially connected LED circuit, in which many LED devices are serially connected;
• and
• a first switching device serially connected with the serially connected LED circuit to control an electrical current flowing through the serially connected LED circuit;
• and
• a fuse device serially connected with the serially connected LED circuit and the first switching device.

An LED driving circuit comprising:

• a serially connected LED circuit, in which many LED devices are serially connected;
• a first switching device serially connected with the serially connected LED circuit to control an electrical current flowing through the serially connected LED circuit;
• and
• a diode device connected in parallel with the serially connected LED circuit.

An LED driving circuit comprising:

• a serially connected LED circuit, in which many LED devices are serially connected;
• a first switching device serially connected with the serially connected LED circuit to control an electrical current flowing through the serially connected LED circuit;
• a switching device cascade connected with the first switching device, the switching device connected between the serially connected LED circuit and the first switching device;
• a current setting resistor device connected between the first switching device and a ground terminal;
• a buffer amplifier connected with a base terminal of the first switching device;
• a multiplexer connected with an input of the buffer amplifier to switch LED on signal and off signal;
• and
• a lighting time control circuit to form times of the LED on signal and off signal.

An LED driving circuit comprising:

• a serially connected LED circuit, in which many LED devices are serially connected;
• a first switching device serially connected with the serially connected LED circuit to control an electrical current flowing through the serially connected LED circuit;
• a current setting resistor device connected between the first switching device and a ground terminal;
• and
• a condenser device connected in parallel with the current setting resistor device.