LED driven tail brake Light Cluster
Constant current circuitry 12V Battery operation This circuit was designed on request to drive a Light-cluster formed by several LEDs that can be mounted in the vehicle as a tail and brake light. When SW1 is on, the cluster will illuminate at medium brightness. When brakes are operated, SW2 will be closed and the cluster will shine at maximum brightness. These two brightness levels of the cluster are obtained by a constant current source drive formed by Q1 and Q2. The two constant current levels are set by R2 and R3 values. Circuit diagram : LED driven tail/brake Light Cluster Circuit Diagram Parts : R1___10K 1/4W Resistor R2___33R 1/4W Resistor (See Notes) R3___15R 1/4W Resistor (See Notes) D1___1N5819 40V 1A Schottky-barrier Diode (See Notes) D2--D13___LEDs High brightness, high efficiency red types (See Notes) Q1___BC547 45V 100mA NPN Transistor Q2___BC337 45V 800mA NPN Transistor SW1___SPST Tail Light Switch SW2___SPST Brake Light Switch Notes: The...