TREE

The circuit described below monitors your car's  brake lights, and indicates by a light emiting diode  whether they both function correctly. In that sense, it can save you money by preventing your being fined for driving with defective brake lights, and it also leads to increasing road safety. Circuit diagram : Brake Lights Monitor Circuit Diagram The monitor depends inevitably on the voltage drop across the supply lines to the two lamps. For the circuit to work correctly, that drop needs to be greater than 0.6 V. If this is not so, the drop must be increased by adding a 5 V diode in series with each lamp. Transistor Ti and T2 in figure 1 form a  Schmitt trigger, which reacts to the voltage drop across the supply lines to the two brake lights. This reaction manifests itself in Di lighting via T3. If  one of the brake lights is faulty, the switch-on cur- rent drawn by the other lamp will cause Di to light  briefly when the brake pedal is pressed. If both  brake lights are defec...

The circuit described below monitors your car's brake lights, and indicates by a light emiting diode 12V whether they both function correctly. In that sense, it can save you money by preventing your being fined for driving with defective brake lights, and it also leads to increasing road safety. Car's Brake Lights Monitor Circuit Diagram : The monitor depends inevitably on the voltage drop across the supply lines to the two lamps. For the circuit to work correctly, that drop needs to be greater  than 0.6 V. If this is not so, the drop must be in- creased by adding a 5 V diode in series with each  lamp. Transistor Ti and T2 in figure 1 form a  Schmitt trigger, which reacts to the voltage drop  across the supply lines to the two brake lights. This  reaction manifests itself in Di lighting via T3. If  one of the brake lights is faulty, the switch-on cur- rent drawn by the other lamp will cause Di to light  briefly when the brake pedal is pressed. If both  brake lights are defe...