Motorcycle brake light delay turn-off circuit

(1) Introduction to circuit principle When a fast-moving motorcycle encounters an unexpected situation or needs to turn, it needs to use the foot brake to slow down or stop the vehicle
. Generally, the brake light on a motorcycle will turn on after the foot brake is applied. Reset, the brake light goes out immediately. In this way, it is less likely to attract the attention of vehicles behind you
. If this circuit is installed on a motorcycle, the brake light of the motorcycle can be delayed for a few seconds after the brake is reset like a car light to
remind the vehicles behind to pay attention. This is beneficial to maintaining traffic safety barriers and reducing traffic accidents. has practical significance. The circuit principle is shown in Figure 3-27: Sl is the power
switch, controlled by the car lock, and S2 is the original brake light control switch. Close switch Sl. Because of capacitance C. The voltage at both ends cannot change suddenly. The ② pin of 1C
is at low level, and the brake light H lights up. After a few seconds, because CI is discharged, when the voltage of IC's ② pin is higher than 1.6V, the light H goes out. When the moving
motorcycle encounters a situation and decelerates or stops, switch S2 is closed and C. The short-circuit discharge at both ends causes the ② pin of switch lC to become low level, and the brake
light H is lit immediately. After S2 is reset, H must be delayed for a few seconds before it goes out.
    (2) LC in the component parameter selection circuit is TWH8752,
the maximum allowable current of the high-power switch integrated circuit is 4A, and H is the rear
brake light. Ri is 470k{l. Cl uses 16V, 47tiF electrolytic capacitors
, CZ uses 25V, 2200pF electrolytic capacitors, and VD1 uses
1N5408 rectifier diodes. If you need to change the delay time, you can change
the values ​​of Rl and CL- appropriately.
    (3) The motorcycle brake light delay turn-off circuit is shown in Figure 3-27.