Motor vehicle electronic flasher circuit

The flasher in Figure 1 is mostly used in motorcycles. It has only two pins, "+" and "-", and a buzzer acts as a warning when it is working.

The flasher in Figure 2 is mostly used in diesel vehicles: it has three pins: +24V, ground, and steering switch.

Q2 of these two flashers is easy to damage, so it is recommended to replace it with a medium-power tube such as TIP41C (100V, 6A, 65w). The relay in Figure 2 is also easy to damage (usually the contacts are burned and can be used after polishing). In order to protect Q2 from being broken down by the induced electromotive force of the relay coil, a diode can be added as shown in the figure.