Color changing flash light principle circuit diagram

The collectors of the two transistors of the multivibrator are connected to light-emitting tubes respectively, and the light-emitting tubes can flash alternately according to the period of the multivibrator. This circuit has a wide range of uses and can be used for home decoration, etc.!

How the circuit works

This circuit uses high-gain pnp type germanium tubes vt3 and vt4 to form a multivibrator. There are two stages of inverters connected end to end. Capacitors c3 and c4 are used to couple the stages. Its working period is 1s!

Component selection and debugging

The transistor should choose 9012 or 9015 with a collector current greater than 50ma, and the light-emitting tube should choose a tube with high brightness!

If you want to change the flashing speed, you can adjust the capacity of c3 and c4, or you can use fine adjustment to replace r3 and r4. After the strips are set, replace them with the corresponding resistors!