How to achieve two-way voltage regulation output with 2SC8050 boost circuit

se7ens

How to achieve two-way voltage regulation output with 2SC8050 boost circuit [Copy link]

 

This is a boost circuit on a TV high frequency head.

Right input voltage 3.6v

After the transformer and switch 8050, it is converted into two outputs

Since the circuit is completely single-tube self-excited oscillation, it is different from the traditional boost circuit.

Could you please help analyze the working principle of this circuit and tell me the design method of the transformer (frequency, inductance and same-name terminals)?

maychang

Both outputs are unregulated. Each output varies not only with the 3.6V input on the right side, but also with the load.

se7ens

maychang posted on 2021-5-19 18:29 Both outputs are not regulated. Each output changes not only with the 3.6V input on the right side, but also with the load.

How does this circuit realize the switch?

If the oscillation frequency is fixed, it can be understood as an open loop

This also explains why the output is unstable.

maychang

se7ens posted on 2021-5-21 09:18 How does this circuit achieve switching? If the oscillation frequency is fixed, it can be understood as an open loop, which also explains the unstable output

How does this circuit achieve switching?

In the AC path, the collector and base of the transistor are connected to the two ends of the transformer primary, and the transformer primary tap is connected to the emitter on the AC. This constitutes positive feedback. This circuit belongs to the magnetic coupling multi-vibrator circuit. The transformer core must work until it enters saturation. After the core is saturated, the feedback condition is destroyed, and then the circuit flips. A more detailed description cannot be written in the post.