The hands of a switching power supply, the use of 2SC3320 switch, the output is 24V7A, after adding the load will always burn 2SC3320 switch, no load no problem, how is it, there are drawings, that expert help to see, thank you
? 7. Switch tube emission limit current resistance is too small
?????? 8. The switching voltage is damaged
?????? 9. Damage to the rectifier bridge
?????? 10. The insulation between the switch and the heat sink is poor
?????? 11. Switch tube performance or power is too small
?????? 12. B + rectifier diode is damaged
?????? 13. The input AC voltage is too high or too low
Key Positive feedback is too strong to detect C10A, C10B, R14, R101
In general, the main reasons for the damage to the power switch tube are the following 13:
?????? 1. Soft start circuit failure
?????? 2. Switch tube integrated circuit board anti - peak absorption circuit failure
?????? 3. Positive feedback is too strong
?????? 4. Timing capacitor failure leakage
?????? 5. Decoupling Capacitor Failure in Regulating Circuit
?????? 6. The negative feedback loop of the regulator circuit
The power switch works in the switch state, the cause of its damage, in addition to over-current over-voltage, but also taking into account the duty cycle, that is, saturated conduction time and cut-off time ratio.
