Switching power supply output voltage is too low
In addition to the voltage regulator control circuit will cause the output voltage to be low, there are the following reasons for the output voltage to be low:
1. The load of the switching power supply has a short-circuit fault (especially the DC/DC converter is short-circuited or has poor performance, etc.), at this time, all loads of the switching power supply circuit should be disconnected to distinguish whether the switching power supply circuit or the load circuit is faulty. If the voltage output of the disconnected load circuit is normal, it means that the load is too heavy; or if it is still abnormal, it means that the switching power supply circuit is faulty.
2. The failure of the rectifier diode and filter capacitor at the output voltage end can be judged by the substitution method.
3. The performance of the switch tube decreases, which will inevitably lead to the failure of the switch tube to conduct normally, which increases the internal resistance of the power supply and reduces the load capacity.
