caution to take; AC input for SMPS/Charger through generator

Thread Starter

Vindhyachal Takniki

Joined Nov 3, 2014
1. We need to install a SMPS based lithium battery chargers 29.2V/15A in a system.

2. System is always powered by generator, which runs around 6 hours a day. Seems a bit old type of generator, we measured its output, it fluctuates between 180-250vac at different loads.
Freq variation is 45-55hz this is not measured but told by user.
Depending upon what kind of load in nearby system, voltage spikes may be high.

3. We opened up earlier system which got damaged, it had two circuits before their SMPS, a voltage correction & a frequency correction system as written on them. they were potted so cannot check what inside it.

4. Now we have to replace system. I think the freq correction is not required, as it is SMPS based & we have to convert ac to dc here.

5. For voltage correction, is there aby ready to use circuit/board which we can use. As we were able to check only for few load types the generator outout, it may fluctaute more.

6. Can we add a freq corection ckt also here?

7. What are the other precuations to take before SMPS?


Joined Feb 20, 2016
A SMPS will generally be immune to frequency variations so I'd not worry about that. As for the voltage, as long as it does not go over volts it will be ok. But add mains filter with some decent varistors to clip the voltage spikes off.