in series vs parallel

[Irilia]

My brain got mixed

Can I combine for example a power source of :
30 A+20 A to get 50 A
Or
70 V + 30 V to get 100V

If my memory is right the smallest of  the two power source will be overwork.

[Laval]

If you combine sources in series, you will add voltages. If you combine sources in parallel, assuming they have the same voltage, you will add current. That works with batteries for example. But combining random source together, including batteries, can cause problems in practice. Power supply generally don't work well in parallel, unless they have been designed for that, because their regulation feedback loops may interfere with each other.

It would help to have a bit more context to answer your question.

[Phil1977]

In general: Yes.

You can switch two PS with similar voltage in parallel and get their summed up amperage.
You can switch two PS with similar max. current in series and get their summed up voltage.

But this is only valid for galvanically isolated and current limited supplies. It´s okay (and common use) to do this with laboratory power supplies, but it´s dangerous with nearly everything else.

[Irilia]

Ok so I will do that both of the power source identical, so problem solved 😉
Thanks for your answers.