Connect two Ac to Dc adaptors in series

Question

I have a modem with a rating of 10 VDC and 1A but I dont have a adaptor for it. Instead I have two 5VDC and 1A adaptors. Just wanted to know if I connect these adaptors in series would It work ?

Answer 1

This will probably work OK provided that the outputs are both isolated.
ie if both outputs have one side, say -ve, connected to input ground, then they cannot be combined in series. This would be unusual. In most cases the outputs will be fully floating for DC relative to the inputs.

Some supplies will have a capacitor between output (usually negative) and input ground. Usually in the 0.01 - 0.1 uF range. This MAY produce some interesting noise results for circuits that cared but should cause no problem when used as you propose.

Connection is A-ve to B+ve A+ve = 10 VDC +ve out.
B-ve = 10V DC-ve out

In very rare cases it is conceivable that two switching regulators might go into some form of interactive oscillatory mode, but this would be extremely rare if it happened at all.