Switching power supplys or chargers ?

[wkyong]

Can 2 same switching power supplys or chargers (o/p=12Vdc) be connected in series in order to charge a 24Vdc battery?Is blocking diode necessary??
If yes where to place it?

 

[mneary]

If they have the (-12) connected to the earth line, the answer would be no. Also, you need more than 24V (more like 27-28V) to charge a 24V lead-acid battery.

Blocking diode won't help.

 

[wkyong]

If they have the (-12) connected to the earth line, the answer would be no. Also, you need more than 24V (more like 27-28V) to charge a 24V lead-acid battery.

Blocking diode won't help.

Actually I want to ask whether 2 same SMPs can be connected in series or not? Thanks!

 

[Conradb]

I believe that the correct answer is yes and no. Yes if you are not worried about stability and lots of smoke , but NO if the load is capacitive or variable, since the sense feedback circuits in the regulators will fight each other and oscillate since they do not have a real reference, and are using each other as voltage dividers. (you will need to create one, which will waste power!!!) Not practical.

I would not even try connect a small load to series connected SMPS, for this case, one or both would be destroyed by the Battery.