Switching power supplys or chargers ?

Discussion in 'General Electronics Chat' started by wkyong, May 1, 2008.

  1. wkyong

    Thread Starter Active Member

    Apr 29, 2008
    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?
  2. mik3

    Senior Member

    Feb 4, 2008
    if the SMPU's have isolated outputs you can connect them in series and you dont need any diodes. Otherwise you cant connect them.
  3. Papabravo


    Feb 24, 2006
    I don't think you can do this at all. If the supply is designed to output 12V it will be with respect to some reference. Depending on the topology of the supply the input may be above or below 12V. In the case of an isolated switching supply connected in series there will be three different ground references.

    1. Input 1 Ground
    2. Output 1/Input 2 Ground
    3. Output 2 Ground.
    With respect to Output 2 Ground the ouput volatage will be...ta da...12 Volts. Regardless of the value of Input 1 with respect to Input 1 Ground.