IR 2110 on 150V dc, GND question

Discussion in 'The Projects Forum' started by Freq50Hz, Feb 12, 2011.

  1. Freq50Hz

    Thread Starter New Member

    Feb 10, 2011
    Hello to everyone, sorry for my spelling in advance.
    This is my first post, so here it goes....

    I am making a half bridge on 150Vdc,

    A.) When I remove the wire witch I marked on the schematics
    the bridge stops to work, is that normal?
    My 15 Vdc power is from an accumulator, and my 150Vdc is from the wall transformer (wall, fuse, transformer, bridge and electrolitic). On data sheet it is specified that the two grounds should not be tied together, but in my case without that connection, the bridge does not show signs of life. It is very confusing! On protoboard everything is cool and running.
    Signals have dead time of 0.3 ms, and
    used freq. is from 1 Hz to 200Hz.

    B.) What do you think, is something missing or I
    should change, any sugestions?

    C.) My control electronics witch use only 30 mA on 15V and are for now on an external source, an acumulator, and I should switch on to that 150Vdc supply. What would be the simplest and most reliable way to get 15V
    from 150Vdc (witch swings from 100Vdc all the way to 150V dc). I am thinking of UC3842, but have never used it before. Any sugestions or schematics?

    Thank you in advance