rectifying NST at half the output

Discussion in 'General Electronics Chat' started by electricmaniac, Mar 23, 2013.

  1. electricmaniac

    Thread Starter New Member

    Jul 25, 2011
    I’m currently working with a neon sign transformer whose specs are as follow: input 220-230V @50Hz, output 1000VAC – 25/30mA. Now, I need to make the transformer work only at half the output i.e. 500VDC but I don’t know how to do this and how to rectify the output accordingly.

    On the transformer’s plate I read this: secondary 500V-E-500V, which makes me think that there is a center-tap (E) that would enable me to use only one of the two windings to obtain half the voltage. Therefore I wolud conncet one (hot) terminal to one side of a full-wave bridge rectifier (4 diodes) and the center-tap (E) to the other side of the bridge. I’m not sure of this scheme, given that the ground terminal should be connected to the ground circuit of the line feeding the transformer’s primary (I’ll use a variac).

    Is there any better solution? Moreover, I don’t know if a full-wave bridge rectifier would be a good idea with this configuration (the primary purpose is to charge a capacitor)…

    Thank you!