Re: Electronics gurus please help

Hi,

It takes 6 power transistors and 6 high speed rectifiers to build a
unipolar "chopper", it takes 8 power transistors and 8 high speed
rectifiers to make a bipolar (full bridge) one.

The power rectifiers are not across the power transistors in the
unipolar drive. If MOSFETs are used in a bipolar drive, the
rectifiers are included in the transistors.

The power transistors "see" twice the power supply voltage in a
unipolar drive. In a bipolar drive, the maximum voltage "seen" by the
power transistors is equal to the supply voltage.

The performance of a unipolar drive is about equal to a bipolar drive
running a motor in a half-winding connection.

A bipolar drive is prefered because it is simpler (when MOSFETs are
used) and the circuit voltages are lower.

Mariss

--- In CAD_CAM_EDM_DRO@y..., Vajk Fekete <vajk.fekete@o...> wrote:
>
> question1: is a chopper unipolar driver much worse than a chopper
bipolar drive?
>