Re: Controller Styles

[ScuderiaEV@aol.com]

In a message dated 15/01/02 00:31:50 GMT Standard Time, bryan@visi.com writes:

> I was looking at the Curtis 1231C and 1221C controller hookup 
>  skimatic and noticed that it looks like it can only power the 
>  motor in one direction.  Are most controllers done this way?  
>  Do any go ahead and implement a proper H-Bridge and allow 
>  bidirectional control?  What other styles are also used?
>  
>  I can understand why they made the controler only unidirectinal.  
>  A full H-Bridge would have 4 times the power silicon in it.

The controllers you mention are designed for motors with series connected 
wound fields. Reversing the polarity of supply to a series wound motor does 
not reverse the direction of rotation. On road vehicles usually do not 
require an instantaneous transition from forwards to reverse, so a momentary 
pause while a contactor switches is no problem. Most conversions utilise the 
gearbox and a mechanical reverse is available.


Paul Compton
www.sciroccoev.co.uk