[ARC5] Dumb Question No. 5032

[Kenneth G. Gordon]

On 29 Jul 2017 at 13:19, Robert  Eleazer wrote:

> I have experimented with dynamotors, even rewiring 21 VDC (not a typo) units to work on 12VDC 
> and so forth.
>  
> But the dynamotor regulation question led me to wonder:  Can you run a dynamotor on half wave 
> DC successfully?  
>  
> If I needed yet another high current DC power supply (I have a 50 amp 0-20 VDC unit among 
> others) I have the guts out of one of those big roll-around battery chargers/start carts and I 
> assume it is half wave DC..

If it is fairly modern, it is most probably full-wave center-tap rectified.

My much smaller one is, and I know that many AC arc welders these days also are.

They use very large well-heat-sinked silicon diodes.

My battery charger will output 200 amps for a short time to help start a car, for instance.

I had to open it up to replace the 6 position switch (I used a ceramic tap-switch out of a 
BC-375 tuning unit), and found two stud-mounted diodes on 6" square heavy aluminum 
heat-sinks.

You might open yours up to take a look, but I'll bet I am correct.

Ken W7EKB

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus