[Amps] PSU design question

[Roger]

> One caution however: there is no protection for the meter if there is an arc and
> the current rises to a large value. The meter could be destroyed. The best way
> to protect the meter is to use a pair of heavy duty diodes such as the 6A10,
> connected in anti-parallel (back to back with reverse polarity) 
>   
Why? It's DC. Wouldn't one diode should suffice?  We used two of 
opposite polarity in parallel with AC at work.
> 73, Bill W6WRT
>   
73

Roger (K8RI)