Phil Wasson wrote:
>
> I thought this would be simple: Design a low cost 15VDC 150ma
> unregulated power supply that will run on 115 or 230 VAC. It must use a
> 2 VA tranformer due to size requirements.
>
> Many companies make a suitable transformer that has two primaries and
> two secondaries. The secondaries are connected in parallel for 15V, 170
> ma output. To switch between 115 and 230 VAC, the primaries are
> connected in either parallel or series. This requires a 3PDT switch.
Nope, see below.
> All the slide switches I can find for this purpose are SPDT or DPDT.
> My question is, how are products designed using a DPDT switch for this
> purpose?
> --
> Phil Wasson
>
> pwasson@pacbell.net
How about this:
L1--+-----------------)||
\ 120 )||
\ +-------)||
\ 120 | 240 ||
\ O__O O ||
\/ | ||
/\ __ | ||
/ O O O ||
/ | ||
/ +-------)||
/ 120 )||
N--+-----------------)||
Gene
Date: Sat, 19 Oct 1996 03:09:45 -0500
Original Subject: Re: 115/230 VAC switching - how do they do it? (I thought it would be easy!)