[Prev][Next][Index][Thread]

Re: rectifying



Hi Reinhard,

	I'm afraid I'm going to have to agree to differ on this 
one:

> Original Poster: "Reinhard Walter Buchner" <rw.buchner-at-verbund-dot-net> 
> 
> Hi Malcom,
> 
> > Original Poster: "Malcolm Watts" <malcolm.watts-at-wnp.ac.nz>
> >
> > Some comments FWIW:
> > I'd strongly advise using the secondary centre-tap with the full wave
> > centre tapped supply just mentioned. It does make use of both half
> > cycles but delivers only half the voltage of the full wave bridge
> > arrangement. Not as efficient since it doesn't deliver any more
> > current.
> 
> I would like to dis-/agree here. You are correct as far as using
> the 4 way rectifier, because you get full voltage (I believe it
> was 3.15kVac, right?), but I canīt agree on, quote "...since it
> doesn't deliver any more current.". That isnīt true :o)) If you
> have a center tapped xformer with 12-0-12 volts (example)
> and each winding sources 1A, then using a cīt-dual diode full
> wave setup WILL deliver more current. Your output would be
> (12*sqrt(2)) volts -at- 2 amps DC making 24+VA. Using a full
> wave bridge, the voltage would be 24V(*sqrt(2) -at-1A or the
> same 24+VA. The total VA doesnīt change. But it DOES
> deliver more current (at half the voltage). The VA (power)
> remains the same, which is what I suspect you wanted to
> say, right?

No. Each diode in the centre tapped arrangement only delivers on 
alternate half cycles. There is no reason why you can't pull the same 
current from either arrangement. However, each winding in the 
centre-tapped supply is being used for only half the time.

Regards,
Malcolm