Re: Need 12 volt ac to 24 volt ac transformer


"Tim" <tim@xxxxxxx> wrote in message
news:MPG.2099ddfbd4676a8e98975e@xxxxxxxxxxxxxxxxxxxxxx
In article <gxSXh.189$N05.156@xxxxxxxxxxxxxxxxxxxx>,
arfa.daily@xxxxxxxxxxxx says...

<billygoat@xxxxxxxx> wrote in message
news:0ppv235o9mus4s8at62majkluoj0bj79r0@xxxxxxxxxx
On Wed, 25 Apr 2007 21:57:41 GMT, Tim <tim@xxxxxxx> wrote:

In article <k7iv23hqpd7b19oaa8jdkth9aujjrup6rc@xxxxxxx>,
fzabkar@xxxxxxxxxxxxxxxxx says...
On Wed, 25 Apr 2007 14:18:20 GMT, billygoat@xxxxxxxx put finger to
keyboard and composed:

Hi I need to convert 12 volts ac to 24 volts ac for an outdoor
lighting project low amperage, say 500 ma. I am looking for a small
boosting transformer on the cheap. Any suggestions on where I can
find
something like this? Alternately I could use a cheap 12 volt ac to
24
volt dc converter. Google has turned up endless garbage for me.

Thanks


Here's a voltage doubling rectifier:

D1
o-----|--|>|-----|-----o +16V
| _|_ +
12VAC | --- C1
rms | |
o----- )---------+-----o 0V
| _|_ +
| --- C2
| D2 |
|--|<|-----|-----o -16V

The unloaded output voltage is around 33V, but under load you may get
closer to your target.

- Franc Zabkar

OR you could get one of those 220 to 110 travel adaptors and wire the
110 side to 12 VAC and get 24 VAC out the other side.

- Tim -


That sounds the the perfect idea.

Thanks

I rather think not, as the power rating of such an item is highly
unlikely
to be anywhere near the 300 watts or so that you require. At 24 volts,
that
equates to more than 12 amps ...

Arfa



300 Watts? He said 500ma right? 24V x .5A = 12W (roughly)

- Tim -

Indeed. I think I mis-understood his second post where he was talking about
the actual lamps that he intended to use and the - quote - " (300 watt ac
transformer) " I wrongly assumed that as he was talking about 12v and 24v
lamps, and that the 12v ones had a 300 watt transformer to power them, we
must have been talking halogens at 20 or 50 watts apiece. If the (few) 24v
ones only require 500mA, then a transformer-based 'power converter', as you
suggest, would certainly do the job. Sorry for any confusion.

Arfa


.

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