Re: ATM 12 V AC Power supply for Camtrak ??

[Dwight Elvey <elvey@hal.com>]

Sofjan@aol.com wrote:
---snip---
>     I wonder if the Inverter that sold by auto part store or department store
> will give a 60 Hz 110volt ac.  I need an advice here.

Hi
Most of these small ones are designed to be 60 Hz to within about 1% - 3%.
Most use RC time constants. They used to use various transformer
oscillators that didn't have good frequency control. Most
of the newer ones have a high frequency transformer to make
110 volts DC and then chop this with an H bridge output.
The control is usually done with some RC network and a
timer chip, like the 555. It is possible to make these into
slewing and fine controls but be most careful, you might
survive 110V AC but 110 DC won't let you let go until
your muscle is dead. Across your chest would not be good!
 Try it with your 12 volt transformer, it should work
about as well as the original wall power.
Dwight