Re: Apple IIgs 200w Power Supply

["Henry" <apl2research@comcast.net>]

Are they switchers?  I didn't look at the transistors or the transformer too 
closely.  Must be some really old switching technology because as far as I 
know you need two transformers to make a switcher and the Apple power 
supply's only had one.  I just assumed they were linear.

Thanks for the correction.  I'll have to look further in to their design one 
of these days.


Henry S. Courbis
www.GSE-Reactive.com
Apple II Series Legacy Hardware - Come take a look at what we have to offer!


"Roger Johnstone" <news2006@roger.geek.nz> wrote in message 
20060127115639552+1300@News.Individual.NET">news:20060127115639552+1300@News.Individual.NET...
> In <IoOdnYucBdm-NUXenZ2dnUVZ_tednZ2d@comcast.com> Henry wrote:
>>
>> Okay, math lesson over. ;)  I'm not too sure what you mean by "new 200
>> watt  power supply really heavy power supply?".  If you mean the
>> weight, it  actually weights a little less then the original supplies
>> since it's a  "switching" supply and not "linear".  A switching supply
>> doesn't need a big  heavy transformer like the older supply's do.
>> They convert the AC from 60  cycles to a much higher frequency which
>> is much more efficient way to  convert power.
>
> The Apple II/II+/IIe/IIGS all use switching power supplies, not linear.
> Indeed the use of a switching suply was one of the big advances of the
> original Apple II. I've seen the power supplies used in some S-100
> computers from the late 1970s: huge transformers and big power
> transistors mounted in large metal boxes!
>
> Modern switching supplies are a lot more space-efficient though, mainly
> because they operate at higher frequencies (which allows for smaller
> transformers) and they use much more efficient semiconductors.
>
> -- 
> Roger Johnstone, Invercargill, New Zealand
> http://roger.geek.nz/
> ________________________________________________________________________
>  No Silicon Heaven? Preposterous! Where would all the calculators go?
>
>              Kryten, from the Red Dwarf episode "The Last Day"