Hi Roy,
You wrote to me:
RJT> GW> In a switching regulator the controlling element is a compound
RJT> GW> of two devices, a transistor, FET or thyristor used as a switch
RJT> GW> and an inductor.
RJT>Except that you can do this sort of thing with no
RJT>inductors,  using capacitors as charge storage devices.
RJT>Look at the ICL7660 (?) chip for an example (I hope I'm
RJT>remembering that number right) or any number of Maxim
RJT>parts,  that are designed to do this on small basis.
You _can_ do it with capacitors (I have, to generate a negative rail for
op-amps in a commercial design  and Intel do (did) to generate
negative rails in their ROMS) but for the systems we're considering in
PCs it'll either be linear or inductive, capacitive versions don't
preovide enough power.
RJT> GW> The variation of the on/off ratio of the switch, in conjunction
RJT> GW> with the inductor is used to control the amount of charge (==
RJT> GW> power) transferred from the supply to the load.
RJT>Aren't there also units which vary the frequency,  rather
RJT>than the pulse width?  I seem to remember both kinds being
RJT>mentioned in the literature.
You can vary the effective on/off ratio either by changing the
frequency or, more often, the mark/space ratio at a fixed frequency.
RJT>This is drifting a bit off the topic here,  but if you like
RJT>we can take it up in the fido ELECTRONICS echo...
Yes, we'd better end the thread now...
Sorry, I don't think the ELECTRONICS echo makes it to Region 25 :-(
George
 * SLMR 2.1a * Wastebasket: Something to throw things near.
--- Maximus/2 3.01
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