Hardware Hobbyists vs. Emulator Jockeys

Brent Hilpert hilpert at cs.ubc.ca
Thu Jun 18 19:45:25 CDT 2009


blstuart at bellsouth.net wrote:
> 
> >> I've heard a rumour that early 723 data sheets only show it as a
> >> linear
> >> regulator, the designers didn't realise it could be used as a
> >> switcher.
> >> After it started getting used in the latter configuration, example
> >> circuits were added to the data sheet. Does anyone have an early
> >> 723 data
> >> sheet which doesn't show a swtiching regulator circuit?
> >
> >    I have some pretty old NS databooks; I will check.
> 
> I just checked what I have.  My 1977 Voltage Regulator
> Handbook doesn't list it at all. 
>
> My 1980 Linear Databook
> includes a couple of switchers among the typical applications.
> That would suggest such a data sheet would have to be
> around 1978 or 79.

The earliest example I have at hand for the 723 is the manufacturer's schematic
for the Wang 520 calculator. The power supply page with two 723's on it (used
just in linear mode), is dated early 1971. Perhaps the earlier handbook was
from a manufacturer that didn't 2nd-source it.



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