3 Mar
2008
3 Mar
'08
1:21 p.m.
Ethan Dicks wrote:
On Sat, Mar 01, 2008 at 08:54:10PM -0800, Brent Hilpert wrote:
No, I didn't mean to suggest that you would want to re-implement one of the
Heathkit designs/apps, just that the Heath schematics might be available and
might provide some circuit examples/hints of biasing techniques, drivers, & c.
(not always included on spec sheets).
e.g.: As it turns out, I have the schematic for the GC-1092 clock here (don't
have the clock, just the schematic, which has been hanging around in my files
since the 70's). It uses SP-352 displays, and shows the keep-alive cathode and
supply, etc.
Don't know why that web page refers to the Sperry/Beckman displays as Panaplex,
my understanding was Panaplex was a Burroughs trade name for their 7-seg
gas-discharge displays.
Ethan Dicks wrote:
Oh, yeah. I even have one of those 6-digit Heathkit clocks. Still, the
trick with those is that some of the Sperry/Beckman displays have keep-
alive-anodes, and some do not. From the one link that was recently
posted, it's clear that there was a large variety of displays made back
in the day, and you could select a display for your requirements (especially
how many primary anodes for multiplexing).
In this case, I have a particular display, one of the more complex ones,
looking for an application; not the other way around. > > There is a vendor and part number
etched on the face: Sperry SP-738.
Forgot before, Heathkit used those Sperry/Beckman displays in their 70's-era
digital doodads like clocks, indoor-outdoor thermometers, weather monitors,
tachs, & c., might be a place to look for schematics for examples of real-world use.