16 Mar
2013
16 Mar
'13
3:17 p.m.
Actually, to make this sort of vaguely on-topic, there
may have been
some carry-over from the low-emission/low-power design lessons
learned from those tubes to the design of VFDs.
With the DM160 (or wahtever you call it) as the 'missing link'? The DM160
was a little status indicator tube, in effect a single-segment VFD. It
had a 1.something volt filamnet, a control grid and a phosphor-coated
anode which you eran at about 30V. -3V bias on the grid swould cut it off
and the device would be dark. 0V bias and you'd get a nice green glow from
the anode.
Of course a 3V voltage switng was easy to get from transsitor logic
circuitry and the cotnrol grid took almost no power from the control
circuit. Before there were LEDs, this device was commonmly used as a
logic indicator on digital systems (paper tape equipment, control and
data logging systems, etc). TI was quite small, about 3/16" diameter and 1"
long.
-tony