28 Aug
2006
28 Aug
'06
8:30 p.m.
M H Stein wrote:
The TNT uses:
26VAC (180mA) on pins 1&3
20VDC (50mA) on pin 2
GND on pin 4
The PSS uses:
19VAC (750mA) on pins 1&3
20VDC (150mA) on pin 2
GND on pin 4
The similarity is suggestive. I.e. perhaps a lossy
transformer that, when loaded more heavily in the PSS
(4X the current requirements) sags from the lightly
loaded "26VAC" spec for the TNT to the "19VAC" spec
for the PSS.
Yeah, I know, "wishful thinking" but hard to come to any
better conclusion without *seeing* the bricks in question.
It is also conceivable that the 26VAC was deliberately
lowered to 19VAC to reduce power dissipation in whatever
on-board power conditioning circuitry is used in the PSS
(since that extra ~0.5A would aggravate any linear
regulator design therein).
From: Don
<THX1138 at dakotacom.net>
Subject: Votrax TNT, PSS, et al. "bricks"
Has anyone reverse engineered any of these products
requiring *external* power supplies (bricks)? E.g.,
*not* the VS6.x devices but, rather, the "consumer-ish"
devices mentioned in the subject line?
Coincidentally, I've got a VSS on the desk in front of me
without a PS and was just investigating the same thing.
There was a post here a while back very helpfully listing
the pins & voltages (20VDC & 28VAC IIRC); I believe it also
said that the PSs were _not_ the same for various different
models.
Let me know what you find pls.