The Joyce PSU is something like the early Mac
ones--basically run off
the flyback transformer for the CRT. Very, very little excess
I disagree. The PSU is on the same PCB as the monitor, but in nrither case
does any of the logic run off the flyback transformer.
I have the Amstrad PCW8256 service manual here. The PSU is a switch-mode
thing using an STK7308 hybrid chip. It produces +5V, +12V, +24V.
The monitor is a conventional monochrome design running off that +12V
line. The CRT heater is powered straight from that, other CRT voltages
come from the flyback transformer as you'd expect.
capacity--indeed, if you're printing, the display
goes a bit wonky.
Thati s a separae issue. I can well beleive the decoupling is not all it
should be :-)
It's not what I'd call a desirable setup. And
Cthulhu help you if
you accidentally overload or short a power supply output--there are a
How is the average user going to do that?
bunch of circuit protectors in TO-92 packages soldered
onto the video
board. I'd never seen one on this side of the Pond before, and it
They are very common in consumer electronics over here. And not hard to
get. I am sure a UK supplier will ship across the Pond.
Now perhaps you know how I feel when I want to get 0.125" or 0.156" edge
connectors (which nobody stocks over here). And UNC bolts are rarer than
rocking horse manure in the UK. Much rarer.
took awhile before I tumbled to what they were. I
just replaced the
blown ones with picofuses.
That's what a lot of people do :-). According to the manual, there are 3
of them, one inseries with each chopper transformer secondary winding.
They're ICP-N75 devices, which I think are 3A. But I would have to check.
-tony