13 Jan
2020
13 Jan
'20
7:26 a.m.
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Jon Elson via
cctalk
Sent: 13 January 2020 04:49
To: Stefan Skoglund <stefan.skoglund at agj.net>; General at ezwind.net;
Discussion at ezwind.net:On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: Transformer Fault in a PSU?
On 01/12/2020 10:34 PM, Stefan Skoglund via cctalk wrote:
According to the Technical Description the NE555 is arranged to oscillate at 100KHz, and I
did indeed measure that frequency, when it oscillated.
Regards
Rob
s?n 2020-01-12 klockan 21:10 +0000 skrev Rob
Jarratt via cctalk:
The transformer Rod describes and provided schematic for is
part of a switching power supply,
and not a 50/60 Hz mains transformer. From the picture, it
is almost certainly a ferrite core
transformer running at 25+ KHz.
The PSU in my VAXmate failed recently and I think
I have found a
problem with one of the windings on the transformer not ringing when
I test it with a ringing tester. The technical description of the
VAXmate says that one winding is operated in flyback mode and I
wonder if that has any bearing on the ringing test. Also, one of the
pins appears not to be connected to anything else, so possibly a
broken (melted?) wire.
Can anyone help with the following questions:
The transformer is basically only
intended to provide AC at a specific
voltage while preventing surges and noise from the utility to create
havoc.
What voltage is it specified to provide ? If so, can it be replaced
with maybe a new AC to AC device ?