CET Technology DC/DC converter for VF-Display

[Pszemol]

I am repairing Thermo Orion 525A pH-meter with a VF-Display.

It looks like there is a short in the DC-DC converter module.
The module is made by CET Technologies, model CT-1058.
I am unable to find info about it on their website and they do
not reply to my e-mails asking for help...

It has 7 pins, two for +5V/GND input, two for the 45V output
and three strange pins in the middle showing about 6V on
a working unit but when measured with ohm-meter they show
short (transformer taps?).

I am looking for ideas of buying a replacement DC/DC module
or to make something from scratch which will work similar.
Please advise.

 

[NSM]

It has 7 pins, two for +5V/GND input, two for the 45V output
and three strange pins in the middle showing about 6V on
a working unit but when measured with ohm-meter they show
short (transformer taps?).

Are the 6V pins used? Do they feed separate circuits?

N

 

[Pszemol]

Are the 6V pins used? Do they feed separate circuits?

They look like they are used. There are tracks goning from
these 3 towards the display, but they disappear under it...
There are three separate track going from them.
I was thinking it might be heater for the vacuum display cathode?
I have never repaired a device with VF-Display before, so
I am not sure of the circuit... Do you know any schematic example?
It looks like old, already "fogotten" technology today ;-)

What I am looking for is the place I can get replacement,
or - an idea on how to build similar circuit from discrete
components or other chip from different manufacturer...

 

[Jerry G.]

Go back to their site and get their phone number. Many of these
companies no longer respond to emails unless they specificaly know the
sender. They get too much Spam. When you call have your credit card
handy to place the order (if the module is stillavailabe). Take care,
it is now cheap to replace.


Jerry G.

 

[Bob Urz]

I am repairing Thermo Orion 525A pH-meter with a VF-Display.

It looks like there is a short in the DC-DC converter module.
The module is made by CET Technologies, model CT-1058.
I am unable to find info about it on their website and they do
not reply to my e-mails asking for help...

It has 7 pins, two for +5V/GND input, two for the 45V output
and three strange pins in the middle showing about 6V on
a working unit but when measured with ohm-meter they show
short (transformer taps?).

I am looking for ideas of buying a replacement DC/DC module
or to make something from scratch which will work similar.
Please advise.

If you brave and its not potted, pry the convertor apart and
see if you can trouble shoot it. If its already dead, you
cannot hurt it anymore than it is.

I had one of these displays on a Delco radio once that
had me going. Turned out the tiny glass extension where
they suck the air broke off and let the vacuum out.

Bob

 

[NSM]

They look like they are used. There are tracks goning from
these 3 towards the display, but they disappear under it...
There are three separate track going from them.
I was thinking it might be heater for the vacuum display cathode?
I have never repaired a device with VF-Display before, so
I am not sure of the circuit... Do you know any schematic example?
It looks like old, already "fogotten" technology today ;-)

What I am looking for is the place I can get replacement,
or - an idea on how to build similar circuit from discrete
components or other chip from different manufacturer...

I might be inclined to try to cobble together a regular AC transformer type
supply to keep this going.

http://www.allelectronics.com/cgi-bin/category.cgi?category=200&type=store
has a couple of converters, one of which (CAT# DC-32, "2 for $1") is
somewhat close, but it's either that or a new pH meter.

http://www.alltronics.com/power_sources.htm has some weird crap too (along
with annoying Java pages) but you'll have to poke around there for a while.

N

 

[Pszemol]

If you brave and its not potted, pry the convertor apart and
see if you can trouble shoot it. If its already dead, you
cannot hurt it anymore than it is.

It is potted, so no way to get inside

I had one of these displays on a Delco radio once that
had me going. Turned out the tiny glass extension where
they suck the air broke off and let the vacuum out.

I will double check the display itself.
And maybe replace the module from the good one to be sure.

 

[Pszemol]

Go back to their site and get their phone number. Many of these
companies no longer respond to emails unless they specificaly know the
sender. They get too much Spam. When you call have your credit card
handy to place the order (if the module is stillavailabe). Take care,
it is now cheap to replace.

They responded with delay that this is special module made
for Thermo Orion and I have to contact them for the spare...
I can only imagine how much it will be from there But I will give it a
try.