HP7475A transformer secondary voltage and power rating ?

[Peter_purple]

Hi chaps,

I'm trying to revitalise an older HP7475A (Hewlett Packard)
desktop A3 plotter and found the power supply input transformer primary
has gone kafffuuuff,

I'm wondering if anyone out there knows what the secondary push-pull
voltage should be so I can insert a substitute, unfortunately there are
no markings on the transformer and the only clue on the main circuit
board is the power supply filtering cap which has a max voltage rating
of 25V,
so I'm wondering if the secondary is 12v or 24v push-pull and the rating

looks like maybe 2 Amps,

Anyone have any ideas ?

Regards

purple engine from perth packed pickled peppers

 

Peter_purple wrote:

Hi chaps,

I'm trying to revitalise an older HP7475A (Hewlett Packard)
desktop A3 plotter and found the power supply input transformer primary
has gone kafffuuuff,

I'm wondering if anyone out there knows what the secondary push-pull
voltage should be so I can insert a substitute, unfortunately there are
no markings on the transformer and the only clue on the main circuit
board is the power supply filtering cap which has a max voltage rating
of 25V,
so I'm wondering if the secondary is 12v or 24v push-pull and the rating

looks like maybe 2 Amps,

Anyone have any ideas ?

Regards

purple engine from perth packed pickled peppers

Output was 12V AC @ 2A. If I remember correctly.

--

David

 

[Peter_purple]

dmmilne@ozemail.com.au wrote:

Peter_purple wrote:


purple engine from perth packed pickled peppers

Output was 12V AC @ 2A. If I remember correctly.

--

David

Ah - yeah that sounds about right, I guess any higher then that and
they would have used a higher voltage electro for headroom, I'll
give it a try over weekend or the kids,

rgds

peter purple no longer perplexed from perth

 

[Peter_purple]

All fixed now,

Turned out to be corroded connections on the transformer lugs !

Now I need to lubricate the bearings and remove spider floss from
the optical encoders... <sigh>

rgds

peter purple from perth



Peter_purple wrote:

dmmilne@ozemail.com.au wrote:

Peter_purple wrote:


purple engine from perth packed pickled peppers

Output was 12V AC @ 2A. If I remember correctly.

--

David

Ah - yeah that sounds about right, I guess any higher then that and
they would have used a higher voltage electro for headroom, I'll
give it a try over weekend or the kids,

rgds

peter purple no longer perplexed from perth