dirt cheap power transformer

[PDRUNEN]

Hi Group,

I am looking for a dirt cheap 60Hz power transfomer (or audio type) to couple a
60Hz signal with isolation over to my electronics which is on the low side.

I am terminating the transformer into a opamp and not using it to power any of
the devices.

I see that teleco 600:600 isolation transformers are also any option but they
appear to be expensive.

The signal I am interested in is more of a full-wave recified AC signal with
amplitude of one volt or less. I want to be able to pass a "copy" of this
signal over to my lowside electronics. I am interested in the peak of the
sine, I don't care if the reproduction is exact as long as it is the same.

Thanks!

Paul

 

[Robert Baer]

Hi Group,

I am looking for a dirt cheap 60Hz power transfomer (or audio type) to couple a
60Hz signal with isolation over to my electronics which is on the low side.

I am terminating the transformer into a opamp and not using it to power any of
the devices.

I see that teleco 600:600 isolation transformers are also any option but they
appear to be expensive.

The signal I am interested in is more of a full-wave recified AC signal with
amplitude of one volt or less. I want to be able to pass a "copy" of this
signal over to my lowside electronics. I am interested in the peak of the
sine, I don't care if the reproduction is exact as long as it is the same.

Thanks!

Paul

Firstly, you say nothing about voltage standoff and/or leakage
requirements, and nothing about input/output signal levels on the xfmr.
In any event, you are incorrect concerning the 600:600 telco xfmrs;
they can be had for a few dollars.
Go to a surplus store and get some small 5 or 10 watt filament
transformers and use them.

 

[Walter Harley]

Hi Group,

I am looking for a dirt cheap 60Hz power transfomer (or audio type) to couple a
60Hz signal with isolation over to my electronics which is on the low side.

[...]

The signal I am interested in is more of a full-wave recified AC signal with
amplitude of one volt or less. I want to be able to pass a "copy" of this
signal over to my lowside electronics. I am interested in the peak of the
sine, I don't care if the reproduction is exact as long as it is the same.

If the signal is rectified, then it is NOT a 60Hz signal any more; it
contains harmonics up to the bandwidth of the rectifying device (possibly
megahertz). If you pass it through a power transformer, you will lose much
of that high-frequency response, and your wave will start looking more like
an unrectified sine wave again.

Also, your rectified signal contains a DC component (that is, the average
value is not 0, unlike the original sine wave); the transformer will filter
out that DC component, so on the secondary side the average value will be 0.

Bottom line is that a power transformer (or any transformer) will NOT give
you an accurate rendition of the input in this situation.

What kind of accuracy do you need?

 

[Tweetldee]

Hi Group,

I am looking for a dirt cheap 60Hz power transfomer (or audio type) to couple a
60Hz signal with isolation over to my electronics which is on the low side.

I am terminating the transformer into a opamp and not using it to power any of
the devices.

I see that teleco 600:600 isolation transformers are also any option but they
appear to be expensive.

The signal I am interested in is more of a full-wave recified AC signal with
amplitude of one volt or less. I want to be able to pass a "copy" of this
signal over to my lowside electronics. I am interested in the peak of the
sine, I don't care if the reproduction is exact as long as it is the same.

Thanks!

Paul

A cheap source for 600:600 audio transformers is in old modems. Go to a
computer store and ask them if they have any old modems that they are going
to throw away. You can probably pick up a handful for a few bucks, and have
enough transformers to let you experiment till the cows come home.

Cheers!!!
--
Dave M
MasonDG44 at comcast dot net (Just subsitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!