tecMec,

Transformers are AC-only devices. They do not transform DC.

I think what you are looking for is either a rectifer or power supply, a DC/DC converter or perhaps an inverter. No offence, but your post was a little unclear.

The 60V 220A DC - is this the supply you need for your data acquisition system? Are you trying to run it from the mains? Can you verify your figures - 220A is a lot of current for a data acq. system.

Post a bit more info and we can probably help.

-----------------------------------

Start each new day with a smile.

Get it over with.

tx for the reply,
my electrical knowledge is realy bad :)
anyway,
the data acquisition card cannot accept more than 10V

i would like to connect the data acquisition card to the main line, and measure the voltage and current. This can only be done if the signal is conditioned.

i have 48V DC system, (batteries)
and the current running in the main circuit is 200 Amps.

i have seen in some sites DC transducers, i hope they dont mean AC/DC tran. !

So if I'm interpreting your requirement correctly, you want to measure a current of about 200A and connect the measuring transducer into your data acquisition system?

Have a look at the following website:

http://www.lem.com/

LEM have a large range of current sensors for measuring AC and DC currents. Robust, isolated, and fairly cheap. The site takes a bit of navigating, but in the "Products" pulldown list, select "Transducers / Sensors" and you are somewhere near where you need to be.



Hope this helps.

-----------------------------------

Start each new day with a smile.

Get it over with.

tecMec-

Still unclear if you are trying to measure AC or DC, but:

For either AC or DC voltage:
You could use a voltage divider resistor network with appropriate scaling so that the max output is 10V for your maximum main line voltage. Input impedance of data acq (DAQ)cards are pretty high, >1M ohm, so loading effect of the divider may be minimal. Also suggest configuring card properly for you application (single ended, differential, referenced single ended). Read the manual to determine proper setting/wiring.

AC voltage only:
Step down transformer could be used, this would also provide isolation between your line and the DAQ card (see below)

AC or DC current:
1. Use an AC/DC clamp on current probe (i.e. Fluke) with proper current range, provides isolation.

2. Current shunt, no isolation.

AC current:
Toroidal current transformer, also provides isolation.

DC current:
Hall effect transducer, also provides isolation.


Ideally, I always prefer to use isolation (optical or galvanic) between the outside world and the DAQ card- safety and protection insurance (Analog Devices 5B series)

www.ni.com has a lot of resources and technical forums for more info.

Hope this is of assistance.

-Pete

ScottyUK

Hey, thanks for that link, it's in my bookmarks now!

-Pete

Thnx ScottyUK,
Yes u are interpretation is right.
i was looking for a tranducer not a transformer, [i dont know how i wrote that! i got it wrong in the first post :) ]


analogkid2digitalman
nothing is AC , every thing is DC (DC current DC voltage)


Thanx for your reply guys (^_^)