Ni MyDaq as source for a simple transformer

[student1999]

Hello, I want to use my Ni MyDaq as source for a simple transformer consisting of two coils with N1=300 and N2=400 windings, the wire has a diameter of 0,2 mm.  They are winded around an iron screw with the diameter of 5 mm.

I want to use the analog output of the MyDaq as Input voltage.

I tested the transformer with a function generator and measured as output voltage a fitting sine signal.

But if I use the voltage of the MyDaq the amplitude of the signal drops to a much smaller value.

Is this due to the small output current? I already added an OpAmp (max Output current 20mA) as voltage follower to increase the output current, like it is described in http://forums.ni.com/t5/Educators/myDAQ-tutorial-Increase-analog-output-AO-current-drive-with-op/ta-..., but it did not help me.

It would be nice, if you can confirm or correct my assumption or have any other suggestions, that can help me.

[DMaron]

Hello there,

I think your assumptions are correct. The myDAQ output current is limited to around 2 mA. You could for instance measure the output current of your function generator when driving the transformer with that device. That would give you an idea of which current you need to drive.

Best,

Daniel