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Bias voltage for SD2942 48V 350W pallet

 
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Bias voltage for SD2942 48V 350W pallet
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fyber
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Post Bias voltage for SD2942 48V 350W pallet Reply with quote
Hi Guys

Does anyone know what the bias voltage should be for the gate of this transistor/pallet board? I know the current is meant to be 200mA MAX but need to work out the voltage

Any help greatly appreciated!
Fri May 01, 2009 1:25 pm View user's profile Send private message
pcs
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Post Reply with quote
It is different for every transistor. You set them to get the current right.

That is why you have trimmer on each board.

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Fri May 01, 2009 3:25 pm View user's profile Send private message Visit poster's website
stylzmovement
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Post Reply with quote
Hi,
Where do you measure the bias voltage or current from ?
Is it the voltage that's important?
Or is it the current?
Mon Feb 24, 2014 6:25 pm View user's profile Send private message
pcs
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Post Reply with quote
It is of course the current.

Now how do you measure current? With current meter of course, make sure drive is disabled.
Start with zero voltage and slowly increase while observing current.

Marko

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Mon Feb 24, 2014 6:41 pm View user's profile Send private message Visit poster's website
stylzmovement
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I have a few more questions,
How do you disable the pallet to perform this test?
Where on the pallet do you measure from?
Is it that the positive probe is placed on the +5 and the negative on the ground
Meter in milli amp mode?
Is that correct?
Mon Feb 24, 2014 6:53 pm View user's profile Send private message
pcs
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Post Reply with quote
There is nothing to disable, just do not apply any RF drive when you do this.

Next connect amp meter in series with power supply and measure away.

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Marko - PCS Electronics
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Tue Feb 25, 2014 12:39 am View user's profile Send private message Visit poster's website
stylzmovement
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Post Reply with quote
2 transistor on an amp module , each one will need to be bias separate?
Tue Feb 25, 2014 2:00 am View user's profile Send private message
pcs
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You have to disconnect drain of the tested fet and connect it separately to power supply via amp meter.

How exactly you can disconnect drain depends on the pallet, most give an option to do that via jumpers or have drains separated anyway.

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Marko - PCS Electronics
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Tue Feb 25, 2014 12:01 pm View user's profile Send private message Visit poster's website
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