18 watt jtm / 18 watt Lite II

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mehfuzhoss
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Re: 18 watt jtm / 18 watt Lite II

Post by mehfuzhoss »

these mosfets are 400V mouser part: 78-IRF740BPBF
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geoff 1965
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Re: 18 watt jtm / 18 watt Lite II

Post by geoff 1965 »

Try and post the mosfet spec sheet rather than the mouser part No.
I know they are a pain in the butt to source the correct type! i.e. the Toshiba ones I used are now obsolete and the NTE2377’s are over £15 each here in the UK.
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mehfuzhoss
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Re: 18 watt jtm / 18 watt Lite II

Post by mehfuzhoss »

spec pdf attached
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geoff 1965
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Re: 18 watt jtm / 18 watt Lite II

Post by geoff 1965 »

The voltage and power dissipation look okay,you don’t want less than 600V especially if your going to use the 290paz with higher B+ and you have to take into account voltage surge when powering on which will be a lot higher than your stable B+ voltage.okay so get the spec sheet for the NTE2377 or NTE2973 and compare to see if it’s the same type.
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mehfuzhoss
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Re: 18 watt jtm / 18 watt Lite II

Post by mehfuzhoss »

not same but very similar in specification comparison.

Drain source voltage is 600V and 297x upto 900v
Power dissipation is low at @180Watt whereas 297x has 250watt
input/output capacitance is 1350/70 pf whereas 297x input/output capacitance is: 2900/290 pf

so power dissipation and I/0 capacitance has a lots of gap.
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