Maximum dissipation question

[crazyjim30]

Determine the maximum dissipation that should be allowed for a 75W silicon transistor rated at 22°C. Derating is required above 22°C by a derating factor of .35 W/°C at a case temp of 142°C. I'm stumped. Not sure where to even start. I'm going to take a smoke break before I throw my computer out of the window. I've been taking a test for 3 hrs.

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[uncle_bob]

Determine the maximum dissipation that should be allowed for a 75W silicon transistor rated at 22°C. Derating is required above 22°C by a derating factor of .35 W/°C at a case temp of 142°C. I'm stumped. Not sure where to even start. I'm going to take a smoke break before I throw my computer out of the window. I've been taking a test for 3 hrs.

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Hi

Look more carefully at the terms. I believe you will find that one of them is not phrased the way you have typed it above.

... hint (spoiler alert ...) ...

It's on the same line as the number 0.35

Bob

[crazyjim30]

Determine the maximum dissipation that should be allowed for a 75W silicon transistor rated at 22°C. Derating is required above 22°C by a derating factor of .35 W/°C at a case temp of 142°C. I'm stumped. Not sure where to even start. I'm going to take a smoke break before I throw my computer out of the window. I've been taking a test for 3 hrs.

Sent from my SM-G900V using Tapatalk

Hi

Look more carefully at the terms. I believe you will find that one of them is not phrased the way you have typed it above.

... hint (spoiler alert ...) ...

It's on the same line as the number 0.35

Bob

Not getting the hint. Sorry. That's the question, word for word. I checked for typos.

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[uncle_bob]

Hi

Ok:

what is the delta temperature between 22 and 143 c?

what is 0.35 times that delta?

what is 75W minus that result?

Bob

[crazyjim30]

*sigh* That was so simple it hurt. Thank you.

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[uncle_bob]

*sigh* That was so simple it hurt. Thank you.

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Hi

Thus the initial hint about the lousy (or deliberately obscure) wording ....

Bob