Hello all.
I have a FUSION fp1402 with blown power mosfet's.
The originals are FQP50N06. 50A - 60V N channel.
The drive ic is TL494CN (if that's what it's called)
I am having a lot or trouble finding some replacement's in australia, SO I thought I might see if I can use a substitute....
Anyone know of another mosfet I can use in place of the original.??
(fqp50n06)
I did some searching and all I could find is ifrz44n may work, But I have no idea so I thought I'd ask.
Greatly appreciate you're help!.
I have a FUSION fp1402 with blown power mosfet's.
The originals are FQP50N06. 50A - 60V N channel.
The drive ic is TL494CN (if that's what it's called)
I am having a lot or trouble finding some replacement's in australia, SO I thought I might see if I can use a substitute....
Anyone know of another mosfet I can use in place of the original.??
(fqp50n06)
I did some searching and all I could find is ifrz44n may work, But I have no idea so I thought I'd ask.
Greatly appreciate you're help!.
Yes. The voltage that the FETs will have to withstand is about 2x the supply voltage which will never be more than about 15v so they'll never see more than 30v.
Farnell have them in stock
FQP50N06 - FAIRCHILD SEMICONDUCTOR - MOSFET, N, TO-220 | element14 Australia
FQP50N06 - FAIRCHILD SEMICONDUCTOR - MOSFET, N, TO-220 | element14 Australia
petercourt, if you still haven't found your fets mouser.com has a Fairchild
FDP80N06 Thats 80A @ 60v. for $1.68 each.
wadest
FDP80N06 Thats 80A @ 60v. for $1.68 each.
wadest
sub mosfet
petercourt, I would recomend you use Mosfets of 60 volts or higher. Sometimes at high current you can get spilkes much higher than three times the input voltage.
wadest
petercourt, I would recomend you use Mosfets of 60 volts or higher. Sometimes at high current you can get spilkes much higher than three times the input voltage.
wadest
Thankyou wadest.
Bit of a late reply, only just noticed your reply.
I already had the 44's on order before your post.
I installed them, amp works great now, though running hot.
Gets far too hot to touch the amp.
So i can now see your concern.
I can only assume that the hotter conditions are due to the mosfets being a tiny bit under-spec.
Amp runs great as of right now, but i am a bit concerned about another falure so i think i might re-order something a bit more suited.
Mainly would like to update my progress of this repair for anyone else that might find themselvs in the same boat.
Irfz44s will work, but only just.(well thats what i found in this instance)
But i guess you have to expect this, it is a subsitute after all.
With thanx to this forum, thats 1 sucsessfull repair out of the way and now im now onto another repair.
Thanx guys.
Bit of a late reply, only just noticed your reply.
I already had the 44's on order before your post.
I installed them, amp works great now, though running hot.
Gets far too hot to touch the amp.
So i can now see your concern.
I can only assume that the hotter conditions are due to the mosfets being a tiny bit under-spec.
Amp runs great as of right now, but i am a bit concerned about another falure so i think i might re-order something a bit more suited.
Mainly would like to update my progress of this repair for anyone else that might find themselvs in the same boat.
Irfz44s will work, but only just.(well thats what i found in this instance)
But i guess you have to expect this, it is a subsitute after all.
With thanx to this forum, thats 1 sucsessfull repair out of the way and now im now onto another repair.
Thanx guys.
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petercourt, I have one question. Is the power supply getting hot or the area where the amplifiers are? If its the power supply thats getting hot it could be the FET's. The IRFZ44 has an RDSon of 28 milliohms, the FDP80N06 has an RDSon of 8.5 milliohms. So the IRFZ44's will produce over three times the dissipation than the FDP80N06 will. Thats over three times hotter.
Wade Stewart
I've used IRFZ44N'S in place of the FQP50N06'S for years in many different amps and have never had a problem with them nor a heat issue ..
You might want to check for leaky power supply drivers or out of tolorance gate resistors also check the outputs for leaky ones..
You may want to check out the amp some more for defective parts ..
Or if it's the output section of the amp running hot u may have to low of an impedance on the amp
You might want to check for leaky power supply drivers or out of tolorance gate resistors also check the outputs for leaky ones..
You may want to check out the amp some more for defective parts ..
Or if it's the output section of the amp running hot u may have to low of an impedance on the amp
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petercourt, S Merlington may be correct. Thats one of the reasons I asked where the heat was coming from. If you have a scope connect it between battery ground and one of the primary winding of the trransformer if you have a large spike when the FET'a switch phase then you might have cross conduction. Thats where both FET's are on at the same time. Probably because the Gates are turning off too slow. Another thing to try is look at the battery current at idle. Lt me know what you find out.
Wade
Wade
The 44's that i replaced are getting hot, they get hot under high power.
As i understand, hot is normal, though they seem to be getting too hot.
I have not checked any other components.
Output section heat wise seems ok.
I dont have a scope, so i am unable to check things in further detail.
Amp is running 2x 4ohm speakers stereo.
Ill check the idle current today and let you know.
As i understand, hot is normal, though they seem to be getting too hot.
I have not checked any other components.
Output section heat wise seems ok.
I dont have a scope, so i am unable to check things in further detail.
Amp is running 2x 4ohm speakers stereo.
Ill check the idle current today and let you know.
If you think that there is a problem, post the DC voltage on pins 9 and 10 of IC301 and on the emitter terminals of Q1 and Q2.
overheating
petercourt, .64 A is fine. I see where you said that the supply doesn't heat up at idle. It sounds to me that you have no power supply problem. Typically both the FET's and output transistors can reach 80 deg C or higher before you have a potential problem. Thats 176 deg. F.
Wade
petercourt, .64 A is fine. I see where you said that the supply doesn't heat up at idle. It sounds to me that you have no power supply problem. Typically both the FET's and output transistors can reach 80 deg C or higher before you have a potential problem. Thats 176 deg. F.
Wade
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