150W MOSFET Amplifier with IRFP250x2

[apexaudio]

Sir Mile can i use this Protect from AX14 to FH9 Sir thank you so juch sir

Yes

 

[desertstorm]

thank you sir Mile

 

[desertstorm]

Yes

Like this Sir Mile please correct me if im mistake Sir thank you so much sir

 

[andrewlebon]

R5/R6 10 OHMS 1/4 watt is sufficient will work like a fuse not 1 watt.

warm regards
Andrew

 

[desertstorm]

thank sir Andrew to your comments i will replace it thanks

 

[ballisticz4]

Hey all. Im having some issues with my build, and hoping you guys could offer some advice. First used the dim bulb tsetser and all was good, bulb dimmed a sec after switching on. Then proceeded to bias the amps, but could not bias it. Got between 0 and 1mv turning pot either way trying to bias it. Also getting 18vdc on the output. I would appreciate any advice on this problem please. Thank you

 

[ballisticz4]

can IRFP150 be used in place of IRFP250, if it can, are there any other changes that need to be made

 

[ballisticz4]

Checked everything again, and all was fine. Still couldnt bias amp and high dc output. Then the smoke came from 220r resistor leading to IRFP250. Please help

 

[thimios]

Checked everything again, and all was fine. Still couldnt bias amp and high dc output. Then the smoke came from 220r resistor leading to IRFP250. Please help

Make sure that you have wire the amplifier according with this?

 

[ballisticz4]

I did, thats when the resistor started burning. Will have another look later tonight and see. Thank You Thimios. Oh, would you know if I can use IRFP150 in place of IRFP250?

 

[Bruce@bluff]

Do you access to an oscilloscope? it sounds like your amp could be oscillating a current limited power supply would also be handy

 

[thimios]

Make sure that you have connect the input GND to the power supply 0V,like on the schematic that i have posted.

 

[kandimba]

Hi M. Mile your MM4 tested, with an old belt drive TEAC MM cartridge. Sound is very nice.

Pozdrav

 

[thimios]

Nice!
Can you share the pcb pdf or jpeg?
I mean in black&white for home etching.

 

[jxdking]

I am looking at the bias control portion, at 1st post of this thread.
The maximin output current is controlled by BF871, and the current is limited to 1 Vbe / 0.22 Ohm, which is less than 4A. I don't think you can get "+/-50V DC give 150W on 4R load". Maybe I missed something.

 

[kandimba]

Nice!
Can you share the pcb pdf or jpeg?
I mean in black&white for home etching.

Hi Thimios, here you have your pcb MM4 for home etching.

Regards

 

[desertstorm]

Yes

Sir Mile can i use IRFP240 instead of IRFP250 in NX400 Sir thank you sir

 

[apexaudio]

Sir Mile can i use IRFP240 instead of IRFP250 in NX400 Sir thank you sir

Yes

 

[desertstorm]

thank you so much sir Mile

 

[apexaudio]

N20 made by Igor Santana