UCD 25 watts to 1200 watts using 2 mosfets

This is my PCB with Laci's change on LM311 part. This board can take TO220 and TO247 fets. Also has DC protection, turn on and off speaker with delay, clip and signal indicator. Also has temperature protection (80 deegres) with sensor KTY81-122 (conection 1 and 2) for output coil or hetsink.

Protection is with 24V 30A relay. AC conector is for ACvoltage from transformer for turn on and of speaker with delay

Fets are under PCB. Under PCB are wires from leds to 10pin conector. TIP41c has his own heatsink and "big" resistor are in vertical position.

Output coil is on conector 5mm 40A (filter) in the air one inch above PCB

Dimension are 8.5cm x 10.5cm
 

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I've received my boards , they look great for me .
I´ll need time xD to build them.

regards!

ty ejtagle!
hope it works, build and test and report back

I´m testing it at 25vdc with irfp460(i just have a bunch of them).
Originals values used.
Oscillating at 100KHz. I´ll change the 100pF instead of 330pF.
I want to see how it works with original parts and mods.
 

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My amp is done! Good sound and powerfull.

+-70V 4ohm load for bass bins
Two transformers (C core, 400W each) one for + and one for - rail
260KHz resonate freq.
IRFB4227 on output
(pictures in Amp.zip)

I posted PCBWizard file for my PCB. Its bacis schematic, but 330pF is 100pF, 27R gate resistors are 22R, UF4004 is MUR120 and input part with LM311 is in normal conection for high swiching freq.(Laci's schematic).Output capacitor is 1uF and output coil is 22uH.
If someone want to build this pcb with protection, tell me, because protection has R1...R8 resistors for different voltages (form +-20 to +-95V), cliping reference too for different voltages (board.zip)
 

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Ofcourse. This protection basicly is from elector (PA300 amp) but I Add signal indocator and cliping indicator

R1 - 12V drop, 20mA
R2 - Cliping refererence 3V
R3 - opamp inuputs
R4 - 15V drop, 15mA
R5 - relay droper, 24V drop, 24mA (if coil on relay is 1K)
R6 - AC conector, 0.5mA (example +-60V / 0.5mA= 120K)
R7 - same like R4
R8 - same like R4

Example for R1

Resistor (k Ohms) = ( Supply Voltage - 12 ) / 20mA
Power (mW) = ( Supply Voltage - 12 ) ^2 / Resistor (k Ohms)

For a 45 Volt supply, we get ...

Resistor = ( 45 - 12 ) / 20 = 33 / 20 = 1.65k Ohms
Power = (45 - 12 ) ^ 2 / 1.65 = 33 ^2 / 1.65 = 1089 / 1.65 = 660 mW

Example for R2 cliping reference

Current (mA) = Reference Voltage - So a 3V reference requires 3mA
Resistor (k Ohms) = ( ( Supply V - Reference V ) / Current (mA) ) * 2
Power (mW) = Current ^ 2 * Resistor

An example would be an amp with 45V supplies, and requiring a reference voltage of 5V. So ...

Current = 5mA
Resistor = ( ( 45 - 5 ) / 5 ) * 2 = ( 40 / 5 ) * 2 = 16k Ohms
Power = 5 ^ 2 * 16 = 25 * 16 = 400 mW

I posted word document with table of values if some one dont want to calculate values of resistors, schematic to.

Values for R7,R15,R17,R16 on amplifier are from basic scehmatic of amplifier

Regards
 

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Thank you very much dzony, I'll put the pcb files with protections and smd components as soon as I finish it..

I managed to get solder paste. So maybe later I will experiment some with DirectFETs, they would really increase the performance of the amp.

I use a much simpler relay protection. It is not as effective, has higher treshold, but every component fits under the relay in SMD.
An externally hosted image should be here but it was not working when we last tested it.
 
I managed to get solder paste. So maybe later I will experiment some with DirectFETs, they would really increase the performance of the amp.

I use a much simpler relay protection. It is not as effective, has higher treshold, but every component fits under the relay in SMD.
An externally hosted image should be here but it was not working when we last tested it.

nice. Yeah the Direc-fets are way to go, I havent seen such low rdsOn anywhere but be precise when drawing the footprints and carefull when soldering; If you have a homemade pcb cover coppertracks with very thin layer of tin otherwise you will short the drain(the can) with pcb tracks and don't add too much paste, better too little if youre using PbF devices. Also what I've learnt when soldering the critters is that you can temprorarily leave you multimeter wired to the pcb tracks that go to mosfet, dial it to diode test and see if it shorts while your blowing the hot air. If it shorts at some point of soldering you just slightly move it with tweezers till it snaps in place..
 
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