UcD like topology amp.

[Bender.ru]

Here is my first selfoscillated (UcD like) amp.
Later i'm gonna gonna post schematic & pcb layout with measurements result.

Driver: IRS20955
Mosfet: IRFI4212H-117P

 

[Bender.ru]

Totem pole (20V/div*500nS/div) :

 

[Bender.ru]

LC out at idle (1V/div*500nS/div) :

 

[Bender.ru]

Clip, load 6.5 Ohm resistor (20V/div*200uS) :

 

[Bender.ru]

20kHz sine, load 6.5 Ohm resistor (10V/div*10uS/div) :
ps: signal asymmetry produced by low quality test generator.

 

[phase_accurate]

Very nice indeed.

Regards

Charles

 

[Eva]

Hey, where is the RF ringing? I don't see any 😀😀😀

Good job, indeed 😎

 

[Bender.ru]

Hi Charles, thanks for reply.

Hi Eva, i think that my relativaly low scope eat ringing 🙂, but it perfectly show terrible RF ringing of my early stuff 😀 .

 

[acid_k2]

Nice work, Bender.ru!
I like that.

Sure that you are not measuring a class A amp? 😀 or you are using a very esoteric filter.... 😀

 

[MaxS]

Hello Bender.ru and all,

Nice project.
What are voltage supply, something like +/- 45 V?

What is the approximate power ?
Maybe around 60 W and 260 W / 6R

Is it possible to get a copy of entire project ?

Thanks you !

 

[Bender.ru]

Hello MaxS, power supply is 40V per rail, higher voltage possible with IRFI4020H-117P (or something like that). Output power can be easily calculated.
Project will be shared after all measurements be done.

Next 20kHz sine:

1st: input 0.2V/div*10us/div
2nd: output 10V/div*10uS/div

load: 6.5Ohm resistor.

 

[Bender.ru]

Here is some thd measurements, nothing incredible or outstanding 😀. Next pcb version is comming soon (or not soon).

Equipment: emu1212m, 24k lowpass filter (AES-17), load - good old 6.5Ohm resistor, PSU 250W torroid with 20000uF per 40V rail.

1st: 1W.

 

[Bender.ru]

2nd: 55W (1/2 max Pout)

 

[Bender.ru]

Mininmum THD recieved at 32W output power level.

 

[acid_k2]

Thd is not so bad.... with some peaks on 3° and 7° harmonic (not really good ), especially at half power...

 

[Bender.ru]

i hope, that i could improve thd figure with some changes in schematic & pcb layout.

 

[Eva]

Have you measured generator residuals?

 

[Bender.ru]

Eva, that generator do you mean? I don't understand you 🙁

 

[phase_accurate]

Hint: How many generators do you use for this test ? 😉

Regards

Charles

 

[Bender.ru]

my only one thd test generator was emu1212m line out...so it's own thd level ~0.0004% @ 1kHz 🙂 .