900W H-class PA Amp with Limiter

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#2,921
CIPRIANDRAGOS said:
sure,all components are in good position (diodes,transistors and capacitors)
The amplifier sounds ok on speakers (i didn't put volume until 32-33 Vrms on speakers) but oscilloscope say the truth
I use 8 ohms dummy resistors for load and i let him at 40-45 Vrms on output and no component getting to hot,the temperature is ok
Some one tell me to change the zener ZF15V from bases of 2sc5200 and 2sa1943 and try with PL12Z zener and PL18Z zener to see what is happens
Another thing,if i shortcut the source with drain from mosfet's ,amplifiers working great but then i have only Class AB 🙁
In my case the step up translation is not working well that is clear...
Click to expand...

so u mean with 40-45vrms the stepper dosn't work rite? still on mv and after clip not switch to hv iam rite?
and u sure the gv is there, i mean on stepper. if yes.. it must working. like another suggest try it first and see what happen, with ZF15V the clip work if output get 40vrms but u not get it, so try to use PL12Z and see what happen.
 
#2,923
CIPRIANDRAGOS said:
No,the spikes appears at 32-33Vrms on output.I say on 40-45 VRms the amplifier work well like temperature but the spikes are still there.i will put some pictures to see what is happens with graphic when the stepper make the switch.
My case is same like in this video
http://m.youtube.com/watch?v=yDeoWq8Cw7s
Maybe mister Mile know the problem
Click to expand...

The spikes are resulted by the switching. Maybe You have to slow down the switching little bit. Too fast switching makes this kind of glitches, because of the internal capacitances of the semiconductors.

Sajti
 
#2,925
Here is some picture with my Apex H900 results
1.Sine wave before switching
2 Sine after switching
3. Square wave on input at 10 Khz
4. Square wave on output at 10Khz

Please ,any suggestion ?What i must do?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
 
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#2,926
Ok, the pictures are even worse, comparing with the first video.
Can You please put some pictures about the switching waveform? I mean the collector of the output devices. And it would be great to se the output signal, and the collector voltages same time.

Sajti
 
#2,927
One more idea:

the squaerwave shows very limited slew rate. Please check all of Your small capacitors, if the values are correct.
C2, C5, and the 100pF capacitors between the base and collector of the MJE-s.

Sajti
 
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#2,931
Hello friends,
Can anyone please provide me all the PCB design like PSU,circuit PCB board and other files.Its hard to find these files in so many pages
I too want to build this amp
What is the difference between v1 and v2 of this amp?
Thanks

Hello trac911

Pls. Read this thread from the very beggining. All was detailed here.
 
#2,932
Hello friends,
Can anyone please provide me all the PCB design like PSU,circuit PCB board and other files.Its hard to find these files in so many pages
I too want to build this amp
What is the difference between v1 and v2 of this amp?
Thanks

Hello trac911

Pls. Read this thread from the very beggining. All was detailed here.
 
#2,935
R21:100e resistor blown

sir mile is this H900 circuit corrected or not. because my r21 100e resistor blown at first start up with series 100 w bulb and my friends H900 channal also giving crack sound
pls pls pls help me out sir I have to powered my boxes soon I made 12 pcb's and first pcb have that problem I feel lost of confidence due to that
 
#2,936
Parag99 said:
sir mile is this H900 circuit corrected or not. because my r21 100e resistor blown at first start up with series 100 w bulb and my friends H900 channal also giving crack sound
pls pls pls help me out sir I have to powered my boxes soon I made 12 pcb's and first pcb have that problem I feel lost of confidence due to that
Click to expand...

Check your Q4, Drivers and output transistors, there must be shorted somewhere, Also post some pictures so other diy friend can help you.
 
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