900W H-class PA Amp with Limiter

[sameer x1]

transistorised step

Hi
having made this h900 transistorised step only problem i am facing is negative side
step i am not getting 55 volts dc on collector outputs positive side i am getting correct
55 volts dc i have changed 2n3906 to BC560 but still high voltage on negative collector can any one help me
thanking you
samee rx1

 

[wattaniya]

hi apex sir,
can u check post no 1973.

 

[wattaniya]

hi apex sir,
I provide 50hz sinewave to h900 and i checked the out , with clipping showing 52v ac.
is this ok?
another question is that two 15v zd half watt showing 0v near the stepdriver ic 2nd pin.
why is that?

 

[wattaniya]

hi apex sir,
can u check last post, is that normal?

 

[apexaudio]

hi apex sir,
can u check last post, is that normal?

52v ac is 676W on 4R, what is rail voltage and power of transformer on your amp?

 

[wattaniya]

52v ac is 676W on 4R, what is rail voltage and power of transformer on your amp?

thanks for reply sir,
my rail voltage is 45-90-0-45-90dc.

 

[apexaudio]

thanks for reply sir,
my rail voltage is 45-90-0-45-90dc.

Thats OK, for 900W/4R you need 60v ac on amp out, and rail voltage 100-50-0-50-100v dc

 

[wattaniya]

thanks for reply sir,
is that two 15v zd half watt showing 0v near the stepdriver ic 2nd pin, is that normal?

 

[mahesh776]

Dear sir Apex,

Hello my PCB is complete please check if it is OK so i can post PCB layout for Diy to make Apex sir please guide


Thanking you
Sameer X1

sir,forgive if i m wrong -if 2sc4793 and 2sa1837 placed wrong place.

please give give me your schematic ,pcb layout,and measurement so that i can
make one.----please again
-with regards.

 

[iiee3602]

sir apex, can i replace IRF2807 with IRF540 in transistor type step driver of H900?

 

[iiee3602]

Join Date: Jan 2012
Location: Iloilo
mj777, can i replace IRF2807 with IRF540 in transistor type step driver of H900?

 

[electra_ina]

iiee...
IRF2807 used for max voltage 75vdc
IRF540 max voltage 100v

 

[iiee3602]

Transistor stepdiver

So there is no question to replace IRF2807? In our place, hard to find this trans.

 

[remle114]

So there is no question to replace IRF2807? In our place, hard to find this trans.

You can use 2pcs. IRF540 per rail instead IRF2807

 

[iiee3602]

Transistor stepdiver

Thanks for that sir.

 

[remle114]

This 2 module of H900 with discrete step driver use 2 IRF540 per rail without any problem encountered
power supply used is +/- 110-55-0-55-110 volt

 

[AndrewT]

irf540 are 100Vds devices.
How do you make them reliable with a +-110Vdc supply?

 

[remle114]

irf540 are 100Vds devices.
How do you make them reliable with a +-110Vdc supply?

Hey AndrewT look at this original schematic of H900 and ask apex and others who build this amp why they use IRF540 at +/- 120-60-0-60-120 volt rail

 

[TonyTecson]

irf540 while supplied from 120volt supply sits atop 60volts.....if Apex is confident with them, you can use them...

 

[apexaudio]

irf540 are 100Vds devices.
How do you make them reliable with a +-110Vdc supply?

On IRF540 is only 55Vdc.