900W H-class PA Amp with Limiter

apex,
in psu schematic low voltage per rail capacitance bank is 20,000uf + another 20,000uf
rail to rail low voltage 40,000uf.
HIGH VOLTAGE another 40,000uf rail rail
operating in HV + LV capacitance bank is only 20,000uf per rail because 20,000uf in series is = 20,000uf operating in 40,000uf rail to rail,
using a 2500VA transformer required for h900
i was thingking capacitance bank is not enough,operating it in stereo h900+h900,
i was thingking 60,000uf per rail is good,i use the word GOOD because i need your confirmation,so a total of 120,000uf for 2500kva trafo, two h900 module,
please enlighten us.
 
apex,
in psu schematic low voltage per rail capacitance bank is 20,000uf + another 20,000uf
rail to rail low voltage 40,000uf.
HIGH VOLTAGE another 40,000uf rail rail
operating in HV + LV capacitance bank is only 20,000uf per rail because 20,000uf in series is = 20,000uf operating in 40,000uf rail to rail,
using a 2500VA transformer required for h900
i was thingking capacitance bank is not enough,operating it in stereo h900+h900,
i was thingking 60,000uf per rail is good,i use the word GOOD because i need your confirmation,so a total of 120,000uf for 2500kva trafo, two h900 module,
please enlighten us.

Use this PSU per channel, but in commercial brand PA amps is usual to use 8x10000uF for two channels.
Regards
 
Use this PSU per channel, but in commercial brand PA amps is usual to use 8x10000uF for two channels.
Regards
yes you are right,commercial amp is like that
but,
in diy amp,
see pass aleph 1.2 2x68,000uf per rail or make it 4
see superleach 300w monoblock use 34,000uf bank
and check nmos power table 165w 13,000uf per rail

by leach
Power Supply Components

The power supply circuit diagram is the same as for the Low TIM Amplifier. The parts are the same with the following exceptions.

* T1 - The transformer should have either a center tapped secondary or two separate secondary windings which can be wired in series. With 120 V ac rms applied to the primary, the no load secondary voltage should be 120 to 130 V ac rms for a center tapped secondary or 60+60 (60x2) to 65+65 (65x2) V ac rms for two secondary windings. This should give a no load amplifier power supply voltage of plus and minus 85 to 93 V dc. Some transformers are rated at 115 V ac rms on the primary. With 120 V ac rms applied, the secondary voltage will be greater by a factor 120/115. If the transformer is rated at full load, its no load voltage will be 15% to 20% higher. I would recommend a transformer current rating of at least 6 A. The transformer I used in each of my two original Double Barreled Amplifiers was the Signal 230-6. It had two center tapped 115 V 6 A secondaries which I wired in parallel to obtain a secondary rating of 115 V at 12 A. The primary had three voltage taps: 105 V, 115 V, and 125 V. I wired the AC line input to the 115 V tap. With 120 V AC applied to the 115 V tap, I got plus and minus 85 V DC on the power supplies and 270 W into an 8 ohm load. If I had used the 105 V primary taps, the power supply voltage would have increased to about 93 V and the amplifiers would have put out over 300 W. The Signal transformer was definately an overkill. It weighed 38 pounds. But it would really kick you know what. To my knowledge, this transformer now is available only by special order.
* C1P, C2P - I used two Mallory CG832U100G1 8,600 uFd 100 V capacitors in parallel for each of these so that I had 34,400 uFd total in each of my two amplifiers. This was probably an overkill. The energy stored in the eight apacitors was about 250 joules. This is enough energy to lift a 25 pound dog over 7 feet off the floor. For C1P and C2P, I would recommend at least 10,000 uFd total for each. The voltage rating should be 100 V or greater.

by Mr. Pass
 

Attachments

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Use this circuit for stereo, only add DC protect for channel 2. If you have two heatsinks add BD241C(TIP31C) in parallel.
Regards

Hello APEX

have add in your PA PROTECT design

1. LED WARNING ! HEATSINK TEMP 75deg !

and

2. 35deg FAN ON / OFF (dont like noisy FAN if using amp with low output power or HI-FI)

could this work ?
 

Attachments

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i have no scope sir i have only DMM....

Multi meter can read only DC or 50Hz RMS AC voltage. If you use LED instead NSL32, and run amp with 0,+/-55v,+/-110v rail voltage, LED will light on if you have 95v peak voltage on amp out with high level audio input. With low rail voltage of +/-55v, amp will clip at about 50v output voltage, and LED can't light on if step driver not work and not increase rail to +/-110v at peaks.
 
Hello APEX

have add in your PA PROTECT design

1. LED WARNING ! HEATSINK TEMP 75deg !

and

2. 35deg FAN ON / OFF (dont like noisy FAN if using amp with low output power or HI-FI)

could this work ?

Your circuit for 35deg fan on/off is wrong. Use PNP transistors to switch fan (+) to GND. PA protect is for B500 and H900, I just suggest not use stereo PA protect for this powerfull amps.