Power Supply for 500W+500W Amplifier

[Pittbull]

Hello guys,Im new here, can you give some idea in designing a power suuply for my 500W amplifier, my amplifier requires 50V supply and at least 14 amp current, hope you help me with this problem.


Thanks in Advance guys......

[wakibaki]

Here's a table showing voltage and current @500W for various speakers.

500_amp_psu.jpg

You'll need a transformer with dual output equal to the RMS voltages shown e.g. 45 - 0 - 45 for 4 ohms. The current shown is for one channel only, so 22A+ for 4 Ohms 2 channels. Transformer probably needs to be ~2000VA or greater.

500WPC is a BIG amplifier. I think that if you do not know how to design the power supply you are taking a big risk to build such a big amp.

w

[Cristi]

For this voltage and current level you'll definitely need to use a SMPS not a linear supply. have a look at the available ones: Connexelectronic

[nigelwright7557]

The simplest solution is a transformer, bridge rectifier and smoothing capacitors.

[Pittbull]

The simplest solution is a transformer, bridge rectifier and smoothing capacitors.

do you a schematic or block diagram sir?

You'll need a transformer with dual output equal to the RMS voltages shown e.g. 45 - 0 - 45 for 4 ohms

what kind of transformer? toroidal or just traditional EI Transformer?


heres my problem, i already have a amplifier, and its only 50Wrms, the problem is i bought a wrong speaker set, all of my speaker has a required wattage of allmost 150Wpeak, 2 mid-range 150Wpeak, 1 woofer 200 Wpeak and a tweeter 150Wpeak, so the total is atleast 650watts, is the 500W amplifier overkill or should i reduced it too, 200W?

@Cristi

thanks for the link sir

[wakibaki]

Toroidal or EI, both are acceptable.

Better you should post links showing which speaker drivers you have. Have you built them into an enclosure with a crossover?

150W peak = 75W rms.

You can run these speakers with separate amplifiers, so better to let us know exactly what you've got before going any further.

w

[Pittbull]

Toroidal or EI, both are acceptable.

Better you should post links showing which speaker drivers you have. Have you built them into an enclosure with a crossover?

150W peak = 75W rms.

You can run these speakers with separate amplifiers, so better to let us know exactly what you've got before going any further.

w

i dont have a link for it but this this is there specs,
for woofer KONZERT SG-6W, (150-200W, 60Hz-5KHz, 91 dB SPL, 8 OHMS IMP),
Mid-range KONZERT SG-5M ( 150W, 500Hz-8Khz, 91 dB SPL, Fs=500HZ, and 8 OHMS IMP)
and my Tweeter (5KHz-20KHz, 91 dB SPL, 150W, 8 OHMS IMP)

yes i built it in enlosure with crossover heres the image of my crossover design

2nd Order Reverse Polarity

4000 Hertz / 500 Hertz

8 Ohm Tweeter / 4 Ohm Mid / 8 Ohm Woofer
2.45 db Bandpass Gain, Spread = 8 : 3 octaves


its in 2nd order reverse polarity and here are its parts

Parts List
Capacitors
C1 = 2.46 uF
C2 = 53.85 uF
C3 = 4.38 uF
C4 = 19.7 uF
Inductors
L1 = 0.64 mH
L2 = 2.64 mH
L3 = 0.26 mH
L4 = 5.15 mH

Note: 2 Mid-range speaker are in parallel to my design

[AndrewT]

Hi,
if your three drivers are 100W, 75W & 75W (genuine, long term, no damage, average input power) then an amplifier between 50W and 200W would be about right to drive the speaker.
Certainly not 500W.

I suspect the tweeter is rated to match a 150Wpk speaker system. There are very few tweeters rated to 150Wpk.

To get these range of powers you would need a transformer of 30+30Vac (60W per channel into 8ohms) or 35+35Vac (100W per channel into 8ohms) or 40+40Vac (160W per channel into 8ohms)

[BobEllis]

Just because a driver is rated at a certain power doesn't mean it needs that much power. If you look at the data sheet there is probably a note for the power rating such as "IEC 268-5, via High Pass Butterworth Filter 2500Hz 12 dB/oct." This means that the driver doesn't see the full power of the system driving power. The woofer rating is usually it's thermal rating. Depending on the enclosure, you may reach xmax before you reach the thermal limit.

If this is for PA use, limit your amp to 200W. Don't go too much lower or you may drive it into clipping and fry the tweeter. For home use you can get away with a lot less power. 45v-0-45V @ 1KVA is about where you should be for PA use. For home use, follow one of Andrew T's suggestions, at 4-500VA.

You may also want to start a thread in the mutli-way speaker forum to get some help with your XO. At a minimum you'll want to pad down the mids, since a pair in parallel gets you 97 db/2.83V sensitivity. Unless the cabinet is very wide or placed very close to the wall, you'll probably want to add some baffle step compensation. Have you measured the response of your drivers in the cabinet?

[Pittbull]

thank you BobEllis and AndrewT that enlightened me up,

i guess ill have to stepdown my amplifier to 200Watts, i found here a 200W amplifier that requires 50v+50v supply, is this good?

My design is for my personal use (Home Theater, etc....), i already made my enclosure and test the whole system in the audio shop where i bought the speakers, it sounds good and i feels like im watching on cinema. . . .

since a pair in parallel gets you 97 db/2.83V sensitivity

really? do i need to put a loss pad to reduce its sensitivity?

Have you measured the response of your drivers in the cabinet

how sir? i dont know too measure it, i have little knowledge about speaker system.

i guess i have to make a new thread for my XO,

so i think this is my last question,
is 50v-50v 500VA good?
how many capacitors do i need?
how much capacitance i need? and how about audio hum?
how can i remove or prevent it?