ok I need a power source for a amplifier that uses ac28v-0-28v and I would like to get a colloidal transformer ,but they are expensive from china I cant seem to find a American company that sell retail or to the public and I don't understand all the math and numbers trying to find the one I need.
also is there a way I can use dc going into a dc/ac converter,I do not know any thing about electricity and want to play it safe and ask for help.
here is the amp Wholesale Product Snapshot Product name is 5HZ-100KHZ fr Power Amplifier FET Board Stereo Amplifier Board with Heat Sink AC28V Dual Power Input #110013
also is there a way I can use dc going into a dc/ac converter,I do not know any thing about electricity and want to play it safe and ask for help.
here is the amp Wholesale Product Snapshot Product name is 5HZ-100KHZ fr Power Amplifier FET Board Stereo Amplifier Board with Heat Sink AC28V Dual Power Input #110013
read Decibel Dungeon and Elliot Sound Products
They are very good starter pages.
BTW:
you need a centre tapped transformer, a bridge rectifier and a pair of smoothing capacitors.
That is the complete AC to DC PSU (dual polarity).
They are very good starter pages.
BTW:
you need a centre tapped transformer, a bridge rectifier and a pair of smoothing capacitors.
That is the complete AC to DC PSU (dual polarity).
wow I am lookikng at the Elliot sound web site i think I sould find all my answers here ,I will look at the other site later, Thanks AndrewT.
can you tell me what to look for in the meantime i need115v American and 28v-0-28v 15v-0-15v and what rectifiers and smoothing caps
Waow! "Colloidal Transformer": what's that, I never heard about it? Is it the latest audiophoolery novelty item?
I am eagerly awaiting for the "Colonic Irrig Transformer", that's going to be real fun...
I would do some serious homework reference your choice of amplifier.
The smoothing caps look woefully small for an amplifier that is going to develop any serious power or performance.
The fact that you state you know nothing about electrics and get a toroidal transformer mixed up tends to indicate that you shouldn't be undertaking such a project until you have a bit more understanding under your belt.
The smoothing caps look woefully small for an amplifier that is going to develop any serious power or performance.
The fact that you state you know nothing about electrics and get a toroidal transformer mixed up tends to indicate that you shouldn't be undertaking such a project until you have a bit more understanding under your belt.
you are probably correct,But I so much wanted to do this amp. I have done most of the class d amps they are not a difficult.
thing is I already have the amp in hand,if some one could build me a complete power supply .send me a pm or tell me some thing I can do.otherize I have a amp board that is useless.
Transformers never cheap and shipping costs a bunch.
Try this ApexJr link: miscellaneous.html
Output: 2 X 28.4V @ 2.67Amps over 150Va
$22.00ea
This would serve your basic need.
Try this ApexJr link: miscellaneous.html
Output: 2 X 28.4V @ 2.67Amps over 150Va
$22.00ea
This would serve your basic need.
I don't think so, it's a 280W amplifier. It'll need something approaching a 600VA transformer into 4 Ohms.
Most people with Serious experience can tell that +/- 30VDC will not develop anything close to 280W@8Ohms and 560W@4Ohms is hilarious.
Try a figure of 100W if lucky into 8Ohms for a short period of time.
I am not Seriously going to believe any Chinese spec. sheet in the first place.
Serious commercial amplifiers in Class B service delivering this level of power are quite substantial mechanically (heat sink).
I figured 50W per channel was a Serious and safe figure.
Nobody seemed to address the specific question at all: What transformer and from where ?
Try a figure of 100W if lucky into 8Ohms for a short period of time.
I am not Seriously going to believe any Chinese spec. sheet in the first place.
Serious commercial amplifiers in Class B service delivering this level of power are quite substantial mechanically (heat sink).
I figured 50W per channel was a Serious and safe figure.
Nobody seemed to address the specific question at all: What transformer and from where ?
That's 30-0-30VAC which will give 42V rails.
Admittedly the spec sheet is absolutely cr*p, it might be bridged, we just don't know.
Admittedly the spec sheet is absolutely cr*p, it might be bridged, we just don't know.
I agree that the Unloaded output voltage will be +/- 42VDC.
I assumed that when a transformer is Loaded to specification, the power supply output DC voltage approaches the transformer RMS voltage rating.
I still don't see any transformer recommendations ?
I assumed that when a transformer is Loaded to specification, the power supply output DC voltage approaches the transformer RMS voltage rating.
I still don't see any transformer recommendations ?
Properly designed, the supply voltage will be the peak of the specified rms voltage.
If it's a 30V rms winding, full wave rectified at rated current, the rectifier output would be 30 x 1.4, or 42Vdc.
Take a look at Antek transformers. These have two separate secondaries. You can use a capacitor pcb from the DIY store.
Universal PSU V3 - Power Supplies and Accessories - Circuit Boards
Transformers - 500VA - AnTek Products Corp
Transformers - 600VA - AnTek Products Corp
Transformers - 800VA - AnTek Products Corp
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Did you look at the bridge rectifier a S4VB40 ? At least in the data sheet I looked at it's rated as a 2.6A part well that sort of goes along with the tiny filter caps doesn't it !
Hi,
No you don't, just the transformer.
A perusal of the back of the PCB indicates to me it cannot not bridged.
(As well as a 3 wire speaker output also cannot also be bridged.)
The Mosfets are double parallel pairs, fair enough.
The suggested Apex Jr. transformer is an excellent choice IMO.
rgds, sreten.
FWIW I haven't seen the CA3046 chip for a long time, a very old
favourite, 5 matched transistors on a chip, no idea what its doing.
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Hi,
I'd also update one pair of the 1000uF supply caps
(each rail has 2x1000uF in parallel) to 3,300uF.
I might or might not worry about the L15's being
straight wire when a simple few turns air coil is
trivially more expensive, I'd change it looking
at the the other R and C values of the Zobel.
rgds, sreten.
Also note Mosfet amplifiers don't swing near the
rails anywhere near as good as BJTs. The specs
are absolute nonsense. Stlll its not bad value,
for paralleled Mosfet ouputs, the parallel devices
allow a better output swing, and better heatsinking.
I'd also update one pair of the 1000uF supply caps
(each rail has 2x1000uF in parallel) to 3,300uF.
I might or might not worry about the L15's being
straight wire when a simple few turns air coil is
trivially more expensive, I'd change it looking
at the the other R and C values of the Zobel.
rgds, sreten.
Also note Mosfet amplifiers don't swing near the
rails anywhere near as good as BJTs. The specs
are absolute nonsense. Stlll its not bad value,
for paralleled Mosfet ouputs, the parallel devices
allow a better output swing, and better heatsinking.
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Yes the apex transformer seems a safe and economical bet,yes the description said
FET stereo amplifier board with professional heat sink, using TIP differential FET driven. 8 VMOS power FET parallel output ,with rectifier and full protective device, with its high-speed, high dynamic, low intermodulation distortion, negative temperature coefficient effect
so I assumed all I would need was a transformer,I know it will not come near stated specs,but it might surprise me.it should be adequate though.just want to see how the chinese AB amps are,I am happy with the Class d And chip amps.And I am learning a lot about electronics,Glad I have people like you all to back me up and help out.
oh i will be using 4 ohm speakers.
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