Class D 200 Wrms with 2 mosfet cheap

[szhighstar]

MPP (Molypermalloy Powder Cores)
Composition: Mo-Ni-Fe

MPP cores has the lowest overall core loss and best temperature stability. Typically, inductance variance is under 1% up to 140 deg C. MPP cores are available in initial permeabilities (µi) of 26, 60, 125, 160, 173, 200, and 550. MPP offers high resistivity, low hysteresis and eddy current losses, and very good inductance stability under DC bias and AC conditions. Under AC excitation, inductance change is under 2% (very stable) for µi=125 cores at AC flux density of over 2000 gauss. It does not saturate easily at high DC magnetization or DC bias condition.The saturation flux density of MPP core is approximately 8000 gauss ( 800 mT)

Compared to other materials, MPP cores are the costliest, but highest quality in terms of core loss and stability. For application involving DC bias condition, use the following guidelines. To get less than 20% decrease in initial permeability under DC bias condition:- For µi= 60 cores, max. DC bias < 50 oersted; µi=125, max. DC bias < 30 oersted; µi=160, max. DC bias <20 oersted.

Unique Features:
1. Lowest core loss among all the powder materials. Low hysteristics loss resulting in low signal distortion and low residual loss.
2. Best temperature stability. Under 1%.
3. The maximum saturation flux density is 8000 gauss (0.8 tesla)
4. Inductance tolerance: + - 8%. (3% from 500 Hz to 200 Khz)
5. Most commonly used in aerospace, military, medical and high temperature application.
6. Most readily available as comapred to high flux and sendust.
Applications :
High Q filters, loading coils, resonant circuits, RFI filters for frequencies below 300 kHz, transformers, chokes, differential mode filters, and DC biased output filters.

 

[szhighstar]

High Flux Cores
Composition: Ni-Fe

High Flux cores is composed of compacted 50% nickel and 50% iron alloy powder. The base material is similar to the regular nickel iron lamination in tape wound cores. High Flux cores have higher energy storage capabilities, and higher saturation flux density. Their saturation flux density is around 15,000 gauss ( 1500 mT), about the same as iron powder cores. High Flux cores offers slightly lower core loss than Sendust. However, High Flux's core loss is quite a bit higher than MPP cores. High Flux cores are most commonly used in application where the DC bias current is high. However, it is not as readily available as MPP or Sendust, and are limited in its permeability choices or size selections.
Applications :

1) In Line Noise filters where the inductor must support large AC voltages without saturation.

2) Switching Regulators Inductors to handle large amount of DC bias current

3) Pulse Transformers and Flyback Transformers as its residual flux density is near to zero gauss. With the saturation flux density of 15K gauss, the usable flux density ( from zero to 15K gauss) is ideally suited for unipolar drive applications such as pulse transformer and flyback transformers.

 

[szhighstar]

Kool Mu® / SENDUST
Composition: Al-Si-Fe

Sendust cores are also known as Kool Mu® from Magnetics Inc., Sendust material was first used in Japan in an area called Sendai, and it was called the 'dust' core, and thus the name Sendust. In general, sendust cores have significantly lower losses than iron powder cores, but have higher core losses than MPP cores. Compared to iron powder, sendust core loss could be as low as 40% to 50% of Iron powder core loss. Sendust cores also exhibits very low magnetostriction coefficient, and it is therefore suitable for applications requiring low audible noise. Sendust cores has a saturation flux density of 10,000 gauss which is lower than Iron powder. However, sendust offers higher energy storage than MPP or gapped ferrites.

Sendust cores are available in initial permeabilities (Ui) of 60 and 125. Sendust core offer minimal change in permeability or inductance (under 3% for ui=125) under AC excitation. Temperature stability is very good at the high end. Inductance change is less than 3% from ambient to 125 deg C. However, as the temperature decreases to 65 deg C, its inductance decreases by about 15% for µi=125. Also note that as temperature increases, sendust exhibits a decrease in inductance versus an increase in inductance for all the other powder materials. This could be a good choice for temperature compensation, when used with other materials in a composite core structure.

Sendust cores cost less than MPPs or high fluxes, but slightly more expensive than iron powder cores. For application involving DC bias conditions, use the following guidelines. To get under 20% decrease in initial permeability under DC bias condition:

For µi= 60 cores, max. DC bias < 40 oersted; µi=125, max. DC bias < 15 oersted.


Unique Features:
1. Lower core loss than Iron Powder.
2. Low magnetostriction coefficient, low audible noise.
3. Good temperature stability. Under 4% from -15 'C to 125 'C
4. Maximum flux density: 10,000 gauss (1.0 tesla)
5. Inductance tolerance: ±8%.
Applications:
1. Switching regulators or Power Inductors in SMPS
2. Fly-back and Pulse transformers (inductors)
3. In-Line noise filters
4. Swing chokes
5. Phase control circuits (low audible noise) light dimmers, motor speed control devices.

 

[szhighstar]

Iron Powder
Composition: Fe

Iron powder is the most cost effective of all the powder cores. It offers a cost effective design alternative to MPP, High Flux or Sendust cores. Its higher core loss among all the powder materials can be compensated by using bigger size cores. In many applications, where space and higher temperature rise in the iron powder cores are insignificant compared to savings in costs, iron powder cores offers the best solution. Iron Powder cores are available in 2 classes : carbonyl iron and hydrogen reduced iron. Carbonyl iron has lower core losses and exhibits high Q for RF applications.

Iron Powder cores are available in permeabilities from 1 to 100. The popular materials for SMPS applications are #26 (µi=75), #8/90 (µi=35), #52 (µi= 75) and #18 (µi=55). Iron powder cores have saturation flux density of 10,000 to 15,000 gauss. Iron powder cores are quite stable with temperature. The #26 material has temperature stability of 825 ppm/C (inductance change of approximately 9% with temperature change of up to l25 deg C).The#52 material is 650 PPM/C (7%). The #18 material is 385 PPM/ C (4%), and the #8/90 material is 255 PPM/C (3%).

Iron powder cores are ideal in lower frequency applications. Since their hysteresis and eddy current core loss are higher, the operating temperature should be limited to below 125 deg C.

For application involving DC bias conditions, the following guidelines are recommended. To get under 20% decrease in initial permeability under DC bias condition:

For Material #26, max DC bias < 20 oersteds;
For Material #52, max DC bias < 25 oersteds;
For Material #18, max DC bias < 40 oersteds;
For Material #8/90, max DC bias < 80 oersteds.

Unique Features:
1. Lowest costs.
2. Good for low frequency application (<10OKhz).
3. High maximum flux density: 15,000 gauss
4. Inductance tolerance ± 10%
Applications:
1. Energy storage inductor
2. Low frequency DC output chokes
3. 60 Hz differential mode EMI Line Chokes
4. Light Dimmers Chokes
5. Power Factor correction Chokes.
6. Resonant Inductors.
7. Pulse and Fly-backTransformers
8. In-line noise filters. Able to withstand large AC line current without saturation.

 

[paskal]

I used t-106 -26 from old pc power supply and used a hack saw to cut a 3mm gap .
turns was 18turns making it 20uh

stewin, i do think it's because of your core. probably it still saturate causing the amp to see a short. material #26 have a permeability of 75 and i've used them before. they're fine in low volume/low current but when you huge current through them they'll saturate. norazmi suggested me to try use the ferrite core which is also available from a pc power supply. never tried them but a lot of people are reporting very good feedback from it. remove the original winding and cut 1-2 mm of gap in the center pole.

if DC currents pass the inductor, advise to use powder iron or Sendust or MPP or high Flux core

szhighstar, do you know which of material that are stable with high current, suitable for switching frequency around ~400khz and doesn't require too much winding to get 20-30uH?

i've been using T106-2 iron toroid and they require just too much winding to get 30uH. i'm gonna run out of magnet wires in no time with them. your advice on the matter would be much appreciated

 

[stewin]

stewin, i do think it's because of your core. probably it still saturate causing the amp to see a short. material #26 have a permeability of 75 and i've used them before. they're fine in low volume/low current but when you huge current through them they'll saturate. norazmi suggested me to try use the ferrite core which is also available from a pc power supply. never tried them but a lot of people are reporting very good feedback from it. remove the original winding and cut 1-2 mm of gap in the center pole.

thanks paskal
ferrite are difficult to cut through can i use a piece of cd to make the 1mm gap?

 

[michelle]

Hi Szhighstar
greetings which is the best core material for dclass amps switching freqency 300Khz POWER OUTPUT 3KW SENDUST MATERIAL OR IRON POWDER MATERIAL 2
warm regards
michelle

 

[Abet]

Hi guys!

..just wanted to know if anyone of you has tamed the heat dissipation of the BDs...

@Stewin,
Was the image below is working stable?

TY!

 

[stewin]

yes it is working and very stable tested up to +/-42vlts . also pls use etd ferrite core with 1 mm gap.

 

[Abet]

Nice to hear that Stewin,

Can you post the image of the ETD ferrite core that you have used? TY!

Regards!

 

[stewin]

just be patient guys i get a hold of a camera and i will do the above

 

[jlester87]

What is the limiting factor of this amp in running past 50V?

Thanks

 

[stewin]

What is the limiting factor of this amp in running past 50V?

Thanks

very nice question i hope one of the professionals answer it




here is my latest schema and pcb i have included the gate resistor and diode

 

[stewin]

hi all just found this schema by detex audio seems simple . what makes it 100watts and not 200 watts?

 

[jlester87]

I noticed that this 200w amp doesn't have an input cap... I want to put one, can I use a polarized one like in IRS900? or a non polar cap?

 

[paskal]

I noticed that this 200w amp doesn't have an input cap... I want to put one, can I use a polarized one like in IRS900? or a non polar cap?

you refer to the simple amp posted by stewin above or another 200w amp? the one above have a 4.7uf 16v cap with 27kohm input impedance. you can use polarized cap but non-polar or film cap are usually more preferable. most design could be modified with increased input impedance which allow the input cap value to be reduced, allowing high quality film cap to be used.

 

[pravpa]

Class D 200 Wt RMS with Mosfet Cheap

Hi Norazmi
greetings thanks for your help amp came on first time clear and powerful
sound i will post clear pictures for forum now only looking for actual core really thankful
and grateful for your guidance wish there were more guys like you around to share
their expertise my transformer is 22 o 22 ac secondary is it ok there is no heating of
mosfets only output coil heating little gap is 3mmis it ok but i am happy with sound quality and power its my first d class amp and i hope to make many more
warm regards
michelle

Hi there,
Michelle can you share the pictures of successful work on forum so I can refer it. Though i am also making an subwoofer amp., but this is Great..

Thank You,

 

[john carlo]

norazmi i need help for my 3 pairs mosfet im using irfp250n i want to load at 2.6 or 2 ohms for high voltage at +/-98 vdc plz plz irfp250n can handle this specs that i wanted. coz i have here 70 0 70 ac trafo 12 amps i need your assistance sir...or wat mosfet that im going to use for compatible this kind of specs that i want.thank you

 

[pravpa]

Here again, this one i already made and success, idk if this amp can provide true 200 wrms but i aim at least 100 wrms, tested run with +- 45 vdc both linear supply and smps, 4 ohm still running cool, mosfet i use irf540 and irf9540, 1 uf filter cap, t106-2 iron powder core 22 uh. i`ll post later some of my picture finish amp and its small

credit goes to owner edtagle i think hes name at forosdeelectronica forum.

here is the schematic attach.

Hi Norazmi,

after reading all the pages on this article, I am tempted to go for this, being the electronics hobbyist I have had made several small circuits, though Techincally not into electronics but still, I can recognise all electronics parts. As it is I was Planning to make subwoofer amp. for personal use.

Regards,
PravPa

 

[gloriel]

Hi Norazmi,

after reading all the pages on this article, I am tempted to go for this, being the electronics hobbyist I have had made several small circuits, though Techincally not into electronics but still, I can recognise all electronics parts. As it is I was Planning to make subwoofer amp. for personal use.

Regards,
PravPa

for obtain best sonic of this amp, pls refer to original part, use irf530/9630 instead of irf540/9540. matching gate charge and Ciss are the first thing. you will get a very good sonic from low to high, comparable to any AB class. it will have unique sound character, almost like KN7*** keyboard series.

Glo