Ultra Simple Class D

[CPX]

Norazmi please make thd and imd measurements from 100mA load to 10A load.Thanks.

 

[rezamir]

tnx norazmi for help
best regard.

 

[de Ocampo]

Hi all,

This is my first approach on class D amp, I'm glad I have found a simple project in which used components I already had. I may put them in good use by constructing this amp, however I am being confused, it seems that the schematic that Norazmi posted was different than the projects of Andrew, rezamir and irvynejay which to my knowledge was being discussed in this thread.. and the smps link do not work for non-members (posted by Andrew).

I definitely wanted to construct this project, will someone share the construction files..

Thanks & Regards!

 

[norazmi]

there is no different, Irvy use 2 pcb together and make it stereo. adrew made 1 pcb for mono and maybe he will make new one to have it stereo. rezamir just draw hes own pcb but still use same schema that i`ve posted. as u always make ur own as u wish no problem.

abeteer u can use from original i posted and it should work without problem.

 

[de Ocampo]

norazmi,

thanks, but I don't see BD139/140 in the schematic there are 4 pairs of MPSA and a couple of BCs, was the pre-driver MPSA replaced by 2Ns? and the combined MPSA/BCs drivers replaced by BDs? Also what are the parts value with DNP indicated...it may be of help on what diameter of torus will I need and how many turns of wire.

I may be asking too much please consider.


Cheers!

 

[norazmi]

both work, using bds transistor is the replacement for the current design. and u can replace mpsa with 2n siries. Fot the inductor u need to measure it or u can do with EI33 with 2-3 mm gaps wound it about 14-15 laps awg 18.

 

[de Ocampo]

thank you norazmi, I'll get back to you later on, in the meantime I will be completing the parts and do the etching job..I did try to dis-assemble one EI33 taken from a discarded PSU, unfortunately the E was split into two parts, it seems that these small ferrite cored transformer is very fragile.

Ciao!

 

[de Ocampo]

I got here a few sizes of T106-2 which one will suit best to the amp? I will be using +/-24VAC 6amp power trans.

Thanks!

 

[andrewlebon]

T106_2 CORE DIMENSIONS

T106-2 13.5 1.06 0.560 inch 0.440 inch 2 10
od id height

 

[andrewlebon]

1.06 INCH IS OUTER DIAMETER
.560 INCH INNER DIAMETER
.440 INCH IS HEIGHT

 

[de Ocampo]

thank you andrew...I will be checking on that!
by the way how many turns of AWG#18 to come-up with 35uH....did I read it correct?

 

[andrewlebon]

Hi Abeteer
greetings well i dont have this core T106_2 so its hard to tell the amount of turns trying to find t106_2 core norazmi uses this core so he will be able to tell you
warm regards
andrew lebon check DIYSMPS SITE

 

[andrewlebon]

i would like to suggest u do 40 turns, estimated inductance will be 22uh and use awg18
NORAZMIS reccomendation of no of turns for T106_2 core

 

[de Ocampo]

OK, will wait for norazmi's advice. Thanks for the help!

Cheers!

 

[norazmi]

T106-2 iron powder, u can make 30 uh with 47 turn and +/- 24 vac is good and no problem with that supply. For the EI ferrite core if u want u can dis-arm with boiling hot water about 10-15 mins, it will dis-arm itself or u can use thinner after boiling it.

 

[irvynejay]

t106-2

40 turns #18 on red core=21.70uh

16 turns x 10/5 #22 T157-2 blue core =22.07 uh

 

[de Ocampo]

Thank you guys, that's a lot of help I will be using T106-2 red core.
Irvyn, nice meter you got there is it a DIY?


Regards!

 

[irvynejay]

its only diy lc meter its available on the web you just need PICKIT 2 software and hardware to program the PIC 16F XXX ic.

 

[gloriel]

I made monoblok of this amp. it's work on 4 ohm fullrange speaker. i tried to drive sub vdc with 8 ohm configuration, i found that the induktor ringing when the bass come. Supply with 48VDC 7 amp. What must i do?

 

[norazmi]

specified ur inductor specs, such as core material, uh, coil size... because of large current draw through inductor, improper coil size or winding may cause it vibrating.