hi all 
i am back with my issues about sigma delta irs900d .😡
i have tried to bridge two irs 900d without success , they always end up latching or producing noise and drawing alot of current.
i increased the output inductance to 120uh (it improved the situation but did did not help)
i added 80uh inductance to each power rail of each channel both +/- rails also (it improved the situation but did did not help)
😕the major issue ,is that when you disconnect the load from the amplifier the ,amp suddenly becomes unstable and draws alot of current like a short circuit , and the output fets heat up😕
i am back with my issues about sigma delta irs900d .😡
i have tried to bridge two irs 900d without success , they always end up latching or producing noise and drawing alot of current.
i increased the output inductance to 120uh (it improved the situation but did did not help)
i added 80uh inductance to each power rail of each channel both +/- rails also (it improved the situation but did did not help)
😕the major issue ,is that when you disconnect the load from the amplifier the ,amp suddenly becomes unstable and draws alot of current like a short circuit , and the output fets heat up😕
Hi , show the exact schematics.
Unstable - it generates on the resonanse frequency of the output filter ?
just the normal irs900d circuit by detex audio . output fets are irfp250 .supply voltage +/-38v
Attachments
in steréo mode your amplifier work good? if yes you must have a low pass filter at aop used for the bridge.hi all
i am back with my issues about sigma delta irs900d .😡
i have tried to bridge two irs 900d without success , they always end up latching or producing noise and drawing alot of current.
i increased the output inductance to 120uh (it improved the situation but did did not help)
i added 80uh inductance to each power rail of each channel both +/- rails also (it improved the situation but did did not help)
😕the major issue ,is that when you disconnect the load from the amplifier the ,amp suddenly becomes unstable and draws alot of current like a short circuit , and the output fets heat up😕
and dont run 2amplifier at same frequency
Did you use 180 degree shift? otherwise you get big trouble who looks a like as you already have explane.
regards
this circuit is not stable. use apex d200 version is good and simple. and use external 12v supply for driver regulated for less heat supply transistorhow to change frequency to 250Khzsuply +-50Vdc
yes. but also irs 900 is not stable. the best is apex d200 or macky srm450 is the same
1.what voltage did you use sir?
2.what were your output fets??
3.how many channels did you use in one casing??
4.were there any noise issues??
thanking you in advance stewin diy.
for original d200 i use +-54v with irf640n good quality not fake also no fake ir2110 and tl081. 2 channel no noise issues with good start grounding. and supply rail must be decoupled with ceramic capacitor near mosfets +and- rail. they are many bad quality capacitor in high frequency. input connector must be isolated from chassis.
for modified d200 protection added with ne555 lm311 i use +-90v irfb4227 with only r gate 10ohm without 1n4148 with it mosfet will heat like crazy and supply for ir2110 11.4v regulator 7812 +simple diode at output . its very very powerfull and no much heating. all frequency set by pot 1k at 250khz output filter sendust. theorie irf640n will not support 2 ohm at 54v but in test will work with normal heating without filure its very strong
hi protech , thanks for the reply , it is very useful.
have you tried to bridge this amp with success?
and the hi power version using irfb 4227 , have you ever tried to remove the speaker while the amp is playing loud??
yes with 2 diode at output mur1560 for me no problem at full drive. preamplifier used have a high frequency filter to avoid resonnance zone output filter. frequency is 250khz lpf 40uh + 0.47uf 600v capacitor with zobel its important 10ohm 3w or 5w + 220n 250v ceramic.
i m very happy if i can help you.
for d200 with irf640n no problem with original component
good work. i make irs 900 aud600 irs1500 irs3000 d200. the one that work with no problem at all is d200. if you add a fast over current protect lm311 ne555 and increase voltage 90v you get the best quality and stability. i changed tl081 with tl071 and the sound is different you can test it. i used a high spead aop very very expensive and i can tell you that tl081 good quality is the best
why 400khz! 200 ---250khz is the best performance and quality. there are no difference audible !!! i test all configuration. make it easy
pafi catrino. stop both. we are all here to study and help each other. There is no point in making fun of others. catrino does a nice job : irked:
hi all
i am back with my issues about sigma delta irs900d .😡
i have tried to bridge two irs 900d without success , they always end up latching or producing noise and drawing alot of current.
i increased the output inductance to 120uh (it improved the situation but did did not help)
i added 80uh inductance to each power rail of each channel both +/- rails also (it improved the situation but did did not help)
😕the major issue ,is that when you disconnect the load from the amplifier the ,amp suddenly becomes unstable and draws alot of current like a short circuit , and the output fets heat up😕
I know your problem
You.need to synch both channel switching speed. If it is difficult, set both at the same speed. At least very small difference.