YJ-IRAUD 350

[basreflex]

I have only bridged amps, so bus pumping is no issue. nothing to do with the mosfet type...
here are the ferroxcube inductors TN26 Al=113 n=17 L=33uH. C=2x0.33uF wima 10 series impulse type. had to place the caps horizontal one on top, one below the pcb glued with epoxy.. next step is test

 

[basreflex]

I did put zeners in to fix the bus pumping, but after setting the deadtime to 25nsec, pumping was no issue anymore. definitively dead time was the culprit. the infineons end up much faster as the drive charge is so much less.

 

[chienmort]

I am confused basreflex. The IRAUD350 is the large red PCB in your picture but you are modding the small PCBs. Are they also 2092 based amplifiers?

 

[basreflex]

yes, they are also 2092 amps but with the IRFI4019 (150Vmax). they have no relay protection, but temp, UVLO, overvoltage, dc offset . I did replace the 4019 for 4020 (200V) as they run on the same rail as he IRAUD350's. I did mod the 350's with the T106-2 as the bridge amps have an 8 ohms load , while the smaller blue have amps have 16 ohms also BTL. i'm using the rectifiers of the 2 350's also to the dc rails of the blue ones and tie the rails together of the 2 350's to prevent pumping. so in total 4 rectifiers are paralelled. the 350's are used for the LF section (12"faital-pro 500 series in tapped horn, the 2 blue ones for the HF section (8x 3FE25 in line faital-pro) + nanodsp for signalmanagement

 

[nigelwright7557]

I did put zeners in to fix the bus pumping, but after setting the deadtime to 25nsec, pumping was no issue anymore. definitively dead time was the culprit. the infineons end up much faster as the drive charge is so much less.

Best way to test for bus pumping is apply a low frequency sine wave.

 

[basreflex]

this was not the traditional LF pumping but the fets acting as stepup flyback converter, the bottom fet as the switch and the top fet as the diode. as there was no LF load the amp was idling into a high +rail of 100V.

 

[chienmort]

Any updates basreflex?

 

[mgshightech]

I am running an iraud350 I swapped the transistors for irfB4227 .. this runs hot and requires more heat sink. However, its driving a 2 ohm load with probably up to 600 watts and doesn't go into protection. Who knows, maybe this model is not using overcurrent protection. Now, I noticed you are running two boards ... guess what .. you may be having the issue that they are sharing a 0 volt line. If so, they may be interfering with each other .. remember that hf can get places in the circuit that normal frequencies can't get to and twiddle stuff up. When I ran a pair of L25Ds with same 0 volt line, it was much less stable than just running one. I haven't had the opportunity to try putting ferrite beads/ coils on the 0 volt line yet, but efforts to decouple the board from the power supply may help you if you have only a single power supply