User error! I accidentally dropped my screwdriver while adjusting VR2. Afterward I managed to find about 20 irl2910s on Arrow.com. Now it appears Arrow.com no longer stocks them. I currently have huf76639S3s installed that I converted from TO-263 to TO-220. To be cautious, I consider my setup experimental and would not recommend it.
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Hello,
49.5 ohms is close enough
. Thanks for the photos. You can see that in the Right channel: R128 and R144 were burnt. It’s hard to tell if R28 R44 are also burnt in the Left channel. I would replace all 4 to be safe. Part number: ER58R33JT. I bought them on Mouser.
Which fuses broke, if any?
Next I would spot check resistors, transistors, and diodes that are close in circuit to the output devices. Check L versus R. For example, ZD6(106), ZD7(107). You can diode check the transistors. If one of the two damaged you’ll see a different diode reading in the L vs R channel. For example, Q0(100). Check as much as possible. Better to over check. On the other hand, in the past I have replaced all those closer components since they’re not that expensive and I’m already in the area replacing the output devices and R28/128 and R44/144.
49.5 ohms is close enough
. Thanks for the photos. You can see that in the Right channel: R128 and R144 were burnt. It’s hard to tell if R28 R44 are also burnt in the Left channel. I would replace all 4 to be safe. Part number: ER58R33JT. I bought them on Mouser.Which fuses broke, if any?
Next I would spot check resistors, transistors, and diodes that are close in circuit to the output devices. Check L versus R. For example, ZD6(106), ZD7(107). You can diode check the transistors. If one of the two damaged you’ll see a different diode reading in the L vs R channel. For example, Q0(100). Check as much as possible. Better to over check. On the other hand, in the past I have replaced all those closer components since they’re not that expensive and I’m already in the area replacing the output devices and R28/128 and R44/144.
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I’m glad to hear you found some IRL2910s. and the resistors are inbound. I put a small book under the IRL2910s to align the height of the case with the aluminum bar that secures them to the heat sink.
Are you using the Mica or silicone pad? I would use very little grease for silicone pad. Double check for shorts (IRL2910 Drain to heat sink) after fastening the metal bars. I lost a HUF76639 because
the pad didn’t completely cover the drain!
Once you power up, the idle voltage should be very low around 0.3mV. The idle voltage will increase very very slowly until around 1-2mV. Then increase more sharply until you reach 21.5mV.
Let me know if you have any questions.
Looking forward to hearing how it goes and sounds.
Are you using the Mica or silicone pad? I would use very little grease for silicone pad. Double check for shorts (IRL2910 Drain to heat sink) after fastening the metal bars. I lost a HUF76639 because
the pad didn’t completely cover the drain!
Once you power up, the idle voltage should be very low around 0.3mV. The idle voltage will increase very very slowly until around 1-2mV. Then increase more sharply until you reach 21.5mV.
Let me know if you have any questions.
Looking forward to hearing how it goes and sounds.
I’m not familiar with ceramic pads. Which ones? I know Mica or Sil-pads will work fine. Likely ceramic pads are fine as long as they conduct heat well, insulate electrically. The grease helps a fill gaps between the mosfet, pad and heat sink. In my opinion the type of pad isn’t that critical because the temperature change isn’t so high. My heat sinks are usually around 40C.
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Depends on the ceramic in question. AlN is excellent, Al2O3 is so-so, BeO is excellent but has toxicity issues if damaged as the dust is poisonous and carcinogenic if breathed/ingested, and C(diamond) is the best by a long way other than price(!). BeO is nearly as good as copper, diamond is way better, AlN is comparable to various metals. BTW mica is very poor by comparison to any of these ceramics, it was only ever used because it cleaves into thin sheets readily.
Hi, I don't have new resistors yet😒 . You wrote to me that after switching on, the idle voltage should be very low, about 0.3 mV. The idle voltage will increase very slowly, up to about 1-2 mV. Then I increase it more rapidly until I reach 21.5 mV. Should I change the resistance on VR1 to make it 21.5mV? . And I don't know where to measure the voltage of 21.5 mV with a meter 🤔