I have an amp with some issues needs addressing…the PIC controller is malfunctioning resulting in the power pwm keeps pulsing on and off, I’ve modded a direct drive circuit thus keeping the power supply on (module was taken from a JBL amp riser pwm card) IRF1404 was used with 10ohms resistors. That worked but my power led flashes alternating with clip led and protect led (it played regardless as I assumed the malfunctioning PIC.
The customer brought back the amps after many months of continued flawless working, this time two outputs are bad thus taking out the power FETs. I don’t know what sub to use in the output side as they are scruffed and etched with C2 on them (currently I’m trying some IRF640’s which seems to play and seems cool) can anyone make any other suggestions for output selection for this amp? The audio drivers are IRS2092S scruffed as C7.
The customer brought back the amps after many months of continued flawless working, this time two outputs are bad thus taking out the power FETs. I don’t know what sub to use in the output side as they are scruffed and etched with C2 on them (currently I’m trying some IRF640’s which seems to play and seems cool) can anyone make any other suggestions for output selection for this amp? The audio drivers are IRS2092S scruffed as C7.
Does anyone knows what the originals are? ive tried using the IRFB4321 and they were getting warm on another amp but i did have the same "C2" and when replace they ran cool. I've use the IRFB's on more rugged design (one channel version with higher rail voltages) they ran good on those.
How did the drive compare between the amps where they ran hot and ran cool?
Gate resistors?
Rail voltage?
Parallel pull-down resistor on gate resistor?
Same driver IC?
Gate resistors?
Rail voltage?
Parallel pull-down resistor on gate resistor?
Same driver IC?
It was same model amp, had about three of them to ran experiment on, thats how i derived at the PIC controller was bad, had access to swap all the suspected component and it still wouldnt switched on until i changed the PIC. Then i ran IRFB4321 and they werent normal temperature as the masked one on the output, but when replace with the ones mark C2 from the experiment, they ran cooler. As i said i always used the recommended replacement subs in the larger amps and now worries, and ive used the 640's in these design and never had a issue as far as output failure before.
My concern however if theres anyone knows what exactly are the masked ones (could they be HY3210)?
My concern however if theres anyone knows what exactly are the masked ones (could they be HY3210)?
Have you tried all of the others suggested?
If you have them, compare the gate drive signal of them to the IRF640s to see if the shape of the gate drive signal compares for those that run hotter/cooler and then see if that relates to the Qg and Ciss of the various FETs.
If you have them, compare the gate drive signal of them to the IRF640s to see if the shape of the gate drive signal compares for those that run hotter/cooler and then see if that relates to the Qg and Ciss of the various FETs.
