Yes I do. I took some to send to Perry and he was sorta lost with it, and quite frankly, So am I.
Works fine, but when you give it volume the driver board clips out. and causes the sub to crackle. Only the driver is clipping out, and not the output stage. Tracked it down to that goofy DLI4060B. And I never liked dlogix junk anyway.
Scope shots confirmed it was crackling becuase it was bumping into 100% modulation, or driver clipping early. But it just wasnt loud. I cant really explain it.
So id rather just replace the driver with a better one.
Works fine, but when you give it volume the driver board clips out. and causes the sub to crackle. Only the driver is clipping out, and not the output stage. Tracked it down to that goofy DLI4060B. And I never liked dlogix junk anyway.
Scope shots confirmed it was crackling becuase it was bumping into 100% modulation, or driver clipping early. But it just wasnt loud. I cant really explain it.
So id rather just replace the driver with a better one.
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Oh BTW. the first problem with this thing it was latching the outputs fully on. With no oscillation, of course, this was dropping the rails to near 0 and pulling an insane amount of current, plus getting 100 degrees within seconds on the heatsink.
That was the initial problem. After pulling the board and checking everything, removing the driver, checking it, and reinserting it that problem went away. But this problem resides. So yea, something isnt right.
That was the initial problem. After pulling the board and checking everything, removing the driver, checking it, and reinserting it that problem went away. But this problem resides. So yea, something isnt right.
Checked those, and there are 2 level shifter transistors in between the 4 zeners and I went ahead and replaced those just to be on the safe side. They are ok.
I clipped all 4 zeners and did a clamping voltage test, and they are ok. they are 7.5v and 10v zeners. in pairs.
Another thing is in order to get the subwoofer producing a good amount of volume, the gain is almost all the way up and thats when it begins clipping.
So the pre-amp stage and even the modulator might be alright, as the scope indicated that its swinging over 100% modulation which is why its clipping out.
but there is just no volume. it should be maybe 4 times louder on the sub than what it is. Rails are stable at 70V and are NOT sagging.
it uses IRF640 and IRF9640 as outputs. the IRF640 side unclamped does get quite warm in operation. the 9640 side stays nice and cool.
I clipped all 4 zeners and did a clamping voltage test, and they are ok. they are 7.5v and 10v zeners. in pairs.
Another thing is in order to get the subwoofer producing a good amount of volume, the gain is almost all the way up and thats when it begins clipping.
So the pre-amp stage and even the modulator might be alright, as the scope indicated that its swinging over 100% modulation which is why its clipping out.
but there is just no volume. it should be maybe 4 times louder on the sub than what it is. Rails are stable at 70V and are NOT sagging.
it uses IRF640 and IRF9640 as outputs. the IRF640 side unclamped does get quite warm in operation. the 9640 side stays nice and cool.
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I isolated the scope grounds, and tested the drive signal DC-coupled between gate and souce of the IRF640.
I get a square wave like before, but its between -7.5v on the low and +10v on the high.
I would figure that the signal would swing between 0v and +20v. not -7.5v and +10v
But thats what I got. IT kinda make sense because the zeners are rated for 7.5v and 10v.
the IRF9640 signal is the opposite. its +7.5v and -10v
I get a square wave like before, but its between -7.5v on the low and +10v on the high.
I would figure that the signal would swing between 0v and +20v. not -7.5v and +10v
But thats what I got. IT kinda make sense because the zeners are rated for 7.5v and 10v.
the IRF9640 signal is the opposite. its +7.5v and -10v
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Yes it does ;-) I even ring checked the inductors, and then measured the inductance of each one, and they were equal. I absolutely could not find anything wrong in the output section. it just has no volume hardly, even though the gate drive is swinging into 100% modulation.
it just doesn't make any sense whatsoever. maybe the modulator is bad and I cant really tell?
the only thing I have not done is pulled each and every electrolytic and checked them individually. But in-circuit I am reading roughly the correct parallel capacitance and a good ESR.
if I remember correctly I think i was getting maybe 16 or 17VAC into the 4ohm load with 100% gate modulation. I had full rail voltage in AC at the filter coil from the MOSFETs, which basically tells me that the square-wave output signal going into the output filter is at full potential.
I mesured the blue box output filter caps, and I got a capacitance reading that is equal to all the blue box caps added together. So none are open.
Edit: You know what, now that I am thinking about it. I measured the VAC at the point where it goes into the output filter, and got 60VAC thereabouts. Thats approximately equal to 1 side of the rails. Shouldn't the output in AC be equal to both the positive AND negative rails? so 120VAC?
I got correct gate drive at both the high side and low side of the mosfets, and got correct negative and positive rail voltages at each side.
But since I cannot obviously isolate the grounds between the 2 scope channels, I cant hook both drives up at the same time and see what the dead-time is. maybe its too great.
it just doesn't make any sense whatsoever. maybe the modulator is bad and I cant really tell?
the only thing I have not done is pulled each and every electrolytic and checked them individually. But in-circuit I am reading roughly the correct parallel capacitance and a good ESR.
if I remember correctly I think i was getting maybe 16 or 17VAC into the 4ohm load with 100% gate modulation. I had full rail voltage in AC at the filter coil from the MOSFETs, which basically tells me that the square-wave output signal going into the output filter is at full potential.
I mesured the blue box output filter caps, and I got a capacitance reading that is equal to all the blue box caps added together. So none are open.
Edit: You know what, now that I am thinking about it. I measured the VAC at the point where it goes into the output filter, and got 60VAC thereabouts. Thats approximately equal to 1 side of the rails. Shouldn't the output in AC be equal to both the positive AND negative rails? so 120VAC?
I got correct gate drive at both the high side and low side of the mosfets, and got correct negative and positive rail voltages at each side.
But since I cannot obviously isolate the grounds between the 2 scope channels, I cant hook both drives up at the same time and see what the dead-time is. maybe its too great.
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