yup.
the ones on the left are the replacements I got. the ones on the right are the ones that came off the amp. there aren't any signs that anyone went into that amp with a soldering iron before me so I'm thinking that these are originals.
the gate resistors are 100ohms and even if all measured correct, I still replaced them with the same value as I found some from scrap boards.
I'll try raising the dead time tomorrow and post what happens.
the ones on the left are the replacements I got. the ones on the right are the ones that came off the amp. there aren't any signs that anyone went into that amp with a soldering iron before me so I'm thinking that these are originals.
the gate resistors are 100ohms and even if all measured correct, I still replaced them with the same value as I found some from scrap boards.
I'll try raising the dead time tomorrow and post what happens.
I replaced the 48.7kohm resistor in the upper deadtime voltage divider network with 39kohm and there is still slight heating so I went lower with 27kohm and there is considerably much less heating than before bit it still gets just perceptibly warm. I think I'll stay with that one.
although heating is reduced, idle current draw is the same.
although heating is reduced, idle current draw is the same.
I rewound the output inductor again thinking that I didn't do it properly . I laid the wires neatly on the core while it was scramble wound previously.
I used more turns than before so it ended up at 109uH (79uH before) and current draw at idle dropped to 2.4A. after the inductor, I get a triangle wave with rounded sides at 2Vpk-pk. residual at output terminals also reduced to 0.2Vpk-pk.
I'm not sure if it is running cooler as it is just a quick test and I tested it with the inductor not yet saturated with varnish. it did get really warm but not burning hot with about a minute of run time. I couldn't do a longer run time as it wasn't installed in the heatsink.
I used more turns than before so it ended up at 109uH (79uH before) and current draw at idle dropped to 2.4A. after the inductor, I get a triangle wave with rounded sides at 2Vpk-pk. residual at output terminals also reduced to 0.2Vpk-pk.
I'm not sure if it is running cooler as it is just a quick test and I tested it with the inductor not yet saturated with varnish. it did get really warm but not burning hot with about a minute of run time. I couldn't do a longer run time as it wasn't installed in the heatsink.
went around in micrometals site and they indicated a brown/black painted core is one of their high temp cores.
AL value is supposed to be 65. mine is only 43. either it is different or the core got cooked so much when it burned.
if I used the micrometals core, it should be 125uH with the original number of turns if I calculated right.....
does anyone know where I could get that core T150-60 that ships to here?
http://www.micrometals.com/material/index-60.html
edit:
although I have these coming my way and I think I might be able to use a couple stacked on each other......
AL value is supposed to be 65. mine is only 43. either it is different or the core got cooked so much when it burned.
if I used the micrometals core, it should be 125uH with the original number of turns if I calculated right.....
does anyone know where I could get that core T150-60 that ships to here?
http://www.micrometals.com/material/index-60.html
edit:
although I have these coming my way and I think I might be able to use a couple stacked on each other......
my LC meter can't measure anything above 1uF so I can't check. I didn't notice it get warm but it was just a quick run though so I'm not 100% sure that it is good.
once the varnish dries I'll reinstall everything again into the heatsink to test run for longer periods.
I'll check it again once I resolve the problem with the inductor. if it is bad and I can't find a replacement, I have a couple of 4.7uF film caps I could parallel that I might be able to graft into it.
once the varnish dries I'll reinstall everything again into the heatsink to test run for longer periods.
I'll check it again once I resolve the problem with the inductor. if it is bad and I can't find a replacement, I have a couple of 4.7uF film caps I could parallel that I might be able to graft into it.
varnish has dried so I installed the inductor again.
I only ran it idling to check the inductor. test run was about 4minutes continuous and in that period, the inductor got rather hot. somewhere around 60-70C.
the 10uF cap got to about 35C I'm guessing it was only getting hot because it is right beside the hot inductor.
when the inductor core got hot, I noticed idle current was also increasing. if I went further with the test, I fear it will result to something similar to thermal runaway.
so my conclusion is that the inductor core is toast so a replacement is necessary.
work will continue when the MPP cores arrive.
thanks for all the help, Perry.
I only ran it idling to check the inductor. test run was about 4minutes continuous and in that period, the inductor got rather hot. somewhere around 60-70C.
the 10uF cap got to about 35C I'm guessing it was only getting hot because it is right beside the hot inductor.
when the inductor core got hot, I noticed idle current was also increasing. if I went further with the test, I fear it will result to something similar to thermal runaway.
so my conclusion is that the inductor core is toast so a replacement is necessary.
work will continue when the MPP cores arrive.
thanks for all the help, Perry.
a little update:
well, the MPP cores are taking a bit longer than expected to arrive so I tried something else since I had nothing better to do....
looking at at micrometals site, two T106 cores have a total cross section area of about 1.318cm^2 and total volume of 8.56cm^3 compared to the original core of 0.887cm^2 area and 8.31cm^3 volume and I used hi-flux cores which are rated to operate at up to 200degC and higher flux capacity than the original cores. but they have a max rating of 100kHz for pure inductor applications. but switching freq is about 77kHz so I think it should still work....
I wound 22turns on two stacked cores ending up with about 177uH thinking that the higher initial inductance might help with the residual at the output and reduced inductance at higher currents and higher temps.
idle current is about 1.7amps. residual at output is 0.08Vpk.
the only issue I'm having is that at about 15min run at low volume, the inductor gets to 88degC (with temp probe in middle of toroid, top cover installed). temp is still increasing but nearly stabilizes.
edit: idle current is stable at about 1.65A with the inductor running hot at 92degC
edit #2: idle current is still the same. inductor at 98degC. heatsink is warm. ambient temp is 27degC.
besides that, sound is good and main heatsink never got warm.
well, the MPP cores are taking a bit longer than expected to arrive so I tried something else since I had nothing better to do....
looking at at micrometals site, two T106 cores have a total cross section area of about 1.318cm^2 and total volume of 8.56cm^3 compared to the original core of 0.887cm^2 area and 8.31cm^3 volume and I used hi-flux cores which are rated to operate at up to 200degC and higher flux capacity than the original cores. but they have a max rating of 100kHz for pure inductor applications. but switching freq is about 77kHz so I think it should still work....
I wound 22turns on two stacked cores ending up with about 177uH thinking that the higher initial inductance might help with the residual at the output and reduced inductance at higher currents and higher temps.
idle current is about 1.7amps. residual at output is 0.08Vpk.
the only issue I'm having is that at about 15min run at low volume, the inductor gets to 88degC (with temp probe in middle of toroid, top cover installed). temp is still increasing but nearly stabilizes.
edit: idle current is stable at about 1.65A with the inductor running hot at 92degC
edit #2: idle current is still the same. inductor at 98degC. heatsink is warm. ambient temp is 27degC.
besides that, sound is good and main heatsink never got warm.
that's what I thought. I could try a triple stack but it will end up too high and will not fit in the case and I ran out of #18 wire.
with a bit of airflow on the top cover, temp stabilizes at 97degC.
idle current is still the same.
residual at output is really low since it has a 4th order filter.
I have to install it in the car for full power testing but I don't have a big enough sub to take this much power. I already sold my big subs. I only have a single 10" left.
with a bit of airflow on the top cover, temp stabilizes at 97degC.
idle current is still the same.
residual at output is really low since it has a 4th order filter.
I have to install it in the car for full power testing but I don't have a big enough sub to take this much power. I already sold my big subs. I only have a single 10" left.
Hi
I still have 2512a, just to say I ain't going off from DD ever , only up in size and class, now I'm on 3515d...I think I will stay here for long time, this sub is crazy and I don't think I even push it with 1kw... you got to get one of this...but I guess 15" are out, only 10" and 12". Maybe you should go for 3x 1508 or something like that...see this and one with 2512a
If you would make box with slot port something like I did , it will kick as hell
I still have 2512a, just to say I ain't going off from DD ever
, only up in size and class, now I'm on 3515d...I think I will stay here for long time, this sub is crazy and I don't think I even push it with 1kw... you got to get one of this...but I guess 15" are out, only 10" and 12". Maybe you should go for 3x 1508 or something like that...see this and one with 2512aIf you would make box with slot port something like I did , it will kick as hell
Hi
I wouldn't believed it if I wouldn't have it. Where in most subs you have to look at RMS value so that you don't destroy sub, you have to look at music power with DDs. Friend of mine put good 2kw on 2515a it was short time only 10s but sub toke that power. Ofcourse he did blow that speaker later on when he pushed it several minutes with that power. Read forums about DD speakers... also I like FI ,but I probably couldn't get them here...and they are cheap compared with how good they are
I wouldn't believed it if I wouldn't have it. Where in most subs you have to look at RMS value so that you don't destroy sub, you have to look at music power with DDs. Friend of mine put good 2kw on 2515a it was short time only 10s but sub toke that power. Ofcourse he did blow that speaker later on when he pushed it several minutes with that power. Read forums about DD speakers... also I like FI ,but I probably couldn't get them here...and they are cheap compared with how good they are
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