http://www.mouser.com/ds/2/149/FDP083N15A-348290.pdf
Im planning to build a relay for speaker protection but i was quite doubtful about its ratings for speaker relay application considering the Vds while working as relay will be very low but looking at the pin of TO220 package will it be really able to deliver 70 to 80Amps? I think the die will do it but what about the pins?
There is another mosfet with https://www.infineon.com/dgdl/irfp4668pbf.pdf?fileId=5546d462533600a40153562c8528201d
My application is to use it for either power supply cuttoff for 8 pairs of MJL21193/94 or to use it as speaker relay
looking at conventional fuses I see even for a 20Amp the fuse wire is not much thicker so will these terminals of TO 220 and TO 247AC able to handle currents in the order of 30Amp peak or more?
Im planning to build a relay for speaker protection but i was quite doubtful about its ratings for speaker relay application considering the Vds while working as relay will be very low but looking at the pin of TO220 package will it be really able to deliver 70 to 80Amps? I think the die will do it but what about the pins?
There is another mosfet with https://www.infineon.com/dgdl/irfp4668pbf.pdf?fileId=5546d462533600a40153562c8528201d
My application is to use it for either power supply cuttoff for 8 pairs of MJL21193/94 or to use it as speaker relay
looking at conventional fuses I see even for a 20Amp the fuse wire is not much thicker so will these terminals of TO 220 and TO 247AC able to handle currents in the order of 30Amp peak or more?
Im just calculating the idea of using wire guage with fusing current capability as per the are of the cross section. Fusing Currents versus American Wire Gauge for copper, aluminum, iron, and tin (Cu, Al, Fe, Sn), wire melting currents
As per that the TO 220 typical package will fuse at about 41.5Amp and TO 247 pins will be able to handle about 117A to 140A max as per the ratings. Please correct me if im wrong here.
some more supporting posts How can MOSFET pin (legs) handle the current? | All About Circuits
As per that the TO 220 typical package will fuse at about 41.5Amp and TO 247 pins will be able to handle about 117A to 140A max as per the ratings. Please correct me if im wrong here.
some more supporting posts How can MOSFET pin (legs) handle the current? | All About Circuits
80 amps!
The wire tables derive I think from the 3 wires in a conduit at 105 deg C tests. So there is some leeway for heatsinked parts in front of a fan.
I've been worrying about how to use an FDP52N20 at 22 amps supplying rail current to 5 pairs of MJ21193/94. Not having a supplier to deliver extra thick board lands, or even boards at all, I've been planning to use 3M crimp terminals. The .250 spade lugs are rated at 30 amps. I've melted ****ese RS spade terminals at that current, on the back of my car ignition switch. Whereas Ideal brand (no longer sold) worked fine. I think 3M and Thomas & Betts terminals are as good as ideal, the barrels are certainly thicker than ****ese terminals.
I'm going to bend the TO220 legs, crimp pink spades on, fill with solder, bend back flat. Mount the FETs on a heat sink even though the datasheet doesn't seem to need that . Then use yellow shaft female spades on the 10 ga wire from the 10000 uf cap. Also on to the .250 spade on 10 ga wire to the output transistor board.
Of course we could buy SS relays with big screws on them for $60 and let the builder worry about it. But it is hard to sort out the triac "relays" from the fet "relays" when you buy onesies.
The wire tables derive I think from the 3 wires in a conduit at 105 deg C tests. So there is some leeway for heatsinked parts in front of a fan.
I've been worrying about how to use an FDP52N20 at 22 amps supplying rail current to 5 pairs of MJ21193/94. Not having a supplier to deliver extra thick board lands, or even boards at all, I've been planning to use 3M crimp terminals. The .250 spade lugs are rated at 30 amps. I've melted ****ese RS spade terminals at that current, on the back of my car ignition switch. Whereas Ideal brand (no longer sold) worked fine. I think 3M and Thomas & Betts terminals are as good as ideal, the barrels are certainly thicker than ****ese terminals.
I'm going to bend the TO220 legs, crimp pink spades on, fill with solder, bend back flat. Mount the FETs on a heat sink even though the datasheet doesn't seem to need that . Then use yellow shaft female spades on the 10 ga wire from the 10000 uf cap. Also on to the .250 spade on 10 ga wire to the output transistor board.
Of course we could buy SS relays with big screws on them for $60 and let the builder worry about it. But it is hard to sort out the triac "relays" from the fet "relays" when you buy onesies.
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in think in that case I would use IRFP4668 with 5 pairs of 21193/94. I think i would do the same way of adding some lug and then lead over the drain and source pins.
But I think they should have taken the load? what is the peak current which is flowing through the FDP52N20 22 amps?
But I think they should have taken the load? what is the peak current which is flowing through the FDP52N20 22 amps?
wire heating is rms amps. I'm protecting a PV-1.3k which has 2 ohm rating of 1000 w. sqrt 500 is 22.6 a. I realize speaker are more inductive and have higher current than resistors, but I think 30 a rated crimp terminals should be adequate. fdp52n20 fet resistance is .04 so fet heating is 36 w at 30 a, surely within the capability of a heat sinked To220 part in front of a 5" fan. I've got the FDP52n20 already, $1.20 each.
I've also got 30-40 IXTK62n25 salvaged from a 50" LED television I found on the curb, but cramming two heatsinks that fit those TO264 parts wouldn't conveniently fit in the spare space I've got between rail cap board and output transistor board. Those latter are are 62 a rated .035 ohm 250 v rated parts. I think the FDP52n20 should be adequate. mazing what treasures people throw away, just because of some blown power supply electroltytic caps.
I've been putting the FET assembly on this off for two years. I don't really need 1300 w, I played wood piano for a crowd of 100 people today, about my maximum. I bought a panavise last month that makes soldering something as fragile as a fet maybe doable. Previously I held a vise grip pliers between my knees.
I've also got 30-40 IXTK62n25 salvaged from a 50" LED television I found on the curb, but cramming two heatsinks that fit those TO264 parts wouldn't conveniently fit in the spare space I've got between rail cap board and output transistor board. Those latter are are 62 a rated .035 ohm 250 v rated parts. I think the FDP52n20 should be adequate. mazing what treasures people throw away, just because of some blown power supply electroltytic caps.
I've been putting the FET assembly on this off for two years. I don't really need 1300 w, I played wood piano for a crowd of 100 people today, about my maximum. I bought a panavise last month that makes soldering something as fragile as a fet maybe doable. Previously I held a vise grip pliers between my knees.
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The die attach bonds vaporize before the pins on a typical TO220 or TO247 package.
In a solid state speaker relay you will only conduct faulty level currents for a few milliseconds in any event worst case.
On my amps, I test each channel with a >60 Amp 10 ms pulse. The SSR disconnects the loudspeaker after 100 us. The mosfet (TO220) is rated at 85 Amps and I have never had a failure.
Don’t second guess manufactures data sheet ratings. The mosfet you are looking at says 117 amps continuos and 480A peak. A company like Fairchild (now On) would not publish data like that unless it was quite confident the device met the specification.
In a solid state speaker relay you will only conduct faulty level currents for a few milliseconds in any event worst case.
On my amps, I test each channel with a >60 Amp 10 ms pulse. The SSR disconnects the loudspeaker after 100 us. The mosfet (TO220) is rated at 85 Amps and I have never had a failure.
Don’t second guess manufactures data sheet ratings. The mosfet you are looking at says 117 amps continuos and 480A peak. A company like Fairchild (now On) would not publish data like that unless it was quite confident the device met the specification.
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70 to 80 Amps??
I have in mind a 600 Watt 8r amp. Needs 200V 4A power supply, peak current 12 Amps.
If built as Bridge it wants 100V 8A and still 12A peak.
I don't think you get close to 70A unless you run super low impedances or try to run a lot of channels on one MOSFET.
> The wire tables derive I think from the 3 wires in a conduit at 105 deg C
That particular table is (as it says) Fusing (melting) current in free air.
Check: in house wiring #12 is good for 20-25A, #6 for 50-60A. Table says 235A and 668A!! This is clearly not "conduit" rating.
And as said, someone took the data in the sheet, it is probably valid.
But look at the SOAR fig 9. If you start at 100V while interrupting 100A, you better switch in less than 10uSec. This is above the audio range. You will need a Power gate driver to slam the thousands of pFd gate capacitance that fast.
I have in mind a 600 Watt 8r amp. Needs 200V 4A power supply, peak current 12 Amps.
If built as Bridge it wants 100V 8A and still 12A peak.
I don't think you get close to 70A unless you run super low impedances or try to run a lot of channels on one MOSFET.
> The wire tables derive I think from the 3 wires in a conduit at 105 deg C
That particular table is (as it says) Fusing (melting) current in free air.
Check: in house wiring #12 is good for 20-25A, #6 for 50-60A. Table says 235A and 668A!! This is clearly not "conduit" rating.
And as said, someone took the data in the sheet, it is probably valid.
But look at the SOAR fig 9. If you start at 100V while interrupting 100A, you better switch in less than 10uSec. This is above the audio range. You will need a Power gate driver to slam the thousands of pFd gate capacitance that fast.
The max current to start with will be the power supply voltage divided by DC resistance of speaker. Then as speaker voice coil resin melts and shorts it could go down to zero ohms and pass as much current as supply can manage.
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