I have 3 different UcDs - a Hypex UcD 180, a Philips Demo PCB, and a home made through hole prototype.
One thing I have discovered is that for short circuit protection when the amplifiers are 'on', but with no input signal present, OVP is essential.
Obviously OCP doesn't really help in this situation, but on all 3 amplifiers the -ve supply goes crazy under short circuit conditions (it pumps more and more negative), and eventually the lower Mosfet will fail. The UcD 180 has been OK, because it has OVP, and my home made one is (mostly) OK now it has OVP, but the Philips board is well and truly dead!!
So, a big 'yes' to OVP IMHO
One thing I have discovered is that for short circuit protection when the amplifiers are 'on', but with no input signal present, OVP is essential.
Obviously OCP doesn't really help in this situation, but on all 3 amplifiers the -ve supply goes crazy under short circuit conditions (it pumps more and more negative), and eventually the lower Mosfet will fail. The UcD 180 has been OK, because it has OVP, and my home made one is (mostly) OK now it has OVP, but the Philips board is well and truly dead!!
So, a big 'yes' to OVP IMHO
hi class d from ru . wow i can,t believe i found this forum. i have made this amp using irf540n .at first it used to heat like crazy but i found the solution by changing resistor from 220r to 440r . your amp is powerful will post you pictures of my trials . i never got smd components and irfb fet because of my location will post pictures
hi luka it works fine,silent and very powerful .but i haven,t reached to over +/- 54vlts because of outputfets (i didnt find any bat or 1n58xx diodes so i just used the in4148) the best i can get was irf540n and irf640 they. used to heat insanely at first but when i changed resistor from to 220R to 440R all was fine
i don't have a scope to verify it but it works fine . the fets warm when operating at high volume levels . recently i found these fets irfb23n20 i will try them with +/- 90vlts hope i am in the right track.
i don't have a scope to verify it but it works fine . the fets warm when operating at high volume levels . recently i found these fets irfb23n20 i will try them with +/- 90vlts hope i am in the right track.
hi class d from ru ,luka and others here is my project based on this good amp but using non smd components ,totem pole parallel outputs
http://www.diysmps.com/forums/showthread.php?265-2-kwts-discreet-class-d-need-help/page16
http://www.diysmps.com/forums/showthread.php?265-2-kwts-discreet-class-d-need-help/page16
i'm using eagle 5.1 , also i'm stuck to irfp250n because of availability issues thats the best avail high powerfet for class d here . but i am a bit lucky there is a seller who has added irfb4229 to his stock.i'm planning to use them single +/-75vlts and will parallel 3 pairs for sub channel like +/-90vlts.
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