OK, I had a go at simulating back EMF from a 4mH (which seems 'normal', 40mH is a bit much) inductor with 5.5 ohm series resistance and a 56V supply. Worst case, driven from a FET being switched by a perfect square wave and 10R gate resistor, peak is 180V. So the TVS would clamp the worst of it, but still more than I'd like to subject a 150V device to.
Good news though, the expensive driver I want to protect is 0.9mH and 5.5 ohm, no crossover, so with a 63V supply it only kicks 70V.
Good news though, the expensive driver I want to protect is 0.9mH and 5.5 ohm, no crossover, so with a 63V supply it only kicks 70V.
Let's say we want belt and suspenders, we could connect two extra clamping diodes between speaker output and rails (as is done in some other protection circuits), which limits the maximum drain-source voltage to twice the rail voltage, even without TVS. Then with a 150V device there would be no risk of exceeding the maximum voltage rating, or am I wrong ?
That seems reasonable. Then the worst that could happen is that a diode fails s/c - which is how diodes generally fail, unless they actually explode - and stuffs a rail up the speaker, and the protection circuit has no effect.
Hi
Protection is rated for 150v but how much current can it handle?
I'd like to use it to protect pair of subs (2ohm load) with amp rated for 800w.
800w@2ohm is 40V and 20Amps, which is a lot of current.
Thanks for help
Protection is rated for 150v but how much current can it handle?
I'd like to use it to protect pair of subs (2ohm load) with amp rated for 800w.
800w@2ohm is 40V and 20Amps, which is a lot of current.
Thanks for help
Infineon BSC0402NSAT low RDson MOSFETs are rated for 80A. Should work fine.
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d462700c0ae6017015d4682a2212
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d462700c0ae6017015d4682a2212
Are these still available? I've been considering for some time such a device in my speakers.
Russellc
Russellc
Out of stock currently, but if there's enough interest, perhaps XRK will consider helping out us Greedy Boyz?
I'd be in for 6-10 boards depending on cost.
I'd be in for 6-10 boards depending on cost.
Ok, let us start an official interest list. Once we have 15 pairs of interest, I will ask you guys to place a pre-order and I can get production started again.
Pricing will be discouted to $100 per pair for folks doing pre-orders and then $125 per pair for those who do not preorder.
NAME / Qnty (pairs)
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
---------------------------
We are at 7 possibly 9 pairs so far. Need to get to 15 pairs.
Pricing will be discouted to $100 per pair for folks doing pre-orders and then $125 per pair for those who do not preorder.
NAME / Qnty (pairs)
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
---------------------------
We are at 7 possibly 9 pairs so far. Need to get to 15 pairs.
Ok, let us start an official interest list. Once we have 15 pairs of interest, I will ask you guys to place a pre-order and I can get production started again.
Pricing will be discouted to $100 per pair for folks doing pre-orders and then $125 per pair for those who do not preorder.
NAME / Qnty (pairs)
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
pgour / 2
Pricing will be discouted to $100 per pair for folks doing pre-orders and then $125 per pair for those who do not preorder.
NAME / Qnty (pairs)
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
pgour / 2
NAME / Qnty (pairs)
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
pgour / 2
Chermann / 6
mravinsky / 1
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
pgour / 2
Chermann / 6
mravinsky / 1
NAME / Qnty (pairs)
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
pgour / 2
Chermann / 6
mravinsky / 1
Arthur/ 4
---------------------------
chermann / 3
birdbox / 3 to 5?
rusellc / 1
pgour / 2
Chermann / 6
mravinsky / 1
Arthur/ 4
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