Looking for speaker DC protection ideas..

[Viitalahde]

[quote author="mhelin"]I would use a high quality cap in series of the tweeter and midrange.[/quote]

I gave some thought to this, and then forgot about it. Let's calculate again..

Assuming 8 ohms loads for mids & tweeters (with the impedance peaks at resonance points taken into accound), a corner frequency at least two octaves below cross-over points is going to be needed.

Tweeter = 47uF to get way below the resonance point
Midrange = 200uF for flat two octaves under 380Hz.

I've got to think of this. In any case, having a capacitor in series with the tweeter is probably not going to be as bad as having a power relay.

[quote author="Gold"]I know it's not in the spirit of the thread but why not just throw caution to the wind and in the unlikely event of catastophic failure buy a new driver.[/quote]

You got a point there. I've never actually heard of failures with UcD modules so I'm really preparing for the very rare case here.

I am going to implement a DC protection circuit that cuts off the rails when DC is detected. This should give a pretty good protection.

...

Lamps? Fuses? I've understood the sizing is pretty critical, and they're not maintenance free.

 

[Viitalahde]

**** it, I'm going for the capacitors. The simplest and most fool-proof solution.. :razz:

 

[mhelin]

[quote author="Viitalahde"]
**** it, I'm going for the capacitors.
[/quote]

How about if you integrated the protection cap into the crossover network?

Lamps? Fuses? I've understood the sizing is pretty critical, and they're not maintenance free.

Lamps (bulbs) compress sound (are not constant), fuses are maybe too slow (they sense current not voltage).

 

[Viitalahde]

[quote author="mhelin"]How about if you integrated the protection cap into the crossover network?[/quote]

Thought about it, but then again you'd need to go for LCR circuits for the impedance peaks, etc.. Soon we'd be ruining the whole idea of having an active cross-over in the first place.

I'm not completely dismissing the idea yet, though.

 

[CJ]

Slo Blo fuse.

Jako, think of how many woman you could have banged in the time you spent being paranoid over your "next big thing" speakers

You can never get those shagged ho's bak, and a ho a day keeps the doctor away, what say?

 

[JohnRoberts]

Fuses, light bulbs, etc often had negative impact on signal integrity so for personal use where you don't abuse your system their benefit may not outweigh the cost.

JR

 

[Viitalahde]

[quote author="CJ"]a ho a day keeps the doctor away, what say?[/quote]

Bangin' hoes only gives you a severe case of Pimmel-Schimmel. :razz:

I've pretty much made up my mind. Capacitors on mid + tweeter, and most likely also relays for taking the rails out in case of a failure.

 

[CJ]

IF YOU HAVE KIDS OR DRUNKEN OR STONED GUESTS, ITS BEST TO HAVE EVERYTHING "CHILDPROOF"

sorry kurt, caps off.

but nobody round here is makin babies, they got an iron in one hand, and a cancerous, puss dripping, herpes infested schlong in the other. so that just leaves drunken or stoned guestd, and if you surf this forum as much as i do,, you are probably sociallilogically disfunctional and lonely with no guests so all you have to do is worry about yourself.

just match the amp with the speakers, so that the amp knob can sit on ten all day while you are at work, and the spk does not pop.

and build the pwr xfmr so that if a rail shorts, the dcr of the sec winding will limit current until a fuse pops on the primary,



but lots of diy gear so i guess thats cool, cause that stuff stays round longer than the ho's , unless you get taken to small claims, so buy an engraver and mark all your cool gear on the back and inside, excuse me, what was the question?

 

[mr coffee]

CJ,

You had me laughin' my ass off!!!!

Damn, ... and a comedian, too!

You da man !!! :thumb:

 

[Guest]

Viitalahde;

If I heard some question but feel that I have no optimal answer I continue thinking on it in background.
Today I come across a TA7291 chip from Toshiba. It may be used to control an electromagnetic relay really fast
Leave high level on one input pin, and control the other one. The advantage is, it switches off the rely really fast
May be I am wrong: it is 6.53am, I could not asleep because of a tooth pain, but the idea seems to be good!

 

[mikep]

how about relays, but with caps bypassing the contacts?