Electronics Would it be a safe bet not to go near an 8000µ 42v capacitor..?

There's two of them inside my new amp...And I want to open it up so I can replace one of the LEDs that's dead. (The one that lights up the left channel's Wattage/Db analogue display.)

Any safe way of discharging them or should I not even risk it?

*n

PS: I've not opened it yet, Just seen them through the grille on top. It's a Pioneer SA-506.

 

I reckon they're probably pretty dangerous. Touching them with a screwdriver which has an insulator handle should sort it. Wait until someone else confirms this though, I'm not 100% sure.

 

They're about 30mm in diameter and 80mm high...

Certainly look imposing.

*n

 

Insulated screwdriver always does the trick

 

Hmmm,

C=Q/V I believe. So thats 0.32 coulombs of charge. Dunno if that's dangerous.

 

Certainly makes a bang, but is quite likely to cause permanent damage to the capacitor. Discharging with a resistor (most any value from around 200R to 1k) and checking with a multimeter is far safer.

At the end of the day, there's only 42v tops, so whatever the capacity it's not that dangerous.

Do you feel lucky, punk? Well, do ya?

 

E=0.5CV^2. About 0.71 joules, not too much. I wouldn't discharge it with a screwdriver because it may be very hard to remove it. As cpemma said, a resistor is the way to go. 360 ohms is the lowest value 1/8 watt resistor you could use.

 

I'm electronically retarded....more of the 'hit it 'til it works' approach...Based on fiddling with mechanical things

Can I pick up a suitible resistor from maplin and would it simply be a case of wearing rubber gloves and holding the ends of it to the points on the cap?

And I'm assuming that I'll be fine as long as I don't stick my tongue or wang in there....

*n

 

no no no...it is imperative that you DO stick your wang in there...and make sure you're mate comes and takes pictures...

EDIT: badgerbadgerbadgerbadgerbadgerbadgerbadgerbadgerMUSHROOMMUSHROOM!!!

 

I've a strong suspicion amp psu caps discharge when yur turn the power off, especially if something is playing at the time.

So yur precious is probably safe.

Pull the mains plug, u no it makes sense.

 

That it might have a bleeder resistor on it all ready, check it with a volt meter before you discharge it.

 

could explain why it'll continue playing for a couple of seconds after switching off...

*n

 

That's always a sign of good quality hi-fi equipment. Like when the power light takes about 5 minutes to go out on amps

Haha, wang is just the best word. It's filtering through all over the net, everyone's starting to use it

 

<HOMER SIMPSON>
Maude, the human wang is a beautiful thing
</HOMER SIMPSON>

 

WARNING : DO NOT SHORT THE CAPACITOR TO DISCHARGE IT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I accidently did that once, blew the tip off the multimeter probe and killed the cap.

Just unplug the power and wait till the amp stops going. Or if you are worried usea a resistor to discharge them. Anything over 20 ohms will be fine.

 

I'm still leaning toward wang/cap interaction....

*n

 

Watch it, you'll blow your nuts off

 

8000uF, 42v sounds like a low voltage cap, which shouldn't give you a shock, what you should look out for are the 200v or 400v high voltage caps.

 

Just leave it a couple hours (for piece of mind) it'll be fine.

 

You'll burn your wang