4 terminal capacitor is soldered wrong?

[primetime]

I'm servicing the amp on my subwoofer. Each of the two main AC capacitor filters(10mF 80V) have four terminals. The two capacitors are in series. I read the spec sheets on a different capacitor at Mouser and it stated that the two blank terminals should be isolated from either the positive or negative terminals. They are for mechanical support only. Yet, one capacitor has one of its blank terminals connected via a trace with its positive terminal and the negative terminal of the other capacitor. Is this a mistake in the design of the circuit board?

[TechGeek]

Re: 4 terminal capacitor is soldered wrong?

These seem to be 2-section electrolytic capacitors. Leave them connected as-is.

[budm]

Re: 4 terminal capacitor is soldered wrong?

I'm servicing the amp on my subwoofer. Each of the two main AC capacitor filters(10mF 80V) have four terminals. The two capacitors are in series. I read the spec sheets on a different capacitor at Mouser and it stated that the two blank terminals should be isolated from either the positive or negative terminals. They are for mechanical support only. Yet, one capacitor has one of its blank terminals connected via a trace with its positive terminal and the negative terminal of the other capacitor. Is this a mistake in the design of the circuit board?

Can we see good clear pictures of the caps and the circuit board?

[stj]

Re: 4 terminal capacitor is soldered wrong?

get the datasheet.
some have all the extra's connected to "-" and some say "dont connect"

[primetime]

Re: 4 terminal capacitor is soldered wrong?

View Me

I uploaded 3 pictures on OneDrive. I circled red the position of the two capacitors. I have not been able to find any info on the Soundia Capacitors. So I don't know if they are upto spec or not. But based on my measurements, capacitance is at 9mF, dissipation factor at 2.2, ESR at 100KHz is 0.3 Ω, ESR at 120Hz is 0.4 Ω. Both pretty much measure identically. Looking at spec sheets of Nichicon at Mouser, these Soundia's don't look too good.

It looks like I can use two lead capacitors, but will probably need to glue them down for support.

[stj]

Re: 4 terminal capacitor is soldered wrong?

in that aplication, the most important thing is the ripple current - you want the highest possible.

and that gets expensive,

[budm]

Re: 4 terminal capacitor is soldered wrong?

in that aplication, the most important thing is the ripple current - you want the highest possible.

and that gets expensive,

+1, They are just filter cap for +/- dual supply, one cap has NEGATIVE leg to circuit GND, and another cap has Positive leg to GND.

[primetime]

Re: 4 terminal capacitor is soldered wrong?

When I replace those caps should I solder them as before or should I cut the trace around that blank terminal?

[stj]

Re: 4 terminal capacitor is soldered wrong?

you are likely to get ones wih 2 terminals.
are the center holes 10mm apart? - if they are then it's for "snap-in" caps.

[kc8adu]

Re: 4 terminal capacitor is soldered wrong?

.4 esr on those is lousy.
bet you have hum issues.

View Me

I uploaded 3 pictures on OneDrive. I circled red the position of the two capacitors. I have not been able to find any info on the Soundia Capacitors. So I don't know if they are upto spec or not. But based on my measurements, capacitance is at 9mF, dissipation factor at 2.2, ESR at 100KHz is 0.3 Ω, ESR at 120Hz is 0.4 Ω. Both pretty much measure identically. Looking at spec sheets of Nichicon at Mouser, these Soundia's don't look too good.

It looks like I can use two lead capacitors, but will probably need to glue them down for support.

[primetime]

Re: 4 terminal capacitor is soldered wrong?

Yes, center holes are 10mm apart. I'd prefer to get a 4 legged capacitor if I have a choice since it adds extra anchor given the size of the capacitor and the 15" woofer that will be vibrating it. In fact one leg did break a solder joint.

The sub did have hum among other issues. Four other Soundia caps blown. I figured I'll replace all the Soundias.