Choosing capacitors for Laseractive PACs

So I've decided to finally order some capacitors for my aging laseractive PACs.
I've decided to go with new SMDs instead of through holes for the four PACs I own because I'm a sucker for punishment.
Since it's four PACs, three SEGA and one NEC it's close to 300 caps that I need and looking at Mouser I'm a bit at a loss on which to order. I mean I guess there is no point in ordering Aluminiumorganic polymer capacitors over ordinary electrolytic ones but what ESR should I go for?

I'm also going to have to do some trace and pad repair but that's going to be OK I think.

 

Why not order from console5. I have bought plenty of turboduo cap kits from them, I'd imagine your experience would be just as good as mine

 

Thats where mine came from. haven't installed them yet though. They are working on a kit for the actual console as well.

 

No mention of brand and since I live in Europe higher shipping charge, customs charge on it and then 25% VAT on top of it if I get unlucky.

 

You may have trouble converting all the caps to SMD ones due to the different footprints of the through hole caps.

I don't really look at ESR when choosing caps. Obviously lower is better but it also depends on value and stock available. Generally the polymer caps go down to really low esr with much higher lifespans but u are paying more for them. With 300 caps to buy, I can see this being an issue.

I just choose reputable companies like Panasonic, Sanyo, vishay and kemet when choosing either types of cap. It's cost a little more but u know u are getting quality.

Just make sure u match the tolerances of your caps as well.

Good luck.

 

It depends on how well you understand the design of the circuits and their accompanying components.

Replacing all 300 with electrolytic caps (with decent specs), after sorting through DigiKey, Mouser or Element14 (UK: Farnell) is one approach to save money, despite the time necessary to solder them all.

I wouldn’t recommend replacing all electrolytic caps with their polymer (electrolytic or tantalum) or hybrid capacitance equivalents – certain circuits will behave erratically with too little AC impedance and/or ESR. In other words, where five or more 100uF electrolytic caps are used to filter power, a single 100uF polymer or hybrid cap will do (and likely be overkill). This approach saves installation time, and likely money – but knowledge of the circuit and components is quite important.

 

Overall console5 isn't bad, but they didn't take the time to measure every cap to verify it would physically fit. Even caps of identical values cna sometimes be fatter or taller than others. I had this issue recapping some SEGA stuff with their kits. These days I just go to Digi-Key and get some Nichicon or Panasonic caps rated for 10k hours at 105C if it is economically feasible.

 

Wouldn't even need to measure, just use the info from the data sheets yes?

 

When he says measure, he's talking about the physical size of the original. You can have same value caps in different dimensions.

 

I think that was the point Leham was making. The physical size thing was a good thing to be reminded of, time to hit all those datasheets and grab my caliper for the boards I have not decapped yet.

 

You dont need to check datasheets - dimensions on the new ones should be available on any electronics suppliers product page (all the ones I order from, you can search by dimensions!).

Its the old ones you need to measure and is what APE was talking about. Almost all console schematics do not list the dimensions of the components. Its also far easier to measure a bunch of caps on a PCB than it is to look up a part number for each cap and then check its datasheet for dimensions. Its (generally!) only the diameter you care about for the most part anyway, once you get that right, the height generally follows as they come in standard sizes.

 

Don't do it. SMDs often have a poorer lifespan and it would be a complete nightmare actually getting them to physically fit. Plus they are more expensive.

Case in point....

Panasonic FR series 220uF 16V radial. 5000 hours @105 degrees. 6.3mm diameter, 5mm lead spacing. 16.5p each.

Panasonic TP series 220uF 16V SMD. 3000 hours @125 degrees. 8mm diameter. 86.2p each.

Yes, 3000 hours @125 degrees probably equates to 8000 @105, but would you really want to pay over five times as much for only 50% more lifespan? By the way, if all capacitors were the same price, then 300 would cost £200 MORE if you get SMD. Oh, and if that capacitor was a tight squeeze, your SMD component isn't even going to fit the space.... let alone getting it to mate to the contacts.

Get a decent brand, 105 degrees, good lifespan, low ESR (unless there's a specific purpose for certain capacitors). If you want to be super anal, then look up the ripple current of the old ones and go for at least that (or a high ripple current capacitor, anyway). Talking of which, the ripple current is almost double on the through hole example above.

 

Not really, electrolytic through-hole and SMD caps have excellent lifespans that aren’t dissimilar. Canned SMD caps can be easier to install and remove (twisting) than through-hole caps. An advantage in SMD caps over through-hole is better high frequency response/performance.

The through-hole cap (FR series) you mentioned is a standard part, and the SMD cap (TP series) is an automotive part (according to features section of datasheet)? If this is the case, then automotive parts are always more expensive, they are the cherry picked of standard parts.

The capacitor lifetime rating/de-rating is based on 10 C increments of sustained operation: every +10 C will halve the cap's lifetime, and every -10 C will double the cap’s lifetime. The SMD cap you mentioned should operate reliably for 3000 hours at 125 C, or ~12,000 hours at 105 C.

Source: http://fab.cba.mit.edu/classes/862.16/people/james.stowe/finalproj/parts/C6,C7.pdf

 

Usually, yes... although the ripple current rating is often lower. And they're only easier to install when the circuit board has been designed for them... they weren't designed as drop-in replacements for through-hole capacitors.

The TP series was the better spec capacitor for a similar price. They're not specifically automotive AFAIK (well, Panasonic marketed them for other applications, anyway), although are recommended for automotive applications. There's not an equivalent for anywhere near the radial price. The cheapest is an FK at 27p, which is 2000 hours at 105 degrees. The next one up is a TC at 75p, which is 3000 hours at 125 degrees. Literally all Panasonics between them in price are no better than the FK, lifetime-wise. The TP as a radial is really expensive, granted!

The reason for this is that SMD components are supposed to be ordered and used in bulk. Ordering a reel is much cheaper... but still not as cheap as a radial, usually!

True there. I was doing fast maths in my head... badly Of course, even 105 degree capacitors should last much longer than their rating, as it's highly unlikely your console will be running that hot!