Router Recap

[benrp]

Hi.

I hope you can help me choose some replacement caps for my router.

The original capacitors are:

Lelon 100uf 10v RZW - 0.58 impedance, 210 ripple
Lelon 220uf 16v RJA - unknown impedance, 180 ripple
3x Lelon 470uf 10v RXJ - 0.25 impedance, 410 ripple
Lelon 1000uf 16v RXK - 0.052 impedance, 1112 ripple


I was thinking of replacing all of them with Panasonic FR series:

100uf 10v - 0.3 impedance, 280 ripple
220uf 16v - 0.13 impedance, 455 ripple
470uf 10v - 0.056 impedance, 950 ripple
1000uf 16v - 0.03 impedance, 1560 ripple


Will the lower impedance and higher ripple of the Panasonics be a problem?

Thanks in advance.

[mariushm]

Re: Router Recap

There won't be any problems due to lower impedance , but you might want to double check the height before buying.

FR series is not optimized for size, FM series is often a bit smaller in height.

[benrp]

Re: Router Recap

Thanks for the advice.

I checked the height and I should be ok except for the 1000uf cap. I can get a FR series that is 16mm tall, but this might be a bit big and there is no room to lay it down.

Can you recommend a capacitor that is about 12mm or smaller in height?

[c_hegge]

Re: Router Recap

FR series is not optimized for size, FM series is often a bit smaller in height.

I think you're getting it backwards. FR is generally smaller in size than FM.

As for a 1000uF in 12mm height, I couldn't find anything suitable on element14. You may be able to get an 8x20mm FR, and I think it should just be able to lay down at an angle and squeeze in between the two coils.

[mariushm]

Re: Router Recap

Based on the picture on the board, the 1000uF capacitor is right by the power jack so it's more or less used as bulk storage of energy and to smooth out the dc voltage coming from the power adapter.

So the ESR is not very important, it just has to be relatively low.. you can see after the capacitor the inductors for the two dc-dc converters which further generate lower voltages.

Now look at the power adapter and see what voltage it's rated for, and what's the voltage without the adapter plugged in.
A lot of those cheap adapters have a voltage on them but at low loads, the voltage is much higher. For example, a 7.5v DC adapter may be 9-11v unplugged or at low currents.

The point is ... if the power adapter is 5v and it goes to 6-8v without any load, you should be fine if you replace that capacitor with one rated for 10v which should be a bit smaller. A high quality like Panasonic FM or FR should handle the variations in input voltage just fine.

Also, since it's just a bulk storage capacitor, you're probably going to be fine with just 820uF of capacitance there. So you have options.

[benrp]

Re: Router Recap

The power adapter has 12v 0.5A written on it, if that helps.

[mariushm]

Re: Router Recap

In that case, you have to use a 16v rated capacitor there. But you should be able to go down to 820uF without any problems.

Interesting, usually routers use 7.5-9v DC.

[benrp]

Re: Router Recap

Would I be OK to use a 25v 220uf instead of 16v 220uf

and 16v 470uf instead of 10v 470uf capacitors. (They are the closest FR ones I can get cheaply).

[c_hegge]

Re: Router Recap

^
Yes, those would be fine. The voltage rating is simply the maximum the cap can handle.

[kc8adu]

Re: Router Recap

yes if it still fits in the spot.
25v will be bigger.

[benrp]

Re: Router Recap

Finished recapping the router. I forget to mention it's a Huawei HG523a router.

I had to use a mixture of FR and FM series caps in the end, and slightly lean the 1000uf as recommended.

The 25v 220uf is a little too wide, as there is a little resistor close by I had to solder the cap raised from the pcb, so I will probably replace this with a 16v 220uf at a later date.

[Radio Fox]

Re: Router Recap

...Interesting, usually routers use 7.5-9v DC.

My 2 Netgear routers (DG834GT & DG834v4) both use 12v, and my Thomson TG585v7 uses 22v.

[ant3202]

Re: Router Recap

Finished recapping the router. I forget to mention it's a Huawei HG523a router.

I had to use a mixture of FR and FM series caps in the end, and slightly lean the 1000uf as recommended.

The 25v 220uf is a little too wide, as there is a little resistor close by I had to solder the cap raised from the pcb, so I will probably replace this with a 16v 220uf at a later date.

nice......