Identify the part - what is it?

[p314]

 

[Nigel Goodwin]

At a guess I would say it's probably a 'super capacitor', particularly based on it's low voltage rating.

 

[DerStrom8]

5.5V 47nF capacitor, I would guess.

 

[tronitech]

NG is most likely correct.

Data sheet **broken link removed** somewhere.

 

[Nigel Goodwin]

5.5V 47nF capacitor, I would guess.

I suspect the 473 means a MUCH higher value than that

 

[DerStrom8]

I suspect the 473 means a MUCH higher value than that

I don't think so. That's a standard code, the code is for picofarads. 47 000 pF = 47nF (Nigel, I know you're familiar with the code, I'm saying this for the benefit of the OP). I don't think the code on this device is different.

 

[JimB]

That's a standard code, the code is for picofarads. 47 000 pF = 47nF

I agree, but, that is a very large package for a 47nF capacitor.
And the 5.5v rating? a bit low and precise for the average capacitor.
And polarised? a 47nF polarised capacitor? a new one on me.

A "super cap" sounds more likely.

JimB

 

[DerStrom8]

I agree, but, that is a very large package for a 47nF capacitor.
And the 5.5v rating? a bit low and precise for the average capacitor.
And polarised? a 47nF polarised capacitor? a new one on me.

A "super cap" sounds more likely.

JimB

I understand where you both are coming from, but it also looks quite old. Capacitor technology has changed quite a bit. I'd like the OP to get his hands on a capacitor meter and measure it. I think we can all agree it's definitely a cap. If it's 47nF it'll show up on the meter. If it's a super cap, it most likely won't (value is too high).

 

[Ian Rogers]

Why are you still debating... tronitech has given the datasheet FMCOH473ZF 0.047(F)...

 

[Nigel Goodwin]

I don't think so. That's a standard code, the code is for picofarads. 47 000 pF = 47nF (Nigel, I know you're familiar with the code, I'm saying this for the benefit of the OP). I don't think the code on this device is different.

It's only a 'standard' if everyone sticks to it, in this case at 5.5V and a large capacitor it's obviously NOT only 47nF - and Ian has bothered to look at the PDF to get the correct value

The 5.5V rating means it's obviously a 'super capacitor' and will have a very large value, hence the different meaning of the numbers.

 

[spec]

It's 5.5V, 47mF (47,000 uF)

The bottom number is the date code
The left number is the voltage
The right number, 473, is in uF rather than the conventional pF. As normal, the first two digits are significant and the third number signifies the multiplier. ie 47uf * 1000 = 47mF (47,000uF).

spec

 

[dr pepper]

I have a few, I put them in my piezo buzzers drawer!, the markings are the same.

The only thing I have that will measure large caps is my superprobe, it says its 10,000 uF, but then its not meant to measure supercaps.
I wonder if the markings mean 47,000uF.

 

[spec]

You can get a good idea of a large capacitor value by eye, with a voltmeter, watch, 3V coin cell, and a resistor. To check a 47,000uF capacitor. Connect the battery to the coin cell via a 5.1K resistor and note how long the voltage on the capacitor takes to rise from 0V to 1V. If it is 10 seconds the capacitor value is 4.7mF (47,000uF).

spec

 

[vtech]

As an addition to what has been discussed,

Kemet was also licensed to manufacture the exact same part.
The shelf life of super capacitors are rather limited and when it comes to NEC, the production date code even more dubious.
Since NEC has gone through so many changes, I do not believe they even know it and good luck finding that.

As an Example, if you were to follow their old numbering system, you can see the accuracy of date code "M"


In my experience, the majority of super caps pulled from PCB's are either dead or about to. In my days with Consumer Electronics, I used to see it very often across the product lines.
An Go-No-Go test is to utilize an adjustable power supply. While it is not exact, it is a good indicative.

Set it to zero and hook it up (watch polarity) and while monitoring the voltage, slowly advance it to cap's voltage rating (5.5 V in this case)---no more.
Allow it to sit about a minute and turn the power supply back to zero. (If using supply w/ analog meters, at this point you can turn the supply off)
A good cap will retain the charge and your supply is now a voltmeter as it will show the decaying charge.
Depending on the capacitance value and condition, the decay time varies.

As a rule of thumb, if the charge is held more than 30~45 seconds, it is probably a good cap.

 

[schmitt trigger]

Identify the part - what is it?
Are we talking about the black box or the coin?

 

[Nigel Goodwin]

In my experience, the majority of super caps pulled from PCB's are either dead or about to.

All my experience of 'super caps' (a stupid name! ) is replacing faulty ones, they are really exceptionally unreliable - I certainly wouldn't ever think of removing one from a PCB to reuse (or indeed ever think of using one in the first place ).

 

[p314]

Thank you, fellas, your comments and the datasheet from tronitech were very helpful. I suspected it to be some variety of a capacitor and before posting here I tried it with an LCR meter of this type: **broken link removed**
- strangely the part was identified as two diodes in series!
Now I tried the method from the datasheet (chapter8) and indeed it is in the region of tens of mF. The following variation of method described by spec above also works well for estimating the value:
Using a bench power supply - set mode to constant current, max voltage to 5V, and current to e.g. 2mA and start charging the cap with constant current of 2mA. Time the charging until the voltage gets to e.g. 3V. In my case it was 33 sec.
Final capacitor charge Q = V x C = I x T . Hence C (Farad) = I (Amp) x T (sec ) / V (volt) = 0.002A x 33s / 3V = 0.022F which is not too far from the declared 47mF, given inacuracies of the measurement method.

Thanks again - it was educational!

 

[dr pepper]

Turns out I have a few of them,

 

[DerStrom8]

Turns out I have a few of them,

View attachment 101761

 

[vtech]

All my experience of 'super caps' (a stupid name! ) is replacing faulty ones, they are really exceptionally unreliable - I certainly wouldn't ever think of removing one from a PCB to reuse (or indeed ever think of using one in the first place ).

Perhaps you may not be aware but on this side of the pond the term "Super" is often used to denote "big quantity" which may not make a whole lot of sense to our friends in UK ( hey, I have British relatives)----but sorry I did not start the term

... they are really exceptionally unreliable-

I'd have to disagree with that sentence;
Granted it may be unreliable in Consumer Electronics which is mostly based on design issue and not critical. (Although countless number of them were used throughout the product cycle).
When designed properly, lifetime hours are not that far from the respective datasheets. There are many factors involved with several reports by likes of Yamaha, Panasonic ELNA and Mitsumi
Speaking of reliability, in Aviation, Airbus 380 has been using super capacitors for some time (Emergency evacuation sliders). Wonder how reliable is that