EBME Forums Forums Maintenance Technical Assistance Codemaster - Crackling/Leaking Capacitor

I suspect he's the reason why we've had to keep them going for so long Tony I did forget to mention, of course, that we've had to provide significant input (and spares), on PMs, to keep them operating reliably.

At least spares and support (sic) are still available after all this time, which is more than can be said of many other monophasic defibrillators of their generation supplied by other manufacturers, eh?

We're just gearing up to commission about 50 Philips MRx Biphasic AED and 50 Philips FR2 Biphasic AED model "first-responder" defibrillators on our site, so sadly I will have to wave goodbye to the LP9.

As an aside: Years ago I once got asked by a manager at interview, in a hospital at Preston, what the voltage was on an energy storage capacitor in a LP9 when the output energy was charged up to 360J. I responded by telling him that it was difficult to give a figure with any accuracy because:

1) There are losses in the waveshaping components R & L thus the energy required in the capacitor to deliver 360J would be greater than expected on the face of it hence this would mean the capacitor terminal voltage would differ from the nominal voltage that's expected with an output of 360J, even if the nominal capacitance value is known.

2) Since the capacitance value of each capacitor is subject to wide tolerances only an estimate of voltage in the range X to Y KVolts can be given (also considering 1 above). I gave a "ballpark figure" but he wanted to know exactly (I guess this person must have had the P.D. on a LP9 unit in the workshop measured at 360J or something).

I indicated I knew the nominal capacitance value in the LP9 (as I'd had to change one or two) and gave the "ballbark figure" for the P.D. across capacitor, charged to around 360J, but he wasn't pleased with my answers I could tell. He then came out with an exact figure that I should have known, apparently. Needless to say I didn't get the job.

So much for the stuff I learned at "O" and ONC level - Talk about a "closed question", eh?

We have two new Codemaster capicitors in our stores and have just completed a replacement programme for them. So if anyone wants to make us an offer...

Andy

Hi Everyone,

Font, i agree with your comments so have informed my manager and am awaiting further notice. We have been informed that if the device passes all tests then it is ok to go back into service. But also from the same source that it is preferred the codemasters are replaced with newer models. We are in the process of identifying all capacitors exhibiting this popping noise.
As R. Ling says, once you get breakdown of electrolyte, then loss of capacitance, more leakage, further breakdown etc. This accelerates the failure of the capacitor.

Font, as your HV caps are showing visual signs of electrolyte leakage i would assume it is at a further stage of failure and might have failed the calibration anyway in which case RFS would be the solution.
Ill keep you informed on our position here when i know anything.

Hi all, Nice to see some responses on this one. I have some good and bad news for you.

Good news - I found the OEM capacitor supplier in the UK and ordered and received some replacements yesterday- at about a third of the cost Philips charged when they were available!!

They are identical and were manufactured specifically for the Codemaster - comes complete with bleed resistor and cables.

Bad news - There are only 3 left in the world - I can provide the supplier name and a contact if its OK to post the address etc on the site.

Go ahead

So that's the challenge - I bet there are more than three somewhere out there in the world!

Meanwhile, can the faulty capacitors be repaired, I wonder? Would it be a cost-effective option (how about it, Richard)? Is it worth stripping out the capacitors from otherwise faulty defibs., and defibs. being scrapped?

Here it is!

Contact: Dilesh, he was very helpfull, just quote he original catalog number on the capacitor - he will now be familiar with it since we just made a purchase.

I am sure that they may be able to supply other capacitors originally manufactured by Maxwell -now General Atomics.
I have provided a link below.

They sent us a credit rating - bank details form for Finance to complete as first customers otherwise its pro-forma and cheque with order.

AMS Technologies Ltd.
Unit 11, St. John's Business Park
Lutterworth
Leicestershire, UK
LE17 4HB
Tel: +44 (0)1455 556360
Fax: +44 (0)1455 552974

www.ams-technologies.com
http://www.ams-technologies.com/gb/en/products/detail/id/1109/cat/190/