Originally Posted by Power Factor
I can hear Colm talking about electrolytics now... :-)
Really? You must be prescient. :-)
I like it when you actually post something that can be discussed in this thread. You could be a real help in understanding series mode technology.
Surely you don't believe that electrolytic capacitors do not degrade over time. If so, can you comment on this
Your choice of a passive LC speaker crossover is a good example of what happens with electrolytics. A two-way or three-way crossover might be a better example than a subwoofer crossover, though. The electrolytics in them do degrade over time, usually decades. The parameters can change enough over time that they affect the sound or just fail. I have resurrected numerous old crossovers, TVs, aircraft avionics, etc. where the only failed part was one or more electrolytic capacitors. The electrolytics in the avionics didn't last nearly as long as the ones in the speakers because of the harsher conditions they were exposed to (aircraft parked on a ramp year round).
As I said previously, the fact that electrolytics degrade over time is not a significant issue. I agree with you that properly selected and applied, electrolytic capacitors will have a long service life. Your company can afford to warrant your equipment for 10 years because of that. Properly selected and applied MOVs can have a long service life, too. That is why at least some manufacturers of MOV based devices can afford to warrant at least some of their devices for 10 years. Neither technology, however, will last forever.
I am curious, however, about what happens as the electrolytic capacitors in series mode devices age. My guess is that the electrolytics are chosen so that they have a high probability of adequately handling those 6000V, 3000A surges for at least 10 years. Care to explain it to a layman? Does the let through voltage increase? Why or why not? Does the size of the surge that can be handled decrease? Why or why not?
I assume that series mode technology does what you claim it does, that is it provides a lower let through voltage (zero of close to zero excursion from nominal in the latest versions) and doesn't create a surge on the equipment grounding conductor. My only question is why should I care if less expensive MOV based devices, properly selected and applied, will give me adequate protection. Based on what I have read by Martzloff, as mentioned above, they will. Is he wrong? Did I misunderstand him? If so, please explain.
As I stated long ago, I don't doubt that there are applications where series mode is the way to go. I would really like to know what were the driving factors for engineering savy customers to select SurgeX products for particular applications. I can imagine one might be that in mission critical applications that SurgeX might be chosen over other devices simply because the cost of a failure might be so great that even a small improvement in reliability would be worth the cost. Care to give us any others?
It is informative to hear what you have to say about the difference between Furman and SurgeX. You certainly need to protect your trademarks. You don't want them to wind up like corn flakes or refrigerator. It did seem to me that the series section of the Furman product was less robust than the SurgeX product. And the necessity of the MOVs did seem questionable with a series device. Care to elaborate?
Why not answer some questions and educate us? We are really not out to get you. Well, at least I am not... Who knows, you might get some customers out of it.