Did my power supply fail or just wear out?

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A real power supply failure is a uncommon prevalence supplied the next happens:

  1. The producer has taken the suitable steps on element analysis, element derating and has utilized sound design strategies.
  2. The consumer is working the product in accordance with the producer’s directions.

TDK-Lambda, for instance, places many parts by way of a myriad of stress checks together with voltage testing beneath excessive humidity and atmospheric pressures, past the producer’s specified most rankings.  Solely upon passing these checks is the element provider added to the accredited vendor’s record.

Monitoring primary switching currents at high line and high ambient temperatures throughout transient loading can reveal how a lot design margin the power supply has.  Beneath you may see that our competitor’s power transformer is inadequately sized and is drawing an enormous enhance in present because it saturates.

So, after I hear “My power supply failed after just three years within the area” from potential prospects, I review their application and infrequently should ship the dangerous news.  Their power supply has just worn out.

Just lately a producer of semiconductor fabrication tools referred to as me.  They had been utilizing a one-year guarantee power supply and had been operating it on the full rated power stage. 

I requested the Engineer how lengthy was their tools sometimes operated within the area.  “Our tools is often operating 24/7 (24 hours a day, 7 days every week)” was the reply and “our prospects anticipate to make use of the machine for at the very least ten years.”

In a power supply, essentially the most frequent wear-out element is the electrolytic capacitors.  Capacitor life has improved significantly with fairly priced electrolytics, now sometimes rated for 10,000 hours at 105°C.  Even then, that's solely 1.14 years when used 24 hours a day in a really harsh setting.

The answer is sort of easy, select an acceptable grade of power supply and apply enough deratings.  I at all times ask concerning the application, the anticipated area life, the fee influence of their buyer’s tools being out of service, and the fee influence of getting to service the tools.  If the application is in a distant application or would require a service particular person to drive or fly out to the situation, paying an additional $50 or even $100 extra for an rugged, industrial grade power supply will likely be extra economical than paying for a $500 area service name, maybe 3 years instances.

I typically equate power supply life to that of shopping for an inexpensive set of brake pads for one’s automotive.  Sure, it prices much less initially, however you'll most likely be again for one more set of pads (and spending time within the restore store) in lower than half the time larger high quality set of pads would final.