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Switching Power Supply

Discussion in 'General Technical Questions and Answers' started by K7OFG, Nov 20, 2021.

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  1. K7OFG

    K7OFG Ham Member QRZ Page

    I've had to start using a switching power supply in my shack and am wondering if I should leave it on 24/7 like I did my old Linear PS or turn it off after use? I was told that the old PS should be left on and so I did unless I was to be away from my home QTH for any length of time.
    Thanks for any suggestions.
  2. WA7ARK

    WA7ARK Ham Member QRZ Page

    In my 60+ years electronics experience, I have have seen several power supplies fail. Most failed at initial turn-on after a cold start (except for those that failed when I accidentally shorted them :().

    Based on my small sample, switchers are more likely to fail at turn-on than linears. Switchers fail much more spectacularly than linears.
    Last edited: Nov 20, 2021
    AC0OB likes this.
  3. WA9FZB

    WA9FZB XML Subscriber QRZ Page

    I probably should not speak of this, but I have been using the same Samlex SEC-1223 on four rigs (one after another) for about 15-18 years. I do not leave it on when it is not in use. I have the old fashioned "big switch" that removes power from my radio table when I am not using it, so the power supply is switched on and off at each operating or listening session. No problems, so far. . .

    (Hope it isn't reading over my shoulder.)
  4. K4JDH

    K4JDH Ham Member QRZ Page

    I ran an Alinco for 10 years 24/7. Other than cleaning, it was fine. I retired it to backup duty and replaced it with an identical unit.
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I don't use SMPS devices for my home ham station, although it's impossible to eliminate them from tons of other stuff we have 'round the house.

    But at least most SMPS designs dissipate very little power in standby and of course are more efficient under load as well, compared with linear designs -- so leaving one turned on all the time probably adds almost nothing to the electric bill, even over the course of a year.

    There's no "off" switch on laptop computer power modules and myriad SMPS units we all have and I leave them all plugged in all the time, so they're always running.
  6. KG6BRG

    KG6BRG Ham Member QRZ Page

    I have the same Samlex SEC-1223 supply, I bought it new in 2000. It's still just as reliable as it was 21 years ago. I switch it on about 5 AM on average, and turn it off about 9 PM. No problems with it at all.
  7. K7OFG

    K7OFG Ham Member QRZ Page

    Thanks for the come back and as usual there is a lot of differing opinions. Mike, WA7ARK , made a lot of sense as I do see a voltage spike as I turn it on. I'll run a test and leave it on as I used to with the linear.
    Thanks to all.
  8. K8JD

    K8JD Ham Member QRZ Page

    I know the switching supplies have many more componants and a more complex circuitry than the old analog ones . Seems like a more likely possibility for failure.
    Do you give up reliability for lighter wieight?
    My Astron RS35 analog supply has been riunning my radios for nearly 30 years now, on 24/7 just in case.
  9. N8VIL

    N8VIL Premium Subscriber QRZ Page

    I like to shut most things off now when they are not in use. I came home a couple times to "What is that smell?" Things usually fail when your not home. My wife now has a paranoia when I leave things powered on unnecessarily.
    One item was a Samlex SEC-1223 switch mode power supply. The 3 output filtering caps burst. It was and easy fix. I replaced the caps and is still going strong.
    Last edited: Nov 22, 2021
  10. KV6O

    KV6O Ham Member QRZ Page

    Lighter weight, lower cost, higher energy efficiency.

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