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Re: [hp_agilent_equipment] Re: HP power supplies

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  • Peter Gottlieb
    Heck, you can get some of those to go unstable or trip their main breaker if you simply try to move the voltage control up and down rapidly. About the diode,
    Message 1 of 19 , Sep 10, 2010
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      Heck, you can get some of those to go unstable or trip their main
      breaker if you simply try to move the voltage control up and down rapidly.

      About the diode, yes, definitely. I have on occasion put the sense lead
      after it. I also put a large diode across the output, just in case...

      Peter


      On 9/10/2010 10:37 PM, J. Forster wrote:
      >
      > Agreed. The older Harrisons were pretty bad. Some of the later HP supplies
      > with the ivory paint were pretty good.
      >
      > My preference has always been for Lambda and Kepco, although I recently
      > got a Power Ten switcher which is quite impressive, IMO.
      >
      > You really do need reverse protection diodes with most any supplies if
      > your load stores significant energy.
      >
      > FWIW,
      >
      > -John
      >
      > ============
      >
      > > HP and power supplies has not been a great relationship. The
      > > old HP/Harrison supplies are mostly junk. They burn out with
      > > very little effort. For instance, hook the output up to a large
      > > capacitor, and turn the power off. Or hook the output up to a
      > > large capacitor, and turn the voltage up and down 5 or 6 times
      > > quickly.... poof! Don't even think of using one to charge a
      > > battery. If you do, and the power fails, your supply will
      > > go up in smoke.
      > >
      > > Although I have several HP supplies, I much prefer just about
      > > any other manufacturer.
      > >
      > > -Chuck Harris
      > >
      > >
      > >
      > > David I. Emery wrote:
      > >> On Fri, Sep 10, 2010 at 12:10:35PM -0500, Peter Gottlieb wrote:
      > >>
      > >>> Whatever. The power supply trips it after a minute or so and the true
      > >>> RMS fluke clamp on says 25 amps. A toasty 12 AWG power cable is a
      > >>> sanity check on that.
      > >>
      > >> First and obvious question is why do you not beleive the power
      > >> supply is broken ? ... that level of (in)efficiency doesn't make a lot
      > >> of sense... maybe some product somewhere is that bad but HP stuff
      > >> usually
      > >> isn't...
      > >>
      > >>
      > >>
      > >
      > >
      > > ------------------------------------
      > >
      > > Yahoo! Groups Links
      > >
      > >
      > >
      > >
      >
      >
    • Peter Gottlieb
      I believe it is not broken because I have seen others of the same type behave in the same way, and that other than its quirks it operates fine. Their new
      Message 2 of 19 , Sep 10, 2010
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        I believe it is not broken because I have seen others of the same type
        behave in the same way, and that other than its quirks it operates fine.

        Their new supplies are much better, although some of them are relabeled
        TDK/Lambda units.


        On 9/10/2010 5:47 PM, David I. Emery wrote:
        >
        > On Fri, Sep 10, 2010 at 12:10:35PM -0500, Peter Gottlieb wrote:
        >
        > > Whatever. The power supply trips it after a minute or so and the true
        > > RMS fluke clamp on says 25 amps. A toasty 12 AWG power cable is a
        > > sanity check on that.
        >
        > First and obvious question is why do you not beleive the power
        > supply is broken ? ... that level of (in)efficiency doesn't make a lot
        > of sense... maybe some product somewhere is that bad but HP stuff usually
        > isn't...
        >
        > --
        > Dave Emery N1PRE/AE, die@...
        > <mailto:die%40dieconsulting.com> DIE Consulting, Weston, Mass 02493
        > "An empty zombie mind with a forlorn barely readable weatherbeaten
        > 'For Rent' sign still vainly flapping outside on the weed encrusted
        > pole - in
        > celebration of what could have been, but wasn't and is not to be now
        > either."
        >
        >
      • J. Forster
        I m not so sure about the wisdom of putting the sense lead on the load side of the isolation diode. The rationale is obvious, but it seems possible that if the
        Message 3 of 19 , Sep 10, 2010
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          I'm not so sure about the wisdom of putting the sense lead on the load
          side of the isolation diode. The rationale is obvious, but it seems
          possible that if the PS were switched off with a capacitor or battery
          load, the sense circuitry could get fried.

          I'd be inclined to use two diodes, one in the power lead and one in the
          sense lead in a wired OR. This is definitely a "read the manual" question,
          IMO.

          John

          =============


          > Heck, you can get some of those to go unstable or trip their main
          > breaker if you simply try to move the voltage control up and down rapidly.
          >
          > About the diode, yes, definitely. I have on occasion put the sense lead
          > after it. I also put a large diode across the output, just in case...
          >
          > Peter
        • Peter Gottlieb
          Perhaps, who knows. There are a lot of power supplies around if you know where to look and ask around so I ve been cavalier with them and can be rough because
          Message 4 of 19 , Sep 10, 2010
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            Perhaps, who knows. There are a lot of power supplies around if you
            know where to look and ask around so I've been cavalier with them and
            can be rough because if one fails I either make a quick fix or replace
            it. And the strange thing is, despite that attitude, I haven't had a
            failure since I can't remember when. And yeah, I charge batteries, run
            motors, even draw arcs with carbon rods to make thermocouples.

            That said, when I am going to leave batteries on charge unattended, I
            use a diode and fuse to feed the batteries and a reverse protection
            diode just for fun. The batteries I charge are capable of thousands of
            amps of fault current and I really don't want to burn my place down.


            On 9/10/2010 11:57 PM, J. Forster wrote:
            >
            > I'm not so sure about the wisdom of putting the sense lead on the load
            > side of the isolation diode. The rationale is obvious, but it seems
            > possible that if the PS were switched off with a capacitor or battery
            > load, the sense circuitry could get fried.
            >
            > I'd be inclined to use two diodes, one in the power lead and one in the
            > sense lead in a wired OR. This is definitely a "read the manual" question,
            > IMO.
            >
            > John
            >
            > =============
            >
            > > Heck, you can get some of those to go unstable or trip their main
            > > breaker if you simply try to move the voltage control up and down
            > rapidly.
            > >
            > > About the diode, yes, definitely. I have on occasion put the sense lead
            > > after it. I also put a large diode across the output, just in case...
            > >
            > > Peter
            >
            >
          • arthurok
            hp really didnt design them as batery chargers ... From: J. Forster To: hp_agilent_equipment@yahoogroups.com Sent: Friday, September 10, 2010 10:57 PM
            Message 5 of 19 , Sep 10, 2010
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              hp really didnt design them as batery chargers
              ----- Original Message -----
              From: J. Forster
              To: hp_agilent_equipment@yahoogroups.com
              Sent: Friday, September 10, 2010 10:57 PM
              Subject: Re: [hp_agilent_equipment] Re: HP power supplies



              I'm not so sure about the wisdom of putting the sense lead on the load
              side of the isolation diode. The rationale is obvious, but it seems
              possible that if the PS were switched off with a capacitor or battery
              load, the sense circuitry could get fried.

              I'd be inclined to use two diodes, one in the power lead and one in the
              sense lead in a wired OR. This is definitely a "read the manual" question,
              IMO.

              John

              =============

              > Heck, you can get some of those to go unstable or trip their main
              > breaker if you simply try to move the voltage control up and down rapidly.
              >
              > About the diode, yes, definitely. I have on occasion put the sense lead
              > after it. I also put a large diode across the output, just in case...
              >
              > Peter





              [Non-text portions of this message have been removed]
            • Poul-Henning
              I managed to lay my hands on a HP6626A and love it. Advantages: 4 separate outputs, can be put in series or parallel Very precise Very quiet Disadvantages: No
              Message 6 of 19 , Sep 11, 2010
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                I managed to lay my hands on a HP6626A and love it.

                Advantages:

                4 separate outputs, can be put in series or parallel

                Very precise

                Very quiet

                Disadvantages:

                No knobs to twirl

                Connections on the backside.

                Highly recommended.

                Poul-Henning
              • Chuck Harris
                As far as I can tell, based on my own herd of HP supplies, they designed them to be shelf queens. I have trouble being really impressed with a supply that can
                Message 7 of 19 , Sep 11, 2010
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                  As far as I can tell, based on my own herd of HP supplies, they
                  designed them to be shelf queens.

                  I have trouble being really impressed with a supply that can be
                  burned out by simply cranking its voltage control from one extreme
                  to the other a couple of times quickly.... no load.

                  Also, if you go through the manual, they show all sorts of sample
                  uses that involve the supplies in series and parallel. If you
                  actually try to use the supplies in that way, poof!

                  The failures of the HP/Harrison supplies are always the same, the
                  driver transistors pop.

                  -Chuck Harris

                  arthurok wrote:
                  > hp really didnt design them as batery chargers
                  > ----- Original Message -----
                  > From: J. Forster
                  > To: hp_agilent_equipment@yahoogroups.com
                  > Sent: Friday, September 10, 2010 10:57 PM
                  > Subject: Re: [hp_agilent_equipment] Re: HP power supplies
                  >
                  >
                  >
                  > I'm not so sure about the wisdom of putting the sense lead on the load
                  > side of the isolation diode. The rationale is obvious, but it seems
                  > possible that if the PS were switched off with a capacitor or battery
                  > load, the sense circuitry could get fried.
                  >
                  > I'd be inclined to use two diodes, one in the power lead and one in the
                  > sense lead in a wired OR. This is definitely a "read the manual" question,
                  > IMO.
                  >
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