From: me@privacy.net   
      
   Tzortzakakis Dimitrios    
   news:oddbmg$nt2$1@dont-email.me Fri, 21 Apr 2017 16:26:51 GMT in   
   alt.engineering.electrical, wrote:   
      
   > On 21/4/2017 1:56 μμ, Diesel wrote:   
   >> Tzortzakakis Dimitrios    
   >> news:oc88v5$8p2$1@dont-email.me Fri, 07 Apr 2017 14:53:06 GMT in   
   >> alt.engineering.electrical, wrote:   
   >>   
   >>> A client left a faulty microwave oven at my friend's shop, I   
   >>> opened it up and first thing I checked was, of course the HV   
   >>> fuse. It was open so a new one. Nothing. Checked with my HV   
   >>> probe, at the transformator secondary 3.5 kV(AC). At the   
   >>> magnetron nothing, no DC at all. Thought it was the HV capacitor   
   >>> or the HV diode.Took them home, measured the capacitor with my   
   >>> capacitance meter, 1 μF ok. Checked with my insulation tester   
   >>> that can put up to 1000 volts, the diode, forward bias 0 Ω,   
   >>> reverse bias >10 ΜΩ ok.Of course I didn't do anything as when   
   >>> you repair household appliances you must be absolutely sure   
   >>> you'll repair it, there's no room for experiments.Anyone with a   
   >>> brainwave? Again, the trafo AC ok, DC nothing-something wrong   
   >>> with the magnetron?   
   >>   
   >> What is the make/model of the meter you've mated the HV probe   
   >> with to test the voltage coming off the transformer?   
   >>   
   >>   
   > It's the Benning MM-1. A very good one, I think. I think I   
   > followed the correct procedure or I wouldn't be here talking to   
   > you:-) The HV probe's division factor is 1000, that means that 3.5   
   > kV will appear in the multimeter as 3.5 volts. The probe's manual   
   > says never to choose auto range, and make sure that the input   
   > impendance of the multimeter must be at least 10 MΩ. If the input   
   > impendance is 1 MΩ, then it's 2000.That means 1 kV becomes 0.5   
   > volts. I don't know the input impendance of my multimeter, I did a   
   > google search obviously which turned out nothing. I have tested   
   > the HV probe measuring line voltage 0.22 kV ok.   
   >   
      
   Thanks! Which HV probe are you using? I forgot to ask previously. :)   
      
   I've been thinking about the Fluke 80K-40. I just need to see if the   
   DMMs I've presently got are satisfactory for it. I've been wanting to   
   test HV transformers (neon sign, microwave, etc)...   
      
      
      
   --   
   I would like to apologize for not having offended you yet.   
   Please be patient. I will get to you shortly.   
      
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