XPost: sci.electronics.equipment   
   From: CFKinsey@military.org.jp   
      
   On Fri, 17 Jul 2020 15:02:16 +0100, Rich  wrote:   
      
   > In sci.electronics.equipment Commander Kinsey    
   wrote:   
   >> On Fri, 03 Jul 2020 02:20:53 +0100, RheillyPhoull    
   wrote:   
   >>   
   >>> On 2/07/2020 10:41 pm, Ralph Mowery wrote:   
   >>>> For a real scare you should see some of the safety movies that   
   >>>> Fluke put out.  They show under test conditions what can hapen to   
   >>>> inexpensive meters and their meters under different conditions like   
   >>>> having the meter set for amps and putting across a 480 volt circuit   
   >>>> that has plenty of amps .   
   >>>>   
   >>> Ahh the old "Leaving it on amps" trick.  How many of us can say they   
   >>> never did it ?   
   >>   
   >> I find it crazy that you can select volts and have the wires in the   
   >> amps holes.  The switch should change the contacts.  I've broken a   
   >> meter doing that, just measuring the voltage on a car battery.  £100   
   >> meter, but UNFUSED FFS!  At least the mA range was fused, but they   
   >> couldn't be bothered putting in a 20A fuse for the big range....   
   >   
   > The separate amps jacks exist for at least two reasons:   
   >   
   > 1) If the range switch also switched in/out the current shunt, then the   
   > user could accidentally create a short circult across the probe tips   
   > simply by turning the range switch to or across the amps measurement   
   > ranges.  Even if they were quickly turning /across/ the amps settings   
   > ranges, a brief short circuit would be created, which would cause   
   > damage to the meter as well as the device under test depending upon   
   > what was connected at the time.   
      
   Then you put the amps ranges on one end of the dial.  You would never go   
   through them.  And what idiot turns the dial while it's connected?!   
      
   > 2) By having the amps jacks separate, the range switch itself does not   
   > have to have contacts beefy enough to carry the current for the amps   
   > settings.  Remember, when measuring amps, the current being measured   
   > flows *through* the meter itself.  This would require very different   
   > (and likely much more expensive) range switch contacts.   
      
   Or a relay.   
      
   > Some meters do have sensors for the amps jacks that sound an alarm if   
   > the probes are inserted in the amps jacks but the range switch is on a   
   > different setting than amperes.   
      
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