From: colinmarr0@gmail.com   
      
   > On 2023-02-22, StevWolf wrote:    
   > > I have a dead Ac/Dc adaptor. I'm busted it just to learns stuff.    
   > > Im trying to learn how to test Transformers. This transformer says on    
   > > it AMS10405 RG 1320F. I provide this to give all information, however    
   > > Im not sure it matters much to my question.   
   > Can't find the part with a quick google. I'm going to assume it's not    
   > generally for sale (e.g. only sold in the Chinese market for making    
   > other stuff with; or old).   
   > >    
   > > I have so far removed from what I can gather are the Primary wires    
   > > from the board. I assume they are because they are white and black and    
   > > are literal wires going into transformer, as oppose to all the other    
   > > connections which appear to be pins in the circuit board. I believe    
   > > to properly test transformer you need to remove it fully eventually.    
   > >    
   > > Here are my results with digital tester, When set to continuity, which    
   > > appears to be (2) ohms setting. I get Beep and .002 Ohms.    
   > > This seems to be very low ohms.   
   > Might be that you're misinterpreting the meter. Mine here _always_    
   > shows the decimal point when in continuity mode. If yours is like mine    
   > in that regard, it's not supposed to be read as "2 milliohms", but    
   > rather "2 ohms" (which might be a concerningly high value, depending on    
   > how large this transformer happens to be).    
   >    
   > Quick sanity check for yourself -- grab something you know the    
   > resistance of (or can check easily), such as a 100 ohm resistor. You'll    
   > probably see it displayed in the range of " .105" to " .095" (under the    
   > assumption of a standard 5% tolerance resistor).    
   >    
   > My meter here does have some error between resistance and continuity,    
   > generally with continuity mode showing an ohm or two less than    
   > resistance mode; at least across the 10 resistors I tested with just    
   > now.    
   >    
   > HTH :)    
   >    
      
   Well thanks for your comments. You have encouraged me to dig into my meter a   
   bit.   
    Here are some results of my meter using some resistors I have.   
      
   100R set to 200  is 107 Ohms - Ok I guess   
   1 R set to Continuity says .974 Ohms - Yes seems OK.   
   .39 R set to Continuity says .002  - thats close   
   .39 set to 200 says  3.6 (which seems odd to me)   
      
   Importantly The manual for the for the meter seems to say that it will show   
   continuity for anything less than 50ohms.   
   Also while the meter has no information about the following, in the manual,   
   when I set it to Continuity there is a little 2 under the decimal point, in   
   the same way that it shows up when set to 200 for example with the respective   
   200 under the decimal. I    
   asume that means 2  Ohms,    
      
   Sooo Im still trying to figure out if this transformer primary is bad?   
   Maybe transformers which are basically two sets of winding in simple   
   transformers dont have much resistance.    
   I mean wire has loss but not a lot. ??    
   Again Im just trying to learn and understand.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)