[Lowfer] Wild Bill's Loop Lessen #51

[Bill Ashlock]

Mike S,

>the LW-MAX's final was drawing more current than expected: 250mils >@11.5V

2.87 watts. Yikes! The output transistors must be smokin! Tis a good thing 
you are reading approximately .83A on the loop, which is equal to the 
current that you read when you substitute the 1.3 ohm test coil. This says 
that loop AC resistance is also 1.3 ohms and the signal you have been 
sending represents a .95W output from the LW-max. The problem is with the 
efficiency of the output stage of the LW-max - about 35%! A scope you would 
likely show you the filter is the cause of the problem.

BTW: Be darn sure that the Vcc current you are reading on the final is for 
the output transistors alone and not for any other active component.

Bill


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