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Old 14th Aug 2019, 8:10 pm   #5
ms660
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Join Date: Apr 2011
Location: Cornwall, UK.
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Default Re: Avo 7 meter - no voltage reading

Quote:
Originally Posted by David G4EBT View Post
Worse still if we apply an AVO 7 (or any 1,000 OPV meter) on the 10 Volt range across the junction as it will be like putting a 10K resistor across the 100K one, so the reading will be 1 Volt
It's worse, the AVO 7 is a 500 OPV job not a 1,000 OPV one, the total resistance across the input terminals when the divide by two function is selected is the same as it is when the divide by two function is not selected.

If you look at the schematic in the manual and select a range you can add up all the resistances, for instance take the 10 volt range.....4,500 + 450 + 50 which equals 5,000 Ohms which equals 500 OPV (5,000/10)

Lawrence.

Last edited by ms660; 14th Aug 2019 at 8:27 pm. Reason: Explanation example
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