EEVblog 1448 – Convert a Fluke 77 IV to True RMS for 10 CENTS!

How to convert a Fluke 77 IV average responding multimeter into a True RMS model 177 for 10 cents.
*Plus calibration gear

Should also work for converting a Fluke 83V to 87V True RMS measurement vs Average Responding And how to calibrate a Fluke multimeter.
Fluke 87V service manual with schematic: https://xdevs.com/doc/Fluke/87V/Fluke_87V_Full_service_manual_with_schematic_and_electrical_parts_list_Service_Manual-87VANFullService.pdf

00:00 – Hacking a Fluke 77 IV Multimeter
00:35 – Is the Fluke 70 series discontinued?
01:15 – Fluke History
03:10 – I noticed something…
04:49 – The AD737 True RMS converter chip
06:04 – Theory of Operation
07:21 – What is Crest factor
08:58 – How do they do it?
09:25 – Fluke 87V Schematic and the custom ASIC
10:53 – Let’s modify it!
12:58 – A sine wave is NOT a crest factor of 1
14:01 – Soldering
15:15 – Will it work?
16:46 – Calibration procedure
20:09 – Winner Winner Chicken Dinner

Forum: https://www.eevblog.com/forum/blog/eevblog-1448-convert-a-fluke-77-iv-to-true-rms-for-10-cents/

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