This is a continuation of the review of the U1461A Keysight Insulation Resistance Handheld meter.
In this post I take them apart down to the main PCB and give you a tour in detail, Identifying the components where possible (Where I can find them on the internet)
Be warned, this is a one hour video and the second half is a slow and detailed scan over the board (Both Sides) so please dont complain about that. You have been warned. You can easily fast forward or just skip the latter half.
In the tear down I also strip my U1272A and U1273A to the same level for a side by side comparison just for fun.
Video is Here:
The interesting thing about the U1461A is the huge transformer at the top of the board, well away from the banana sockets that is used to generate the high Voltages for the Insulation testing.
The U1461A images are here:
The U1272A here:
And the U1273A (With OLED Removed)
Components identified during the testing are linked in below for your pleasure. The HYCON HY3131 makes very intersting reading as it explains a great deal of detail as to the workings of a modern Multimeter. this chip is the heart of the ADC for most of the ranges and functions.
15N06G 15A, 60V N-CHANNEL POWER MOSFET
IXTA3N120 High Voltage Power MOSFETs
UF840L8A, 500V, 0.85Ω, N-CHANNEL POWER MOSFET
AD8436 Low Cost, Low Power, True RMS-to-DC Converter
MAX4581/82/83 Low-Voltage, CMOS Analog Multiplexers/Switches
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