Ever wondered what lies beneath the sleek exterior of the high-tech Rigol DM858 multimeter? In a recent teardown video, we took a deep dive into the inner workings of this precision instrument, uncovering the components that make it tick. Right off the bat, the teardown revealed the beautiful construction and assembly quality, with key areas like power supplies, connectivity, and a clever system-on-module design.
The power supply section was straightforward, with a USB-C input and a series of switchers to step down the voltage to the required levels. The real star of the show was the SODIMM module, housing an Allwinner A40i-H quad-core Cortex-A7 processor, RAM chips, flash memory, and a power management circuit.
This modular design offers several advantages, including cost savings, flexibility, and the ability to swap out components as needed. Moving on to the input section, we encountered a curious square PCB module housing the user-accessible fuse and input protection components like gas discharge tubes, Metal Oxide Varistors, and clamping devices.
Underneath a small shield, we found relays likely responsible for input switching and range selection. One of the most intriguing discoveries was the potential use of the microcontroller’s built-in ADC (Analog-to-Digital Converter) instead of a dedicated ADC chip. This design choice, if true, would be a clever solution for high sampling rates and accurate measurements.
However, not all mysteries were solved. We encountered a few unidentified components, leaving us scratching our heads. Can you help shed light on these enigmatic parts? Leave a comment below and join the discussion!