The Culprit : Dirty external potentiometer tracks or a broken wiper signal wire.
The JYMC220BI (often referred to in manuals as JYMC-220B-II ) is a specific model of a DC motor speed control board. While direct, manufacturer-supplied schematics for this board are not publicly available online, this guide will explain its purpose, where you might encounter it, and the most effective methods to locate its full schematic for repair or analysis. jymc220bi schematic full
: Intercepts oncoming current spikes; typically utilizes a 12A to 15A fast-acting cylindrical glass or ceramic fuse. The Culprit : Dirty external potentiometer tracks or
: Caps the peak voltage output sent to A+/A- to protect the lathe from spinning past safe structural RPM limits. : Intercepts oncoming current spikes; typically utilizes a
The controller is manufactured by the in China. You will find it labeled with a few different, but similar, model numbers:
Are you attempting to on your JYMC-220BI board, or are you looking to wire it up to a specific machine? JYMC Variable Speed DC Motor Controls - Circuits Online
Terminals used for safety or emergency stop circuits to reduce output voltage to zero instantly. Key Technical Specifications Specification Input Voltage 230VAC, 50/60Hz Output Voltage Rated Current Protection MOV transient protection & electronic current limiting (CL) Adjustment Acceleration start (adjustable 0.5 to 4 seconds) On-Board Tuning Potentiometers