Accepts standard 110V or 220V AC power (depending on the specific board variant and jumper configuration). Bridge Rectifier: Converts AC input into pulsating DC.
Main single-phase supply input. Make sure your board configuration matches your regional voltage profile (115V vs 230V).
: Look for an electrical short in the primary bridge rectifier or check if the motor armature has shorted internally.
Fine-tunes the speed regulation circuit relative to mechanical load fluctuations. If you notice your lathe significantly losing cutting speed as soon as a lathe tool meets metal stock, increase the IR compensation trimmer slightly to help the board automatically stabilize its RPM output under load. Troubleshooting Common Failure Modes
Key forums that have discussed the JYMC-220 series include: jymc220bi schematic full
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
Caps the absolute upper voltage ceiling. With the external speed dial cranked all the way up, adjust this trimpot until the armature output matches your motor's maximum structural faceplate specifications (either 90V DC or 180V DC). Warning: Over-adjusting this setting risks exploding the motor's carbon brushes.
Large electrolytic smoothing capacitors smooth out the ripple voltage, creating a high-voltage DC bus (approx. 150V–310V DC depending on input AC). 2. Low-Voltage Power Supply (LVPS)
Carbon tracks inside the pots are worn out or dirty. Clean with contact cleaner. Step-by-Step Diagnostic and Repair Roadmap Accepts standard 110V or 220V AC power (depending
The JYMC-220B-I Go to product viewer dialog for this item.
Used to electronically stop the motor without cutting main power. 3. Common Repair Scenarios
The controller is manufactured by the in China. You will find it labeled with a few different, but similar, model numbers:
: Often integrated with a separate forward/reverse switch to swap polarity to the motor. Common Components in the Schematic Make sure your board configuration matches your regional
JYMC-220B-I is a sophisticated DC brush motor speed controller, primarily utilized in high-torque industrial and hobbyist applications such as the Weiss Machinery mini lathes (e.g.,
The schematic of the JYMC-220B-I is built around a pulse-width modulation (PWM) or SCR-based rectification system (often using components) to convert AC input into a variable DC output. AliExpress Control and Feedback Loop The board utilizes an LM324 quad operational amplifier
: Sets the baseline starting voltage when the main speed knob is barely cracked open. Tweak this so the motor starts rotating smoothly without humming or stalling out.