C37 Single Relay Board for CNC Accessory Control

C37 Single Relay Board

The C37 Single Relay Board is a simple and reliable relay control board used to turn CNC accessories on and off from your control system. It allows a low-voltage CNC control signal to switch a separate AC or DC device, making it useful for controlling spindles, coolant pumps, contactors, valves, and other machine accessories.

This board is useful when your CNC controller or breakout board provides a TTL output signal, but the device you want to control requires a separate switched circuit. The C37 acts like an electrically controlled switch, allowing your CNC software or controller to activate external hardware safely and cleanly.

Why Choose the C37?

• Simple accessory control: Lets your CNC controller switch one independent AC or DC device on and off.
• Works with TTL control signals: Compatible with common +5VDC and +3.3VDC TTL-style CNC output signals.
• Useful for spindle and coolant control: Can be used to turn on a spindle circuit, coolant pump, contactor, valve, or other machine accessory.
• Screw terminal connections: Easy wiring with screw-on terminals for all connections.
• Works with common CNC control systems: Designed to interface with parallel-port style CNC control products and other compatible CNC4PC boards.
• Cleaner control box wiring: Provides a dedicated relay board instead of trying to switch accessory loads directly from a controller output.
• Good add-on board: A practical accessory for CNC builds that need one extra switched output.

Main Features

• Single independent relay output
• Controls one AC or DC device
• Compatible with TTL +5VDC or +3.3VDC signals
• Interfaces with parallel-port breakout boards and compatible CNC control boards
• Screw-on terminal connections
• Can be used as an electronically controlled switch
• Useful for powering or enabling external CNC hardware
• Works with many popular CNC hardware and software setups where compatible

Common Devices It Can Control

• Spindle on/off circuit
• Contactor for larger spindle systems
• Coolant pump
• Vacuum or dust collection trigger circuit
• Solenoid or electro valve
• Auxiliary machine accessories
• Other compatible AC or DC loads within relay limits

Relay Load Ratings

Customer-Friendly Explanation

Think of the C37 as a remote-controlled switch for your CNC machine. Your controller sends a small low-voltage signal, and the C37 uses that signal to switch another device on or off. This is useful because most CNC controllers should not directly power accessories like pumps, valves, or spindle circuits.

Use this board when you need one extra relay output for a CNC accessory and want a clean, simple way to wire it into your control box.

Common Uses

• Turning a spindle on or off
• Enabling a spindle contactor
• Turning coolant on or off
• Activating a solenoid valve
• Triggering a vacuum or dust collection system
• Switching one auxiliary CNC accessory
• Adding one relay-controlled output to a CNC control box

Official Documentation & User Manual

Compatibility Notes

• This board controls one independent AC or DC device.
• It is designed for compatible TTL +5VDC or +3.3VDC control signals.
• This is not a motion controller and not a motor driver.
• Use a properly rated contactor or external relay for loads that exceed the board’s relay rating.
• Confirm your controller output type, load voltage, load current, and wiring requirements before ordering.
• Electrical wiring should be performed by someone qualified to work with the voltages involved.

C37 Relay Board Buying Guidance

Choose the C37 if your CNC control system needs one simple relay-controlled output for a single accessory. It is a practical choice for spindle enable circuits, coolant pumps, solenoid valves, vacuum triggers, dust collection triggers, contactor control, and other CNC accessories that need on/off switching from a low-voltage controller signal.

The C37 is not a motion controller, motor driver, or power supply. It is a relay interface board. Your CNC controller provides the low-voltage TTL control signal, and the C37 relay switches the external accessory circuit. For high-current motors, pumps, or inductive loads, use the C37 to trigger a properly rated contactor or external relay instead of switching the full load directly.