{"product_id":"c37-single-relay-board-for-cnc-accessory-control","title":"C37 Single Relay Board for CNC Accessory Control","description":"\u003cdiv style=\"font-family: Arial, sans-serif; line-height: 1.6; color: #222;\"\u003e\n\n  \u003ch2 style=\"font-size: 24px; margin-bottom: 10px;\"\u003eC37 Single Relay Board\u003c\/h2\u003e\n\n  \u003cp style=\"font-size: 16px; margin-bottom: 18px;\"\u003e\n    The \u003cstrong\u003eC37 Single Relay Board\u003c\/strong\u003e 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.\n  \u003c\/p\u003e\n\n  \u003cp style=\"font-size: 16px; margin-bottom: 18px;\"\u003e\n    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.\n  \u003c\/p\u003e\n\n  \u003cdiv style=\"background: #f6f6f6; border-left: 4px solid #333; padding: 15px 18px; margin: 22px 0;\"\u003e\n    \u003cstrong\u003eBest for:\u003c\/strong\u003e CNC routers, CNC mills, plasma tables, spindle on\/off control, coolant pump control, contactor control, solenoid valves, vacuum systems, and other CNC accessories that need simple relay switching.\n  \u003c\/div\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eWhy Choose the C37?\u003c\/h3\u003e\n\n  \u003cul style=\"padding-left: 22px; margin-bottom: 22px;\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSimple accessory control:\u003c\/strong\u003e Lets your CNC controller switch one independent AC or DC device on and off.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWorks with TTL control signals:\u003c\/strong\u003e Compatible with common +5VDC and +3.3VDC TTL-style CNC output signals.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eUseful for spindle and coolant control:\u003c\/strong\u003e Can be used to turn on a spindle circuit, coolant pump, contactor, valve, or other machine accessory.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eScrew terminal connections:\u003c\/strong\u003e Easy wiring with screw-on terminals for all connections.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWorks with common CNC control systems:\u003c\/strong\u003e Designed to interface with parallel-port style CNC control products and other compatible CNC4PC boards.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCleaner control box wiring:\u003c\/strong\u003e Provides a dedicated relay board instead of trying to switch accessory loads directly from a controller output.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eGood add-on board:\u003c\/strong\u003e A practical accessory for CNC builds that need one extra switched output.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eMain Features\u003c\/h3\u003e\n\n  \u003cul style=\"padding-left: 22px; margin-bottom: 22px;\"\u003e\n    \u003cli\u003eSingle independent relay output\u003c\/li\u003e\n    \u003cli\u003eControls one AC or DC device\u003c\/li\u003e\n    \u003cli\u003eCompatible with TTL +5VDC or +3.3VDC signals\u003c\/li\u003e\n    \u003cli\u003eInterfaces with parallel-port breakout boards and compatible CNC control boards\u003c\/li\u003e\n    \u003cli\u003eScrew-on terminal connections\u003c\/li\u003e\n    \u003cli\u003eCan be used as an electronically controlled switch\u003c\/li\u003e\n    \u003cli\u003eUseful for powering or enabling external CNC hardware\u003c\/li\u003e\n    \u003cli\u003eWorks with many popular CNC hardware and software setups where compatible\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eCommon Devices It Can Control\u003c\/h3\u003e\n\n  \u003cul style=\"padding-left: 22px; margin-bottom: 22px;\"\u003e\n    \u003cli\u003eSpindle on\/off circuit\u003c\/li\u003e\n    \u003cli\u003eContactor for larger spindle systems\u003c\/li\u003e\n    \u003cli\u003eCoolant pump\u003c\/li\u003e\n    \u003cli\u003eVacuum or dust collection trigger circuit\u003c\/li\u003e\n    \u003cli\u003eSolenoid or electro valve\u003c\/li\u003e\n    \u003cli\u003eAuxiliary machine accessories\u003c\/li\u003e\n    \u003cli\u003eOther compatible AC or DC loads within relay limits\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eRelay Load Ratings\u003c\/h3\u003e\n\n  \u003cdiv style=\"overflow-x: auto; margin-bottom: 22px;\"\u003e\n    \u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 15px;\"\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align: left; border: 1px solid #ddd; padding: 10px; background: #f2f2f2;\"\u003eLoad Type\u003c\/th\u003e\n        \u003cth style=\"text-align: left; border: 1px solid #ddd; padding: 10px; background: #f2f2f2;\"\u003eMaximum Relay Rating\u003c\/th\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"border: 1px solid #ddd; padding: 10px;\"\u003eDC Load\u003c\/td\u003e\n        \u003ctd style=\"border: 1px solid #ddd; padding: 10px;\"\u003eUp to 10A at 28VDC\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"border: 1px solid #ddd; padding: 10px;\"\u003eAC Load\u003c\/td\u003e\n        \u003ctd style=\"border: 1px solid #ddd; padding: 10px;\"\u003eUp to 10A at 125VAC\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"border: 1px solid #ddd; padding: 10px;\"\u003eAC Load\u003c\/td\u003e\n        \u003ctd style=\"border: 1px solid #ddd; padding: 10px;\"\u003eUp to 6A at 220VAC\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv style=\"background: #fff8e5; border: 1px solid #e0c878; padding: 15px 18px; margin: 22px 0;\"\u003e\n    \u003cstrong\u003eImportant:\u003c\/strong\u003e\n    \u003cp style=\"margin: 8px 0 0 0;\"\u003e\n      Motors and inductive loads can draw significantly more current during startup than their normal running current. Always size relays, contactors, wiring, and protection devices properly for your application.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eCustomer-Friendly Explanation\u003c\/h3\u003e\n\n  \u003cp style=\"font-size: 16px; margin-bottom: 18px;\"\u003e\n    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.\n  \u003c\/p\u003e\n\n  \u003cp style=\"font-size: 16px; margin-bottom: 18px;\"\u003e\n    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.\n  \u003c\/p\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eCommon Uses\u003c\/h3\u003e\n\n  \u003cul style=\"padding-left: 22px; margin-bottom: 22px;\"\u003e\n    \u003cli\u003eTurning a spindle on or off\u003c\/li\u003e\n    \u003cli\u003eEnabling a spindle contactor\u003c\/li\u003e\n    \u003cli\u003eTurning coolant on or off\u003c\/li\u003e\n    \u003cli\u003eActivating a solenoid valve\u003c\/li\u003e\n    \u003cli\u003eTriggering a vacuum or dust collection system\u003c\/li\u003e\n    \u003cli\u003eSwitching one auxiliary CNC accessory\u003c\/li\u003e\n    \u003cli\u003eAdding one relay-controlled output to a CNC control box\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eOfficial Documentation \u0026amp; User Manual\u003c\/h3\u003e\n\n  \u003cdiv style=\"background: #f6f6f6; border-left: 4px solid #333; padding: 18px 20px; margin: 22px 0;\"\u003e\n    \u003cp style=\"font-size: 16px; margin: 0 0 16px 0;\"\u003e\n      Review the official C37 user manual before wiring this single relay board into your CNC control box. The manual can help with relay wiring, input signal requirements, load connections, and safe installation planning for CNC accessory switching.\n    \u003c\/p\u003e\n\n    \u003cdiv style=\"display: flex; flex-wrap: wrap; gap: 10px;\"\u003e\n      \u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0664\/7516\/3822\/files\/User_Manual5.pdf?v=1779235501\" target=\"_blank\" rel=\"noopener\" style=\"display:inline-block;background:#111;color:#fff;text-decoration:none;font-weight:700;border-radius:8px;padding:13px 16px;font-size:15px;line-height:20px;\"\u003e\n        View C37 User Manual\n      \u003c\/a\u003e\n    \u003c\/div\u003e\n\n    \u003cp style=\"font-size: 13px; color: #555; margin: 14px 0 0 0;\"\u003e\n      Documentation may include relay wiring, control signal information, load connection details, installation notes, and technical reference material. Always confirm your CNC controller output type, accessory voltage, current draw, relay rating, and wiring plan before powering the system.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eCompatibility Notes\u003c\/h3\u003e\n\n  \u003cul style=\"padding-left: 22px; margin-bottom: 22px;\"\u003e\n    \u003cli\u003eThis board controls \u003cstrong\u003eone independent AC or DC device\u003c\/strong\u003e.\u003c\/li\u003e\n    \u003cli\u003eIt is designed for compatible TTL +5VDC or +3.3VDC control signals.\u003c\/li\u003e\n    \u003cli\u003eThis is \u003cstrong\u003enot a motion controller\u003c\/strong\u003e and \u003cstrong\u003enot a motor driver\u003c\/strong\u003e.\u003c\/li\u003e\n    \u003cli\u003eUse a properly rated contactor or external relay for loads that exceed the board’s relay rating.\u003c\/li\u003e\n    \u003cli\u003eConfirm your controller output type, load voltage, load current, and wiring requirements before ordering.\u003c\/li\u003e\n    \u003cli\u003eElectrical wiring should be performed by someone qualified to work with the voltages involved.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n\n  \u003ch3 style=\"font-size: 20px; margin-top: 28px;\"\u003eC37 Relay Board Buying Guidance\u003c\/h3\u003e\n\n  \u003cp style=\"font-size: 16px; margin-bottom: 18px;\"\u003e\n    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.\n  \u003c\/p\u003e\n\n  \u003cp style=\"font-size: 16px; margin-bottom: 18px;\"\u003e\n    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.\n  \u003c\/p\u003e\n\n  \u003cdiv style=\"background: #fff8e5; border: 1px solid #e0c878; padding: 15px 18px; margin-top: 24px;\"\u003e\n    \u003cstrong\u003eNeed help choosing the right relay board?\u003c\/strong\u003e\n    \u003cp style=\"margin: 8px 0 0 0;\"\u003e\n      If you are not sure whether the C37 is the right relay board for your CNC accessory, contact us before ordering. We can help you check the control signal, load type, voltage, and current requirements.\n    \u003c\/p\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"BuildYourCNC","offers":[{"title":"Default Title","offer_id":47832214700206,"sku":null,"price":13.18,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0664\/7516\/3822\/files\/C37_C37-SingleRelayBoard.webp?v=1778199385","url":"https:\/\/buildyourcnc.com\/products\/c37-single-relay-board-for-cnc-accessory-control","provider":"BuildYourCNC","version":"1.0","type":"link"}