{"product_id":"2-pcs-ssr40dd-solid-state-relay","title":"SSR-40DD DC to DC Solid State Relay - 2 Pack","description":"\u003ch2\u003eSSR-40DD Solid State Relay\u003c\/h2\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompletely Silent Operation:\u003c\/strong\u003e Unlike traditional mechanical relays, this Solid State Relay (SSR) uses internal semiconductors to switch the load. This means zero clicking noises, zero mechanical wear, and zero electrical arcing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOpto-Isolated Safety:\u003c\/strong\u003e Features internal optical isolation between the low-voltage control circuit and the high-voltage load circuit, completely protecting your sensitive microcontrollers or PLCs from high-voltage spikes and feedback.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Speed Switching:\u003c\/strong\u003e Capable of turning on and off infinitely faster than a mechanical switch, making it highly suitable for precise PID temperature control and PWM (Pulse Width Modulation) applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable Epoxy Housing:\u003c\/strong\u003e The internal components are heavily potted in a flame-retardant industrial epoxy resin, making the relay highly resistant to severe vibration, moisture, and dust.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective Safety Cover:\u003c\/strong\u003e Includes a clear, flip-up polycarbonate safety shield over the screw terminals to prevent accidental short circuits or dangerous physical contact with live DC wires.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eProduct Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelay Type:\u003c\/strong\u003e DC-to-DC (DC Input controls a DC Load).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel Number:\u003c\/strong\u003e SSR-40DD.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eControl Input Voltage:\u003c\/strong\u003e 3V to 32V DC.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLoad Output Voltage:\u003c\/strong\u003e 5V to 200V DC.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum Load Current:\u003c\/strong\u003e 40 Amps (Requires adequate heatsink).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOn-State Voltage Drop:\u003c\/strong\u003e ≤ 1.5V.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eUniversal Compatibility \u0026amp; Applications\u003c\/h3\u003e\n\u003cp\u003eThis heavy-duty DC solid state relay is a staple for custom power control and industrial automation:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeated Beds (3D Printing):\u003c\/strong\u003e Frequently used to safely route heavy DC current from a power supply to a 3D printer's heated bed, bypassing the fragile motherboard MOSFETs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSolar \u0026amp; Battery Systems:\u003c\/strong\u003e Excellent for custom charge controllers, battery disconnects, or switching heavy DC solar panel arrays.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDC Motor Control:\u003c\/strong\u003e Used to switch high-torque brushed DC motors in robotics, CNC machines, or industrial actuators.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Power LED Arrays:\u003c\/strong\u003e Perfect for PWM dimming of large 12V or 24V LED lighting banks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhen to Use or Upgrade\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical Relay Failure:\u003c\/strong\u003e If your standard mechanical relay has welded its contacts shut from high-current arcing, upgrading to an SSR completely eliminates this failure point.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelay Stuck \"On\":\u003c\/strong\u003e When an SSR fails, it almost always fails in the \"closed\" (always on) position. If your heated bed or motor refuses to shut off even when the control signal is removed, the internal triac has burned out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSwitching Speeds:\u003c\/strong\u003e If your project requires a switch to toggle multiple times per second (like a PID temperature loop), a mechanical relay will physically break in a few days. An SSR is required.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eInstallation \u0026amp; Wiring Tips\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeatsink is MANDATORY (\u003c\/strong\u003e\u003cstrong\u003eCRITICAL):\u003c\/strong\u003e SSRs generate significant heat. If you are drawing more than 10 Amps continuously, you \u003cstrong\u003emust\u003c\/strong\u003e mount this relay to an aluminum heatsink. Pushing 40A without a heatsink will literally melt the relay and cause a fire.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThermal Paste:\u003c\/strong\u003e Always apply a thin, even layer of thermal compound (PC processor paste) between the metal bottom of the relay and the aluminum heatsink for proper heat transfer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrict DC Polarity:\u003c\/strong\u003e Unlike AC relays, DC relays are strictly polarized. You must carefully observe the Positive (+) and Negative (-) markings on both the Input (control) and Output (load) sides. Wiring the load backward will destroy the relay instantly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLoad Derating (\u003c\/strong\u003e\u003cstrong\u003ePRO TIP):\u003c\/strong\u003e For inductive loads (like heavy DC motors with magnetic coils), the starting current spikes massively. It is highly recommended to derate the relay and only run inductive loads at 50% of the maximum rating (i.e., keep continuous motor loads under 20A for a 40A relay).\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"BlueStarsParts","offers":[{"title":"Default Title","offer_id":45844235747517,"sku":"AZ00112969","price":20.51,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2576\/7548\/files\/AZ00115897_1_539f453c-f4e3-4cf0-ab59-a8d9f5eadc5d.jpg?v=1762245732","url":"https:\/\/bluestarspartstrend.com\/products\/2-pcs-ssr40dd-solid-state-relay","provider":"BlueStars Parts","version":"1.0","type":"link"}