Products

DescriptionWhen your hardware design requires switching serious power—like turning on a water pump, activating a heavy-duty solenoid, or managing 12V electric motorcycle lighting systems—you need an electromechanical relay. The 12V SPDT Songle Relay is a tried-and-true workhorse in the maker and industrial community, offering excellent power isolation in a highly compact footprint.Understanding the 5-Pin SPDT LayoutThis relay features a Single Pole Double Throw (SPDT) configuration, which gives you maximum flexibility in how you route power. The bottom features 5 pins:Coil Pins (x2): Apply 12V across these two pins to magnetize the internal coil and trigger the switch.Common (COM): The main power input for the heavy load you want to control.Normally Closed (NC): When the relay is OFF, power flows freely from COM to NC. When the relay triggers, this connection breaks.Normally Open (NO): When the relay is OFF, this pin is disconnected. When the relay triggers, power flows from COM to NO, turning your appliance on.Circuit Design Warning (The Bare Relay)As shown in the product image, this is the bare relay component, not a pre-built module. You cannot drive this directly from an Arduino or ESP32 GPIO pin. To use this relay on a custom PCB, you must design a small driver circuit:Transistor: You need an NPN transistor (like a BC547 or 2N2219) to act as a logic switch, using your microcontroller’s 3.3V/5V signal to switch the 12V required by the relay coil.Flyback Diode: You must wire a rectifier diode (like the 1N4004) in reverse parallel across the relay’s coil pins. When the magnetic field in the coil collapses, it generates a massive voltage spike. The diode safely shunts this spike, protecting your delicate silicon chips.Key Features:Fully Sealed: The blue plastic housing protects the internal mechanical contacts from dust, moisture, and corrosion.Audible Feedback: Provides a distinct, satisfying “click” when triggered, making hardware troubleshooting incredibly easy.High Isolation: Physically separates your low-voltage digital logic from dangerous high-voltage lines.Technical Specifications:Part Number: SRD-12VDC-SL-CNominal Coil Voltage: 12V DCCoil Resistance: ~400ΩMaximum AC Contact Rating: 10A @ 250V AC / 10A @ 125V ACMaximum DC Contact Rating: 10A @ 30V DC / 10A @ 28V DCContact Resistance: ≤ 100mΩElectrical Life: 100,000 cycles (at rated load)Package Form: 5-Pin DIP (Through-hole)Ideal Applications:Custom PCBs for IoT smart boxes and home automation hubs12V automotive and electric motorcycle accessory switchingSafely controlling 220V AC household appliances (fans, heaters, lamps)Reversing DC motor polarity (requires using two relays together)