{"product_id":"5v-4-channel-relay-shield-module-for-arduino-uno-r3-arm-pic-avr-dsp-electronic-4-way-four-channel-relay-control-expansion-board","title":"5V 4-Channel Relay Shield Module for Arduino UNO R3","description":"\u003cp\u003eFour switched circuits from one small board. This 5V relay shield plugs onto an Arduino UNO R3 footprint, so a sketch can switch lights, pumps or workshop gear instead of you reaching for four separate switches. Each channel has its own screw terminals and red indicator. Built for hobbyists and small automation builds.\u003c\/p\u003e\u003ch2\u003eFour relays, one shield, fewer loose wires\u003c\/h2\u003e\u003cp style=\"margin:0 0 6px 0\"\u003e✅ \u003cstrong\u003eSwitches four circuits independently\u003c\/strong\u003e Four relays on one board, each with its own NO, NC and COM screw terminal pair.\u003c\/p\u003e\u003cp style=\"margin:0 0 6px 0\"\u003e✅ \u003cstrong\u003eShows which channel is live\u003c\/strong\u003e A red LED sits beside each relay and lights when that channel is driven high.\u003c\/p\u003e\u003cp style=\"margin:0 0 6px 0\"\u003e✅ \u003cstrong\u003eFits the UNO shield footprint\u003c\/strong\u003e Standard shield shape and headers mean it plugs straight in, with no patch cables to trace.\u003c\/p\u003e\u003cp style=\"margin:0 0 6px 0\"\u003e✅ \u003cstrong\u003eStack another board on top\u003c\/strong\u003e The headers let you keep stacking expansion boards for the next stage of the build.\u003c\/p\u003e\u003cp style=\"margin:0 0 6px 0\"\u003e✅ \u003cstrong\u003eWorks with either logic level\u003c\/strong\u003e A high signal from 5V or 3.3V boards closes the relay, so mixed setups work.\u003c\/p\u003e\u003cp\u003eWiring is the part that eats an evening, so every connection lands on a screw terminal: strip the wire, clamp it, and that channel is done. The three contacts per relay cover the usual two cases, switching a load on when the sketch drives the pin high, or leaving it on until it does. Number the channels before you mount the board; the relay numbering is printed on it.\u003c\/p\u003e\u003cp\u003eThe coil side has its own 5V DC barrel jack, which gives you the option of feeding the relays from a separate supply instead of pulling everything through the host board. That helps when four relays switch at the same moment and the rest of the build is already drawing current.\u003c\/p\u003e\u003cp\u003eOne check before ordering: this is a shield, so it expects a board built to the UNO R3 outline, and the same footprint is used by many ARM, PIC, AVR and DSP boards. The three M3 holes let you fix the stack to a panel or a printed bracket rather than leaving it loose on the bench.\u003c\/p\u003e\u003cp\u003eKeep the green terminal blocks clear of a metal shell or housing when the stack is powered. With a UNO underneath, the USB connector stands proud of the board, so a tight case can touch the terminals and short them.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eTechnical details\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eSupply voltage: 5V DC\u003c\/li\u003e\n\u003cli\u003eChannels: 4 independent relays\u003c\/li\u003e\n\u003cli\u003eRelay type: HJR-4102-L-5V, 5V DC coil\u003c\/li\u003e\n\u003cli\u003eContacts per channel: NO, NC and COM screw terminals\u003c\/li\u003e\n\u003cli\u003eIndicators: one red LED per channel\u003c\/li\u003e\n\u003cli\u003eControl signal: high-level drive, 5V or 3.3V logic\u003c\/li\u003e\n\u003cli\u003eMounting: 3 x M3 screw holes\u003c\/li\u003e\n\u003cli\u003eBoard format: Arduino UNO R3 shield outline, stackable\u003c\/li\u003e\n\u003cli\u003ePower input: 5V DC barrel jack\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg class=\"detail-desc-decorate-image\" src=\"https:\/\/ae01.alicdn.com\/kf\/Se287536228ba4618a4878e792cef0405z.png\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg class=\"detail-desc-decorate-image\" src=\"https:\/\/ae01.alicdn.com\/kf\/S08640e1144bd4780956606726bd963344.jpg\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg class=\"detail-desc-decorate-image\" src=\"http:\/\/ae01.alicdn.com\/kf\/HTB1F08Sd8USMeJjy1zjq6A0dXXad.jpg\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg class=\"detail-desc-decorate-image\" src=\"http:\/\/ae01.alicdn.com\/kf\/HTB1N054gEUIL1JjSZFrq6z3xFXaz.jpg\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg class=\"detail-desc-decorate-image\" src=\"http:\/\/ae01.alicdn.com\/kf\/HTB1EPAqXPuhSKJjSspjq6Ai8VXaB.jpg\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg class=\"detail-desc-decorate-image\" src=\"http:\/\/ae01.alicdn.com\/kf\/HTB1wZJHf.l7MKJjSZFDq6yOEpXag.jpg\" slate-data-type=\"image\"\u003e\u003c\/p\u003e\u003cp\u003ePick the relay shield for the UNO project on your bench, then check your logic level before wiring.\u003c\/p\u003e\u003cp\u003eSee more: \u003ca href=\"https:\/\/spy-shop.com\/collections\/smart-home\"\u003eexplore more smart home control boards\u003c\/a\u003e\u003c\/p\u003e","brand":"Spy-shop.com","offers":[{"title":"Default Title","offer_id":64123874804042,"sku":"1005007596976882-Default Title","price":25.24,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0764\/5980\/2954\/files\/S028e279180bd42a78e9d4e53f1fc0979D.webp?v=1793320773","url":"https:\/\/spy-shop.com\/sl\/products\/5v-4-channel-relay-shield-module-for-arduino-uno-r3-arm-pic-avr-dsp-electronic-4-way-four-channel-relay-control-expansion-board","provider":"Spy-shop.com","version":"1.0","type":"link"}