Conecting a relay - General Electronics - Arduino Forum
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I've noticed in several pictures that a relay is controlled by the arduino by connecting the 5v arduino pin to the relay and the ground is connected through a transistor, with is controlled by another pin on the arduino. In other pictures I se that a normal output pin from the arduino is connected to the relay, and no transistor is used. What is the difference between these two approaches. Is there an advantage in using the transistor, or are these just two ways of doing the same thing? I put tw
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Hooking up relay to Arduino - General Electronics - Arduino Forum
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Switching the relay will cause false pulses on another digital input - Hardware - Arduino Forum
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Switch hookup with relay (arduino)
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Relay jumper isolation - General Electronics - Arduino Forum
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Simple bypass button for relay - General Electronics - Arduino Forum
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Problem with relay - Hardware - Arduino Forum
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Wiring a Opto-Isolated Relay to Arduino - #19 by timmorn - General Electronics - Arduino Forum
![](https://i0.wp.com/randomnerdtutorials.com/wp-content/uploads/2016/12/relay-module-pinout.jpg?resize=712%2C310&quality=100&strip=all&ssl=1)
Guide for Relay Module with Arduino
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Schematic Help - General Electronics - Arduino Forum
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Is there a way to use the pwm directly as the relay or how to simplify many re? - General Electronics - Arduino Forum
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Input on Relay: The control of loop of earth wire - General Electronics - Arduino Forum
![](https://europe1.discourse-cdn.com/arduino/original/4X/7/d/1/7d1bca84970ff56fba5de7622449bbce2abbd086.png)
NodeMCU with 5V relay - #33 by dlloyd - General Electronics - Arduino Forum