A relay will be necessary in cases where transistors cannot switch AC or high voltages like the mains electricity since they are not usually a good choice for switching large currents which is ...

Contribute to mistay/arduino_poe_ip_relay development by creating an account on GitHub. ... is delayed by a transistor (BD139) used as a switch. 3 LEDs indicate the status of this device: GREEN LED 1: ...

Electromechanical relays will require a transistor driver circuit in order to be driven by the Arduino. The typical circuit for driving a relay is the same as the transitor driver above with the ...

send SMS on SIM (inserted in SIM900), The relay should switch its state from OFF TO ON for 1 second and then again turn off. About This project uses GSM Module (SIM900) with Arduino to switch Relay ...

While transistors and relays are interchangeable in some situations, relays present some unique pros and cons. They can entirely isolate one circuit from another, meaning if you have a device you know ...