4 Channel Relay Board

This is an over-current trip switch. It provides protection to a load when over current condition occurs. Basically, the project trips the relay when there is a short circuit or the load starts drawing much current. When the condition is favorable, press the tactile switch to power the load again. The threshold voltage of the comparator is 0.6V, the over-current limit can be adjusted using the trimmer Potentiometer PR1. Operating supply 12V DC @ 80mA when the relay is ON, load supply 0V to 48V.

This RC Relay project enables control of large current devices using a Radio Control (RC) System. This RC switch converts hobby radio control (RC) pulses to control the on/off state of the Relay. On board LED indicates the output. The board is Arduino compatible and the example code can be modified as per user requirements.  The relay ON/OFF threshold can be set as per user requirements. The Arduino sample code enables momentary ON/OFF control of the relay, but this can be modified for Latch output. The relay can handle a load up to 7A – 30V DC or 7 Amps 230AC Loads such as bulbs, LEDs, motors, fans, heaters etc. The project can be connected to an unused RC channel. It operates with 5V DC and draws 60mA current when the relay is ON. 3 Pin male header helps the user to connect the RC receiver. The project is Arduino compatible and can be programmed using Arduino IDE with the help of an onboard programming connector. The project consists of an Atmega328 microcontroller, programming/bootloader connector, relay, BC847 BJT transistor to drive the relay, freewheel diode for protection from the relay, and U2 PC817 provides isolation between the microcontroller and relay. D1 LED indicates output, D3 LED power LED. connector CN2 relay switch connection, connector CN1 5V supply input.

This is an SPI Interface multichannel relay board for high voltage AC or low voltage DC loads. It is ideal for controlling LEDs lights, coffee machines, fans, pumps, or other high-voltage electrical appliances. The board also breaks out the SPI header, so controlling other boards is still possible. Each relay can handle current up to 7A @ 250V AC/30V DC. This 8 x channel board is mainly designed for AC loads, but it can also drive DC loads, screw terminals on each channel enable the easy interface of the AC load, and each point is marked as AC-Live and AC Neutral. Refer to the connection diagram for the interface. The project consists of 8 x 12V relays with load capacity 7A @ 250V AC, ULN2803 8 channel relay driver, 74HC595 SPI to 8 output, 5V regulator 7805, power LED, screw terminals for loads and AC input, header connector for SPI input and output.

2 channel Relay driver project can be controlled by feeding 2-12V trigger voltage, Very useful project for application like Micro-Controller based projects, Remote controller, Lamp on Off, and any circuits which required isolated high current and high voltage switching by applying any TTL or CMOS level voltage. Two LED works as operation indicator while in , 3 pins screw terminals to connect load and provides  both normally open and normally closed switching.