Contents
How does a relay module work?
A power relay module is an electrical switch that is operated by an electromagnet. The electromagnet is activated by a separate low-power signal from a micro controller. When activated, the electromagnet pulls to either open or close an electrical circuit.
What is optical isolation relay?
Optically-isolated relays are characterized by the use of a light emitting diode (LED) on their input side, MOSFETs on the output side and an array of photo sensors in between. In operation, current flows through the LED, which then emits light.
What is optical isolation in PLC?
An opto-isolator (also called an optocoupler, photocoupler, or optical isolator) is an electronic component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal.
Can you control a relay module with Arduino?
Controlling a relay module with the Arduino is as simple as controlling an output – you just need to send HIGH or LOW signals using an Arduino digital pin. With the relay module you can control almost any AC electronics appliances (not just lamps).
How many pins does an Arduino relay have?
Some relay module only has two pin in high voltage group. The relay can work with two modes: normally open mode and normally closed mode. These modes are the opposite. The “normally” means “if IN pin is connected to LOW (0V)”. To use this mode, we need to connect the high voltage device to the COM pin and NO pin.
What are the pins on the relay module?
The following figure shows the relay module pinout. The six pins on the left side of the relay module connect high voltage, and the pins on the right side connect the component that requires low voltage—the Arduino pins. The high-voltage side has two connectors, each with three sockets: common (COM), normally closed (NC), and normally open (NO).
When to use NC or NC in Arduino relay?
NC (Normally Closed): the normally closed configuration is used when you want the relay to be closed by default, meaning the current is flowing unless you send a signal from the Arduino to the relay module to open the circuit and stop the current.