Linear actuators are mechanical devices that transform energy to create straight line motions. A relay, on the other hand, is a switch whose operations are electrical. This article teaches users how linear actuators are controlled by relay boards. The only difference in relay boards is the number of relays they carry since all relays’ action are the same.
To control two actuators in a MegaMoto control board, four relays are combined with the board. The relays on the board choose the direction while the board gives the actuators speed signals.
While creating an H-bridge for driving a motor at 10A for up to 30V, two relays can be used.
In the activation of an electromagnet, the input current is used by the relays. The work of the electromagnet is to pull the switch, one position to the next, allowing currents of a higher power on the relay’s other side to flow. In this way, an Arduino control side (small power current) can be able to control an actuator control (a large power circuit).
The following are required for this project:
One Arduino Uno, one relay board, one MegaMoto motor controller and M/F Jumper wires.
The first step is to wire the board basics. A GND pin is found on the relays on the control side. A Vcc pin follows the above, and then all the INx pins(1-8). For relays to hold active, a fair bit of power is taken by the relays. This is around 70 mA hence using a dedicated supply of 5V is advisable. In the case where all relays get active at once, the Arduino struggles to provide enough power.
The amount of power delivered by the Arduino depends on the powering of the Arduino. An Arduino providing a few hundred milliamps is a safe assumption. Two relays can thus be powered easily, a maybe goes for four relays, but an external supply is needed for eight relays.
On the control side, first connect to the relay board, GND pins and the Vcc, the 5V supply. Next, a connection of the INx pin is made to the Arduino pin that the user intends to use during the activation of the relay.
Diodes found beside the relays (D1, D2, D3) communicates the corresponding IN pin to each relay in the eight relay board. In the two relay board, while placing the Vcc and INx pins on the left and the GND being used as a basis of top and bottom, the top relay is the IN1, and the bottom one is the IN2. The board that has four relays is clearly labeled.
Connecting the corresponding INx pin to the GND activates the relays.
Next we will talk about the relay side. The common (COM) connection is the center screw. The Normally Open (NO) connection is at the bottom while, and we have the Normally Closed (NC) connection at the top.
In cases where no connections exist to the INx pins, the relay is only connected between the COM and NC. The relay will also be connected between the NC and COM if the user applies 5V to the INx pin. For the relay switch to make a connection between NO and COM, a connection has to be made from the INx pin to the GND.