Summary of Solar Tracker Relay circuit using Arduino
This article details a solar tracker project using an Arduino to control two motors via a 4-channel relay shield. The author switched from an H-bridge to relays for reliable forward and reverse motor control. The setup requires a separate 12V DC power supply for the motors, while the Arduino provides 5V logic to drive the relays. Adjusting the external voltage allows users to modify motor speed.
Parts used in the Solar Tracker Relay Project:
- Arduino
- 4 Channel Relay Shield
- Motor 1
- Linear Actuator (Motor 2)
- 12V DC Power Supply
- Circuit components for wiring
I’ve reached the point where I need to think how I’m going to control the motor & linear actuator for my solar tracker.
Things to consider –
Must be able to go forwards and backwards – so that makes 4 channels, 2 for each motor.
Must be able to provide enough power to drive the motors.
Originally I looked at an H-Bridge Circuit, and I did buy one, but I had lots of problems with getting it to reverse the motors, so I gave up.
I’ve now decided Relays are the way to go.
I bought this relay shield from Ebay for about £6.
It’s 4 channels and is very well built.
Relays are easily driven from the 5volts off the Arduino.
Here is circuit diagram for the 4 Channel Relay module.
It’s pretty easy to connect up.
The arduino supplies power to the relay switches, but not the motors.
You need to connect a power supply to the other side of the relays. I use a 12V DC power supply, but you could use whatever you like.
Tip! – You could alter the voltage of this power supply to speed up or slow down your motors.
Remember – If you want a bigger diagram, please fill out your email address on the left and I’ll happily send you a larger version of this image plus loads of others.
Here you can see a picture of it all connected.
There is only one motor connected as I was testing at this stage
For more detail: Solar Tracker Relay circuit
- Why did the author switch from an H-Bridge circuit to relays?
The author abandoned the H-Bridge because they experienced significant problems getting it to reverse the motors. - How many channels does the chosen relay shield have?
The relay shield purchased from eBay has 4 channels. - What voltage does the Arduino use to drive the relay switches?
The Arduino supplies 5 volts to drive the relay switches. - Does the Arduino provide power to the motors directly?
No, the Arduino supplies power to the relay switches but not the motors. - What type of power supply is recommended for the motors?
A 12V DC power supply is used, though any suitable voltage can be connected to the other side of the relays. - Can the motor speed be adjusted in this setup?
Yes, altering the voltage of the external power supply will speed up or slow down the motors. - How many motors are required for this specific solar tracker configuration?
The project requires two motors, with 2 channels dedicated to each motor for forward and backward movement.
