Hello,
I'd like to control 2 12vDC linear actuators from an Arduino Uno in a project of an autonomous solar tracker for my solar pannels.
I'd like to know how to do this : does some kind of electronic switch exist which closes a circuit when it recieves the current of an output arduino pin ?
Or would I need some kindof amplifier ?
Hi,
Since this will not run the motors continuously, relay may be good and easy..
See THIS Page for some suggestions...
terryking228:
Hi,Since this will not run the motors continuously, relay may be good and easy..
See THIS Page for some suggestions...
Oh yes it looks like the perfect solution, thank you !
Bipattes:
it looks like the perfect solution
Depends what type of actuators you have. Post a link to them (see the "please read" post to find out how to correctly post links). Some linear actuators are like rotational servo motors in that they respond to a logic level pwm signal, which an Arduino can produce, so no relays would be required.
PaulRB:
Depends what type of actuators you have. Post a link to them (see the "please read" post to find out how to correctly post links). Some linear actuators are like rotational servo motors in that they respond to a logic level pwm signal, which an Arduino can produce, so no relays would be required.
I will most likely buy these types of actuators
Bipattes:
I will most likely buy these types of actuators
Ok, the cable has 2 conductors which tells us that they are the simple type, not the more convenient type I was describing.
You will need 4 relays rated for at least 3A @12V DC for your 2 actuators. Alternatively, you could use 2 x 2-channel motor drivers. But they will probably not be worth the extra expense.
You will also need to fit limit switches, so that the actuators do not burn out when they reach their extremes of motion.
PaulRB:
You will need 4 relays rated for at least 3A @12V DC for your 2 actuators. Alternatively, you could use 2 x 2-channel motor drivers. But they will probably not be worth the extra expense.You will also need to fit limit switches, so that the actuators do not burn out when they reach their extremes of motion.
Why don't I need 1 relay per actuator ?
For the switches these actuators have built-in ones, so this won't be a problem.
(UP) Why don't I need 1 relay per actuator ?
To run the motor in both directions, you need what is called an H- bridge. You can get H-bridge chips, or you can build them from MOSFETs, or you can use two spdt relays.
Do you need the Arduino to detect when the limit switches have been activated? If so, you will need a current sensor of some kind (the current will drop to nothing when one of the limit switches is activated).
Or a DPDT relay, and two transistors: one MOSFET for speed control, one NPN or MOSFET for coil/motor direction control:
PaulRB:
To run the motor in both directions, you need what is called an H- bridge. You can get H-bridge chips, or you can build them from MOSFETs, or you can use two spdt relays.
Oh yes I see, I odon't know how I didn't think about it.
PaulRB:
Do you need the Arduino to detect when the limit switches have been activated? If so, you will need a current sensor of some kind (the current will drop to nothing when one of the limit switches is activated).
I might need this because for exemple in winter, one linear actuator will stay in retracted position all the day, so if the actuator receives constantly 12v dc at 1 amp, wouldn't it waste some power ?
CrossRoads:
Or a DPDT relay, and two transistors: one MOSFET for speed control, one NPN or MOSFET for coil/motor direction control:
I'm quite a noob in electronics so your idea scares me a bit, but I don't think I will need this complex system because I don't need to change the actuators' speed, I will connect the relays and actuators to 12v dc at 1 amp power supplies constantly plugged in (I don't think it willl waste electricity when circuits will be open).
I agree, I do not think you need speed control, only direction control. You would wire your relays like this.
one linear actuator will stay in retracted position all the day, so if the actuator receives constantly 12v dc at 1 amp, wouldn't it waste some power ?
If you are correct about the limit switches, then no, the limit switch would cut the power to the motor.
Okay thanks PaulRB !
