I'm trying to set up an arduino mega with a DC House mini linear actuator. The only function I need is for the actuator to extend when certain logic is met and then retract when certain logic is met on the arduino.
When I see tutorials on using linear actuators with arduino, it seems like folks always have a motor driver/controller, but they are also concerned with things like tracking the position, speed, and force of the actuator.
My question is, couldn't I just use 5v relays to get the functionality I want from the actuator along with a 12v battery if all I need it to do is extend and retract at full speed when I send a signal to it?
If so, how could I do the wiring on the relays (and is it safe to do so)?
If not, could anyone recommend a simple and reliable motor controller for the limited functionality I need?
My biggest concern with this project is voltage overloads or overheating since this machine needs to do its thing for years without me around to do maintenance on it.
Yes. Although it might make more sense to use 12V relays.
Use 2x relays. Connect the NO terminals to 12V and the NC terminals to ground. Connect the actuator to the 2x COM terminals. This is how you make an "H-bridge" with relays.
You should probably also add flyback diodes, especially if the 12V supply shares a common ground with the Arduino. Use 4x diodes (eg. 1N400x) in a diode-bridge configuration to ensure any reverse voltage is dealt with safely.
Maybe relays are not the best choice. They are mechanical and will eventually wear out. Solid-state H-bridges should last longer, if they are properly chosen and connected. Give more details about your actuator.
I'm not sure what info might be most relevant, so here is the actual model of actuator I'm using.
For more details about the build, I have 3 photoresistors connected to the arduino. When they become exposed to light in a specific order, it causes a servo to rotate. All of that works currently, but I need to add some linear motion to lower the servo before it spins, so I'm adding a linear actuator that retracts before the servo motion, and extends when the servo is done rotating.
I'm not opposed to using a motor controller/driver for the actuator, but I have 5v relays laying around, so I was going to save myself the wait time. If there is a model of controller or Solid-State H-Bridge that you like, feel free to drop a model ID here and I can get one ordered and just wait a couple of days to complete this build.
The reason for the no maintenance is that it is for a business and I'm moving soon to open up another location, so I won't have anyone on site who knows anything about electronics. Mostly just need something that won't explode, catch fire, (or if I'm lucky) break down if no one is paying attention to it for a few years.
Those should be fine, IF the contacts are rated for the linear actuator stall current. Unfortunately the seller does not seem the offer that information.
I would not have purchased from that vendor because they don't mention the current/power drawn by the actuator. If it was incredibly inefficient and draws 50 Amps, you would have no grounds to complain. It almost certainly won't do that, but giving no detail of current/power means that you can't choose a suitable driver, and your only safe option is to use their recommended driver.
Oh well, you have it now, so you can measure the current drawn yourself, both the load current and the stall current.
