Need help with a 6 actuator setup

Projects General Guidance
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Hello everyone! An absolute newbie here. My team and I are trying to build a sensory Braille Reader using linear actuators. Although this is a project that's been done multiple times before, we're running into a lot of hardware relateed problems. To preface this, here is the list of components we are using:

  1. Linear Actuators: JF-0630B (12VDC, 2A)
  2. Arduino Uno R3
  3. 4-Channel Relay Modules: JQC-3F-05VDC-C
  4. Power is obtained from a direct power supply (wall plug point).

When we first began, we faced an issue with the overheating of the actuators, for which we decided to add in a cooling fan on the advice of a professor. Not sure to what extent this is actually helping since we have not been able to test the actuators working for a long period of time due to the other issues that have come up.

On trying to connect two actuators using the relay modules, we turned on the power supply while the circuit was connected to my laptop. Something in the circuit started to buzz and made a sort of distressed sound, and my laptop immediately shut down. When I powered it back up, the USB port it was connected to no longer worked and the microcontroller chip of the Arduino board began to heat up. That board stopped working and we've got another now. We tested the same circuit using a desktop CPU and that seemed to run just fine, but there is a slight buzzing sound, coming either from the Arduino board or the relays, we're not sure.

After talking to another professor, we realised it might be because the direct power supply coming in was of 12V, which the Arduino wouldn't be able to handle. It was suggested that we find a different microcontroller board, like a Raspberry Pi but that would be out of our budget.

Instead we were wondering if it would be smarter to buy linear actuators that only required 5VDC to activate (like this one: https://kitsguru.com/products/dc-5v-force-0-2n-5n-solenoid-pull-push-long-stroke-electromagnet-industrial-grade?variant=46374667976956&country=IN&currency=INR&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1). Would that work better? Or is there any way to handle the back voltage in a way that doesn't damage any of our components or our laptops? We've also only been able to connect 2 linear actuators so far, is there any way we can safely connect all six required for a Braille Display?

Attaching a very rough image of the circuit, if the connections aren't clear enough please let me know.

Screenshot 2025-06-25 230723
Screenshot 2025-06-25 2307231112×710 112 KB

Any and all help is appreciated. Thanks for reading!

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  • Suggest Arduino be powered thru the USB connector so there is no 5v feedback to PC.
  • Solenoids need kickback diodes.
  1. Linear Actuators: JF-0630B (12VDC, 2A)

  • The way you show the 12V solenoids being powered you will short Arduino and relay board 5v to 12V.

  • Arduino, relay boards and 12v solenoids need separate power.

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First, I can find NO solenoids with that number that require 12 volts at 2A. All are less than 1A. Some 300ma units.

Second, and most important, These all need to be mounted on a heat sink so the heat can be dissipated. Preferably aluminum, perhaps 1/8 inch thick. You are using the solenoids in continuous service!

Third, since you are using relays, assuming connecting the CO, common to one side of the 12 volts, and the NO, normally open contact to the other side of 12 volts. There is absolutely no reason to connect any part of the 12 volts to any part of your Arduino board.

Forth, Braille readers read words, not individual letters. So you need an array of at least 12 sets, possible 24 sets of actuators/solenoids to make a Braille reader.

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This will help you from doing damage to this and future projects.
Gil's Crispy Critter

Gil's Crispy Critter Rules for Processor Hardware:

  1. Rule #1: An Arduino is NOT a Power Supply!
  2. Rule #2: Never connect anything inductive (motors, speakers) directly to an Arduino!
  3. Rule #3: Avoid connecting or disconnecting wires while the power is on.
  4. Rule #4: Do not apply power to any pin unless you are certain of what you're doing.
  5. Rule #5: Do not exceed the maximum voltage ratings.
  6. Rule #6: Many Arduinos cannot power transmitters directly.
  7. Rule #7: Before powering your project, take a break and double-check the wiring.

LaryD’s Corollaries:

  1. Coro #1: When starting out, add a 220Ω resistor in series with both input and output pins to protect against shorts.
  2. Coro #2: Invest in a Digital Multi-Meter (DMM) to measure voltages, currents, and resistance.

Note: Violating these rules can turn your Arduinos into crispy critters. For optimal performance, keep your wires under 25 cm (10 inches).

Additional Tips:

  • The L293 motor driver, though common, is inefficient as it can lose around 3V as heat when driving both legs of a motor. Consider using a motor driver with MOSFET outputs to reduce heat loss and conserve battery power.
  • For more on powering Arduino boards, explore this guide: Powering Alternatives for Arduino Boards.
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Protect GPIOs
Protect GPIOs1457×879 208 KB

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