Very new to the world of electronics so forgive any ignorance here.

I'm trying to control a hydraulic actuator that takes a 0-12V input signal. I'm using an ESP32 to give me a 3.3V PWM signal.

Originally, I was planning to use a D4184 MOSFET control module to convert the 3.3V signal into a 12V signal, but the load can pull up to 30 amperes and since the load ground has to be connected to the D4184 (based on the wiring instructions,) once I crank up the signal the high current feeds through the D4184 and fries it pretty quickly.

I have not been able to find any sort of MOSFET or logic level shifter that can take a 3.3V input and produce a 12V output while being able to handle such high current and maintain a reasonable voltage curve.

Additional info (I'm not sure if this is important or not but the more info the better!):

  • The MOSFET module and the hydraulic actuator are powered from the same 12V source.
  • The actuator has 3 wires: + power, signal, and ground.
  • The MOSFET module has 5 connections. One side has the input and ground for the 3.3V PWM signal. The other side has one connection for the 12V power source and actuator signal wire, one that connects to the load ground, and one that is the regular ground.
  • The D4184 has an optoisolator to isolate the microcontroller from the load which is nice as I don't want to fry it.

Maybe I am making a silly mistake with how everything is wired up in regards to the ground, but any suggestions for alternative parts or wiring schemes that solve my problem would be much appreciated.

EDIT: Apologies for the delay, here is more info on the parts:

D4184 MOSFET Control Module

Actuator (Ignore the breakaway switch portion as it's not applicable for how we're using the actuator.)

And here is how I think it was wired up, but there was quite the jungle of unrelated wires in the box and it took a few tries to get it to a point where the connections were functioning properly.

enter image description here

It feels strange having the positive lead of the battery connected to the load positive, the signal wire, and the D4184, which is why I figured I was having a novice misunderstanding. But from the descriptions in the wiring instructions that's the only way I could figure out how to interpret it. I was definitely unsure as it felt like I should be able to control the signal without having the entire load feed through the D4184, but I couldn't figure out how based on the wiring diagrams.


Thank you for the suggestions everyone! I decided to try the suggestion of putting a beefier MOSFET in a Darlington configuration because I had one from a 3D printer hotbed on hand. I think it's this one but I wasn't able to find a good datasheet for it anywhere and the pins on the output side are a little confusing.

12-24V 30A MOSFET

I haven't been able to get the actuator to activate since I put it in the circuit, so it's very possible I wired it wrong. Here is a diagram with the current circuit including the new MOSFET on top, and the previous circuit on the bottom to compare it to. I believe the middle two pins of the new MOSFET are connected (which I marked with a dotted line on the diagram so I could visualize it better), but I can't confirm because I can't find a good data sheet for the internal wiring.

enter image description here

  • 5
    \$\begingroup\$ Please edit your question and use the built-in schematic tool to add a drawing of your setup. Links to datasheets for your devices would also help. \$\endgroup\$ Jul 14, 2022 at 21:08
  • 3
    \$\begingroup\$ a signal wire should not present a load. you should use a mosfet driver and a mosfet capable of handling 50A if your'e using PWM. a fet driver will take your 3.3v input and can drive huge fets with low loss. \$\endgroup\$
    – dandavis
    Jul 14, 2022 at 21:08
  • \$\begingroup\$ It looks like the D4184 module is only rated for 10 amps, and may not be suitable for PWM of an inductive load, especially at high frequency. Here is a page that shows the schematic of the module as well as specifications: protosupplies.com/product/d4184-mosfet-control-module \$\endgroup\$
    – PStechPaul
    Jul 14, 2022 at 21:37
  • 1
    \$\begingroup\$ Do you have a data sheet of the actuator? \$\endgroup\$
    – Jens
    Jul 14, 2022 at 23:56
  • \$\begingroup\$ "the high current feeds through the D4184 and fries it"- sounds like you have it wired up wrong. Please show us the routing of power and ground wires between the power supply, actuator and D4184. \$\endgroup\$ Jul 15, 2022 at 10:05

2 Answers 2


Maybe you could use a darlington style setup with two mosfets. The second mosfet could handle the high current and the first one can handle the the second with a minimal output of the esp32.

  • \$\begingroup\$ Thank you for the suggestion! I was able to find a 30A MOSFET that's normally used for a 3d printer heated bed, and hooked it up between the load and the D4184 in what I thought was the right configuration, however, I'm unable to get any response from the actuator now when I turn on the signal and I'm unsure why. I'll edit my post with updated wiring diagrams. \$\endgroup\$
    – Ursius
    Jul 21, 2022 at 17:10

This likely needs a Motor Electronic speed controller (ESC) that handles 12V with low logic levels and more than 30A so you are not operating at maximum temperature.

These should be class E FET full-bridge amplifiers working as an ESC. You need a full bridge to change directions with a 2 wire DC motor.

The user interface may have different options.

  • \$\begingroup\$ There are many PWM DC motor speed controls rated for 30 to 60 amps, for about $20, on eBay and Amazon. Interfacing it to the OP's ESP32 may be a challenge, and probably deserves its own Q&A. \$\endgroup\$
    – PStechPaul
    Jul 15, 2022 at 3:03

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