Mosfet recommendation?

Does anyone know of a reliable MOSFET module that can handle 12V and 10A and I can purchase on Amazon?

I bought a FOTEK SSR-25 DD which is supposed to handle 5-60 volts and up to 25A, but as soon as I try to pulse more than 1A at 50hz, it stops working and I have to reduce the load.

I was originally using a standard DC relay module, but anything over 20hz and the latch would stick. Started looking into a MOSFET. Bought the FOTEK since it handles a 3-32v control and a 5-60v load at 25 amps.

I'm pulsing the ground on a 12v valve using D13 on an arduino nano. One valve at a time works perfect as they only draw a 1A load. Anymore than 1 valve and they stop working completely. If I switch back to a plain DC relay module, I can pulse 20 of them but not at more than 20hz.

The SSR can only switch AC loads. It relies on the AC voltage passing through zero for the relay to switch off. If you are switching DC or trying to switch faster than the AC line frequency then this is the wrong part to use.

The last paragraph sounds complex. Can you draw the circuit schematic?

Amazon is not the place I go to to find MOSFETS. But I'm sure they have suitable ones, probably in packs of 10. Just pick something that has a datasheet.

The way to read a MOSFET datasheet is to skip past all the "marketing claims" and go to the first chart, usually top-left on the second page. Look at what voltages they put on the lines on the chart. Find 5V or 4.5V. If you can't, then don't buy that MOSFET. If the 5V line is significantly lower than the 10V line then don't buy that MOSFET.

Does anyone know of a reliable MOSFET module that can handle 12V and 10A and I can purchase on Amazon?

Very difficult to do because the vast majority of parts on Amazon lack datasheets and published specifications.

You cannot use mechanical relays at any duty cycle higher than cycles per minute without them self destructing in short order. Typically, the smaller they are the faster they can switch but trying to switch at even 5-10Hz is unrealistic for a mechanical device.

Your switching problems sound more like a power supply issue than anything else. Please provide details on the actual loads you’re trying to control, the final desired switching speed and and the power supply being used. A generic spec of 12 volts at 10 amps means very little with respect to properly selecting a switching device.

The power supply is a 12v 40A supply that plugs into a wall outlet. I've used it to power several several electric motors at 35A and it works perfect.

All I'm trying to do now is pulse a 12v signal.
A cheap breakout relay works PERFECT as long as the frequency doesn't get too fast.

Now I'm in a situation where I need faster.

The valve is a 12v valve used in a cooling system. It gets constant 12v power, and I've been using a mechanical relay to pulse the ground. Current draw on the valve is 1 amp.

I want to be able to pulse up to 10A at a speed faster than a mechanical relay can do. I just need a recommendation on what to use. I've tested dozens of mechanical relays and the latches always stick.

I've tried 3 types of MOSFETS now, all with zero success. The FOTEK one will pulse a single valve. Add another valve or a larger valve and it gives up. The mosfet modules I bought that are made for 3D printer hotbed controls don't seem to work either.

Can someone give me a simple recommendation for something that operates like a mechanical relay, only faster, so I can control it via arduino PWM?

You need to understand that saying you have a 12 volt valve tells us very little about what you’re trying to control. The more you just keep asking for a recommended relay, the more this just becomes an x-y problem

Is this device designed to be rapidly switched on and off?

Do you have a diode across the coil of this device you’re trying to control?

What’s the inrush current when switched on?

What’s the brand of power supply? A Chinese no name special? Have you load tested it with a PWM load?

Do you have an oscilloscope? That will provide a much deeper understanding of what’s wrong and until you understand why the Fotek relay doesn’t work, you’re not going to solve the problem by guessing.

The fact the the mechanical relay contacts weld in short order tell you there is something going on with the load that you don’t understand. Why continue to change relays in hope of finding one that works? Evaluate what’s in front of you and learn from it. Only then can you move to the next phase of the project.

The valve operates at up to 1khz in their original environment with nothing more than an unregulated 12v supply and a pulsed ground.

The power supply is irrelevant. I've tried the 12v power block that these valves were designed to use and I get no results either.

The mechanical relays work fine. When I increase speed and amperage, they begin to latch. Not uncommon. They latch because I'm trying to switch up to 10 Amps at 20-50 hz. Cheap relays latch at 20. More expensive ones can sometimes do 50.

The problem isn't in the valve, power supply, programming, or wiring. It's the hardware being uses to switch the load. I just need something more robust.

Well, the FQP30N06L or RFP30N06LE can certainly switch a 1 amp load at 12 volts at Arduino default PWM rates with no issues whatsoever. Proper hookup is below, the diode is not optional.

That mosfet works fine. The max amperage is a little low. If I add another valve, it does the exact same thing that the FOTEK one does and stops cycling all together from lack of current.

I've bought several mosfet modules from amazon and Ebay. So far, none of them work as planned, but I'm assuming that I'm just wiring them wrong.

Heat Bed Mosfet, MACTISICAL 2 Pack 3D Printer Heat Bed Power Module 3D Printer Board Expansion Board MOS Tube High Current Load Module

DROK 200203 DC 5-36V 400W Dual Large Power MOS Transistor Driving Module, FET Trigger Switch Board, 0-20KHz PWM Electronic Switch Control, DC Motor Speed Controller DROK 200203 DC 5-36V 400W Dual Large Power MOS Transistor Driving Module, FET Trigger Switch Board, 0-20KHz PWM Electronic Switch Control, DC Motor Speed Controller: Industrial & Scientific

On both of them, I'm supplying 12v power/ground, and then running power/ground from the valves to the load side. For the control, I'm running ground to the arduino ground pin, and then doing PWM off of pin D13 on the nano.

Well, pin 13 is a lousy choice because there is an LED already hanging on there sucking up current. Any other PWM pin is a better choice.

As a guess, you could be running out of drive current and you need to stop driving the devices in parallel if in fact that’s what you’re doing. With one mosfet, try replacing the coil with a 50 ohm resistor, that will give you 100ma of drive current and try driving multiple gates from that drain to resistor connection point. Dunno. A scope would be a game changer and eliminate the guessing.

You could also prove the theory by using the six individual PWM pins, driving one load with each pin. See how that works.

Would you please explain in detail just what you’re trying to do? You keep repeating switching 12 volts at 10 amps.

Is that 10 x 1 amp solenoids?

Are you attempting driving multiple mosfets from one Arduino pin?

One solenoid per mosfet?

Solenoids in parallel or one solenoid per mosfet?

"and I can purchase on Amazon" Why not search at You can filter for that current and voltage much easier, find a package you can work with easily, and also look for a Low Rds (like 0.01 ohm or lower - AOD51x for example) so it will run nice & cool.

Pin 13 is NOT a PWM pin, could we see the program that is switching pin 13 at 50Hz? Also, a link to that valve.

"pin 13 is a lousy choice because there is an LED already hanging on there sucking up current."

On an Uno, pin 13 drives LM358, an op amp with very low current input, the LM358 then drives the LED. The LED takes no IO pin current.