How to control a 12v light from car battery?

Hi all,

I've attached my example that I made using fritzing. First, pretend that the 9v battery is actually 12 volts and second, the small LED is actually an actual light that expects power coming from a light.

Third, my MOSFET is this item [ https://www.amazon.com/gp/product/B07MW1N4Q5/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1 ].

The problem that I'm having is that when I try to press on the FSR (and I can see this happen in the serial output that this is working), when a specific threshold is crossed the light does not turn on/off as what I expect it to do. Instead, it turns on about ~15 seconds later... Also, when I press the FSR even harder, the light should turn on continuously, but that also does not happen.

My code on the Arduino works, with the above mentioned MOSFET when I use an actual LED (the power for it comes from the Arduino itself). This leads me to the conclusion that the problem is the MOSFET.

But, my question is this, which MOSFET or some other component is best for when you need to easily and instantly control the flow of 12 volt electricity? I've read online that one needs a MOSFET, did I pick the wrong one?

code ?

Would this be a better MOSFET?

Is that a logic level MOSFET ?

I have used IRLZ44N in the past, and I understand that the L in its name indicates that it is designed to operate at logic levels, but I am by no means an electronics expert

The IRFZ44N is not logic level, won't work at 5V.
The IRLZ44N is logic level, so can work at 5V, in fact as low as 4V.

Completely different parts.

I think there are a lot of unscrupulous people dumping IRFZ44N's relying on the partnumber
similarity.

BTW its dead dodgy buying semiconductors from random suppliers on Amazon, eBay, etc, most
are fakes these days.

Find an approved Arduino stockist or one of the big electronics suppliers that have reputations
to maintain for genuine semiconductors.

You don't have a complete circuit between the MOSFET and the Uno.

You don't have a complete circuit between the MOSFET and the Uno.

(missing a common GND)

raschemmel:
code ?

Does my MOSFET make sense or did I select a wrong one?

First, go back and read some of what was posted. Just post the part number off the MOSFET you have. As mentioned if it an IRFZ44 or similar it won't work. You want a Logic Level MOSFET like the IRLZ44 or a FQP30N06L and both are N Channel so you would low side switch your load. At this point we still have no idea what actual part number MOSFET you have. Just read what is on the MOSFET.

Ron

Until you connect the gnds all bets are off
Then it's a matter of verifying the non logiclevel mosfet is the problem. If you remove the gate from the arduino and connect it to Vcc and the AZGND you can verify the mosfet is the problem. If it doesn't work then youneed to change the mosfet.

Ron_Blain:
First, go back and read some of what was posted. Just post the part number off the MOSFET you have. As mentioned if it an IRFZ44 or similar it won't work. You want a Logic Level MOSFET like the IRLZ44 or a FQP30N06L and both are N Channel so you would low side switch your load. At this point we still have no idea what actual part number MOSFET you have. Just read what is on the MOSFET.

Ron

It is definitely an IRFZ44N. I clearly need a different component.
By the way, what are the differences between an IRFZ44N and IRLZ44? If the latter permits current to flow if one of the pins gets an input, then how does the former function? Does it need a higher voltage in order to permit the flow of current?

Fix the wiring error (connect 12V GND to Arduino GND) and try it, the IRFZ44 may work if the unknown light current is low enough. Carefully pinch it to see if it's getting too hot, if you can hold it for 10 seconds, prob'ly OK.

12vandhigherprojects:
By the way, what are the differences between an IRFZ44N and IRLZ44?

An IRLZ44 is designed to work with logic level voltages (note the L for logic in the part number), that means it will turn on fully with 5V source to gate voltage. An IRFZ44N requires more than 5V to turn on fully, so will probably get hot and waste power and quite possibly go up in smoke if you try to control it with 5V

JCA34F:
Fix the wiring error (connect 12V GND to Arduino GND) and try it, the IRFZ44 may work if the unknown light current is low enough. Carefully pinch it to see if it's getting too hot, if you can hold it for 10 seconds, prob'ly OK.

Would connecting 12V GND to my Arduino GND be a good idea? Won't it fry the Arduino?

12vandhigherprojects:
Would connecting 12V GND to my Arduino GND be a good idea? Won't it fry the Arduino?

More than good, essential. No, it won't fry the Arduino. Read the link Perry posted to find out why.

PaulRB:
More than good, essential. No, it won't fry the Arduino. Read the link Perry posted to find out why.

Ok, so the ground going to the Arduino should also be linked to my car (this is where I'm testing my 12V light). I can do that.

Yes, you need a common ground.

Ron

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.