Hey everyone, I'll use a 12V/2A solenoid controlled by the arduino UNO. Got a 12V/5A switching dc power supply as seen in the following pic.
The problem is that not all the voltage (12V) goes to the solenoid (not even 11V).
First time I used a BJT transistor and only 7.5 V the solenoid got through. A proffesor of mine suggested to use a mosfet instead a BJT, so I found the IRLZ44n (a mosfet used for arduino mainly) and now the arduino got 8V/1.1A. It's not enough, I need at least 10V and 1.5A.
I even connected 5 4700uF capacitors in parallel in the power supply terminals but I think it's worse, the solenoid voltage is lower (6.86V)
Does anyone knows what can I do? at this point I am kinda lost and a little frustated
All the voltage is going there, but where else is it going…? Heat, noise etc
Solenoid specs, and don’t forget a beefy snubber diode when it is working.
I'm using the ARDUINO UNO. So do I put in series the 10k and 150 ohms resistor? sorry if I didn't get it.
My circuit is kinda messy, do you want to take a look anyway?
Yep the schematic says FQP30N but it's just an alternative. He suggested to use either FQP30N or IRLZ44n (which I used).
And I connected the Arduino UNO to my pc usb. It gives me 5v, doesn't it? I got 5v from the D8 output every time I send a high pulse to the gate (read with my multimeter).
You need to measure voltages around the circuit to see where the voltage is being lost. As shown in this fig connect the negative lead of your meter directly to the 0V output of the 12V psu and poke around points 1,2,3,4,5,6,7 etc with D8 LOW, and again with D8 HIGH
Hi beverly! dont even assume both ends of a wire will be at the same potential, a thin wire can lose a lot of voltage if the current is high (that means more than a few milliamps)
Yes please. I am not looking for a tidy circuit, I am looking for things that could cause a voltage drop. Things that don’t show up on a schematic. Like if you have heavy current flowing through a solderless bread board, you should limit bread boards to less that 1A. They are not designed for heavy current. There is other stuff too, I will know if I see it.
But with those resistors being the wrong way round you will not get the same voltage on the gate.
I got 4.9V into the Gate pin from the arduino (measured with multimeter) and 8.4V in the terminals of the solenoid and 1.3A. Here is my circuit in my bred board
Easy to see where voltage drop is coming from, trying to pull 2 Amps through skinny wires and "iffy" breadboard connections. What is the voltage from power supply + to - when you are reading 8.4V on the solenoid?
