Why do I keep destroying Arduino Nanos?

Hi everyone, this is my first post so sorry if I don't know what I'm doing.

I'm working on a project where I use a DC Boost Converter to increase the voltage of a 9V battery to around 50V which I want to store in 5 1000uF 50V capacitors in parallel.

These capacitors would charge and then discharge through a solenoid. The charging and discharging is controlled with the Arduino and two N-Channel Mosfets.

The arduino is only connected to the gates of the mosfets and ground so I don't know how it fried my arduino. I've been testing with the boost converter only set to around 10V.

I've added a picture of my breadboard.

Thanks for any help provided!

DenHead12:
Hi everyone, this is my first post so sorry if I don't know what I'm doing.

I'm working on a project where I use a DC Boost Converter to increase the voltage of a 9V battery to around 50V which I want to store in 5 1000uF 50V capacitors in parallel.

These capacitors would charge and then discharge through a solenoid. The charging and discharging is controlled with the Arduino and two N-Channel Mosfets.

The arduino is only connected to the gates of the mosfets and ground so I don't know how it fried my arduino.

I've added a picture of my breadboard.

Thanks for any help provided!

A schematic is much more important than a missing picture.

Paul

DenHead12:
I've added a picture of my breadboard.

Think I have spotted the problem!

Also: Define "fried"?

Hey there just make sure u have ur pin configuration correct, using Vin gor ur 9v batt. also some knock off boards Inland in preticular have a engineering problem. no pin will regulate can handle 7v on all power pins but any more ull fry. they screwed the traces up

let me know what u found tho, and what exact brand of arduino u using

I'm sure you meant to say something, but it certainly was not effective! :roll_eyes:

Paul__B:
Think I have spotted the problem!

Also: Define "fried"?

The arduino no longer connects to my computer and the RX light is on continuously. I've searched it up and it's likely that one of the output or input pins got too high of a voltage and it won't work anymore for anything useful.

I forgot to mention that this happened while testing with the boost converter set to around 10V so I think the breadboard should be able to handle it would it not?

Paul_KD7HB:
A schematic is much more important than a missing picture.

Paul

I just learned how to make one and I posted it! Hopefully it's alright.

The easy-to-see version of OP's added schematic

  1. Resistors are required between a port pin and a MOSFET gate to limit the pin current. 150 Ohms is a suggested minimum.

  2. The wiring for Q2 is wrong. Q1 will allow the capacitors to charge once, but what is Q2's purpose?

  3. How are the capacitors supposed to discharge?

  4. MOSFETs are not logic level. Use logic level MOSFETs with Arduino pins.

The charging and discharging is controlled with the Arduino and two N-Channel Mosfets.

Difficult to see how this would be possible, and the circuit you have posted certainly won't accomplish that task.

I suggest to use a logic level MOSFET to control a high current relay to switch the capacitors between charging source and load. Suggested circuit to control the relay:

Thanks for response and all the information! I'll go through what you've written.

jremington:

  1. Resistors are required between a port pin and a MOSFET gate to limit the pin current. 150 Ohms is a suggested minimum.

  2. The wiring for Q2 is wrong. Q1 will allow the capacitors to charge once, but what is Q2's purpose?

  3. How are the capacitors supposed to discharge?

  4. MOSFETs are not logic level. Use logic level MOSFETs with Arduino pins.Difficult to see how this would be possible, and the circuit you have posted certainly won't accomplish that task.

I suggest to use a logic level MOSFET to control a high current relay to switch the capacitors between charging source and load. Suggested circuit to control the relay:

  1. Perhaps this is why the arduino broke? I didn't realize I needed resistors between the output pins of the arduino and the gate of the mosfet, I'll be sure to add those.

2/3. The idea is that while the button is held the arduino sends a signal to Q1's gate, closing a loop with the power supply and the capacitors, resulting in them being charged. Once charged, the button gets released and the signal gets switched to Q2's gate closing the loop between the capacitors and the load(currently an LED). From what I understand the 12V power supply will do nothing once Q2 is closed and Q1 is open because there is no closed loop for the power supply. The circuit actually did work for a bit before the arduino became unresponsive, probably due to not having resistors between it and the mosfet gates.

  1. The mosfets say they work with arduino which probably makes them logic level? I didn't realize there were even different types.

In regards to your suggested solution, I initially tried using a relay but it was fusing due to the high currents. I did some research and many sources informed me that I could just use the mosfet as a little more difficult to implement high current relay.

Thanks again for the response. Let me know if I have to explain anything better.

MOSFETs don't "say" anything. Did some seller incorrectly claim that IRFP250 is Arduino compatible?

I suspect that Q2 was destroyed by a drain gate short, which let 12V into the Arduino. The design you posted cannot work.

You need to learn how MOSFET switches work -- plenty of study material on line.

jremington:
MOSFETs don't "say" anything. Did some seller incorrectly claim that IRFP250 is Arduino compatible?

I suspect that Q2 was destroyed by a drain gate short, which let 12V into the Arduino. The design you posted cannot work.

Eagle didn't have the mosfet I had, I'm using RFP30N06LE mosfets which the seller said are arduino compatible. I'm fairly new to electronics so I'm learning as I go.

DenHead12:
Eagle didn't have the mosfet I had, I'm using RFP30N06LE mosfets which the seller said are arduino compatible. I'm fairly new to electronics so I'm learning as I go.

You can probably use the Value tool to change the part number shown for the MOSFET (it will tell you there's no editable value, but let you edit it anyway).

This is a perennial frustration on these forums - new users use tools to draw schematics that don't have the parts they're using, so they post diagrams that show part numbers different from what they're using, and then the people trying to help them point out problems with the part shown on the diagram, which is not actually the part being used. If you have to use a library part that doesn't match what you're using, be sure to tell us what part you're actually using.

MOSFETs vary in terms of what voltage needs to be applied to the gate (relative to source) in order to turn the MOSFET completely on. "standard voltage" (no mention of logic level) implies that they need Vgs=10v (for use with a 12v signal, typically) - these won't turn on with an Arduino, "logic level" means they will turn on with Vgs=4.5v (5v logic, less margin of error) - or lower. Always check the datasheet for MOSFETs - they will spec Rds(on) at one or more gate voltages (Vgs); the lowest one with a specified Rds(on) is the lowest voltage you should try to use to turn on the MOSFET. Applying a voltage between that and Vgs(threshold) will result in the MOSFET being sort-of-on, but with much higher drain-to-source resistance than expected, which in turn means that more power (heat) will be dissipated in the MOSFET, which can burn it out. The RFP30N06LE is fine at 5v; it won't work at 3.3v (I recommend the IRF3708 as the "go to" hobby MOSFET, as it works at 3.3v too - though it's a bit more expensive than the RFP30N06).

Some hobbyist-centric vendors lie about what MOSFETs are suitable for use with what logic levels. There are a lot of 4-channel MOSFET boards on ebay that claim they're compatible with Arduino, but which use "standard voltage" MOSFETs (that's what led to my deciding to sell 4-channel MOSFET boards in my Tindie store)

around 50V which I want to store in 5 1000uF 50V capacitors in parallel.

Isn't that a little tight on the tolerances?