Need advice

Hello everyone,
this is my first Arduino project (which I later move on the digispark microcontroller). The electrical network simply has to run a DC motor (12-24 volt). The other components are:
-Transistor IRF 520
-Diode
-Digispark USB
-DC adapter which provides adjustable output (15-24 Volt)
-Resistor 10k ohm
The project works, but I'm not sure about the stability.
Do you have any advice?
Thank you.

The project works.

Good, well done, have some Karma.

I'm not sure about the stability.

I've no idea what you are not sure about. If it works, it works. What do you mean by stability and what is it about stability you are not sure about?

It might help if you take a moment to read General guidance And How to use this forum

Image from Original Post so we don't have to download it. See this Simple Image Posting Guide

...R

Fritizing diagrams are much too easy to misunderstand and the pin labels are unreadable.

Just make a simple pencil drawing with everything clearly labelled and post a photo of the drawing.

...R

What do you mean by stability and what is it about stability you are not sure about

I mean It works but I don't know if it can be prone to overheating; I added the components quite randomly drawing from different tutorial

MicheleT99: I mean It works but I don't know if it can be prone to overheating;

I don't know why you said 'stability' when you meant 'overheating'.

I don't know. Does it get hot?

I can smell a bit of burning stink. I want to be sure It won't break after a few times

MicheleT99:
I can smell a bit of burning stink. I want to be sure It won’t break after a few times

What is the size of your motor, watts, volts, amps?
Tom… :slight_smile:

MicheleT99: I can smell a bit of burning stink.

Pffft... long as the smoke didn't get out ;)

I can smell a bit of burning stink. I want to be sure It won't break after a few times

If the motor is being operated at or below its rated voltage and if it is not overloaded or stalled then it should be OK. However, it might be a cheap, poor quality motor or it might be overloaded, but I don't think we can know that, we don't have the motor to look at.

This is the motor I purchase: Motore 775 DC 12V-24V 10000 RPM Motor

I link the Amazon ref. https://www.amazon.it/gp/product/B07JLGJSHS/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

My point is: if I supply 15 Volt to the digispark VIN pin (which, from the documentations "takes 7-12v") is it a problem?

Thanks again for helping me

MicheleT99: if I supply 15 Volt to the digispark VIN pin (which, from the documentations "takes 7-12v") is it a problem?

If I had experience with that actual configuration, and had run it for a year at 15V with no problems, I still would never say to anyone else, "sure, run it outside the maker's specs." I doubt if anyone would give such advice, regardless of their personal experience.

So, Is it better to use a resistor?

Hi, These appear to be the specs.

775 Motor DC 12V 10000rpm Motor Double Ball Bearings 150W Large Torque High Power Motor

Specification: Model 775 Rated voltage DC 12V (12-24V) No load current 1.05A No load speed 12V 10000rpm Power 150W Shaft diameter 5mm Shaft length 17mm Body length 67mm Front steps diameter 17.5 mm Former high level 4.5 mm Body diameter 42 mm Motor Overall Length 98 mm Diagonal installation pitch 29mm Mounting hole size M4 Mounting hole 2 Torque 3kg.cm

Features: Starting current needs to above 10A. Double ball bearings, high speed, large torque, low noise. Built-in cooling fan. Durable and long service life.

Package Included: 1 x 775 Motor

If the no load current is 1.5A, then the protoboard connections and strips may be protesting. The starting current is a bit startling too. :o The IRF520 is not logic level, so may have some volt drop at the higher drain current,

Tom.... :)

Thanks Tom, what do you advise to make everything works properly?

for most electronics, getting new parts to replace things that burn out is the easy and cheap way. SparkFun used to have a magic-smoke refil kit. alas, Sparkfun discontinued sales of the Magic Smoke Refil Kit

I did some research to see if I could replicate it. The crystalline structure of the silicon that makes up the chips seem to crystallize in a tetrahedron form. The Angular lattice of the silicone vaporizes, but the structure remains partially intact. By a rather complicated osmosis process, it might be able to be replenished. The best I could figure is that it would be a process of this rather scientific sounding procedure:

Tetra-Osmosis Tetrahedron Angular Lattice Binary Sedimentation

The acronym does not sound quite as scientific.

MicheleT99: I can smell a bit of burning stink. I want to be sure It won't break after a few times

during the manufacturing process, all metal parts get a thin layer of oil. it is common for things to heat normally, but to have the oil burn off. there is a rule of thumb about motor heat. if you can leave your hand on it for long periods, it is not over heating if you can rest your hand on it for a count of 20 wihtouot pain, you are not over heating if you pull your hand away under 5 seconds, in pain, it is getting hot, need to check the data sheet for normal / maximum expected termperatures, need to check the voltage being supplied, etc if you hear your skin sizzle when you touch, turn off the power and check everything. if it glows red, order a new one. of course there are exceptions, but the voltage to the coil is the key. using the correct voltage to the coil will keep the coil in the warn-not too hot range. if in doubt, lower the motor voltage to a point where it no longer works as expected, then raise the voltage by 20-50% and see if the problems remain. There are times where the motor is not as large as needed to be and the load is too great and a larger motor is needed.

I supply 15 Volt to the digispark VIN pin (which, from the documentations "takes 7-12v") is it a problem?

You can't be sure it won't be. Does anything on the board get hot*? If it does, then that's a problem. Better use a buck converter to 5V and supply the board with that. However, even if nothing is hot, if you are outside the maximum voltage specification you can assume that sooner or later something will die.

*Rule of thumb for 'hot'. If you can touch it with your finger and it doesn't hurt then it's not too hot. If you can't keep your finger on it then it's too hot.

I would think the backward connected diode is really getting hot. :)