I am trying to make a motor spin with an Arduino. I am using 4 transistors to make an H-bridge so that I can reverse the direction. When I power the board with a 9v battery the motor just twitches pack and forth in the right direction but will not spin. However, when I plug the motor directly into the battery it works great. What is causing this?
I am using a small 6v motor and IRF540n transistors. I also plan to use a bigger motor (12v, 2amps) and a 12v battery later.
Here is a picture of my circuit
"Here" is a picture... Where is "here"?
9 volt battory is alarming. I assume it's that kind found in fire alarms. They are voltage sources, not power sources.
Wiring diagram for the H-bridge please.
All of us don't have chrystall balls available...
Sorry the image did not work
Your last 2 post don't work either. Take a rest and post Your question according to the first topics like "How to use this forum".
Also, you might want to take into account how much current the breadboard can handle.
themaster928:
I am using a small 6v motor and IRF540n transistors.
That's a wrong approach. If you don't use logic level MOSFETs you need a gate driver for each FET. A driver also is required for the high side switch with p channel MOSFETs.
Have a look at the circuit diagrams of already working H-bridges.
couple of things.
A transistor uses current [as the signal ] to drive the device.
A FET/MOSFET uses voltage.[ as the signal ]
These are totally different devices, but in the same size case [TO92, T220] and used for very similar applications.
As for the 9-volt battery, it will not last very long. As was noted, it us useful when you need voltage, but not a good choice for power. We are talking minutes of life, not days.
The forum has some functions you can find out about in a sticky post HOW TO USE THIS FORUM,
https://forum.arduino.cc/index.php?topic=148850.0
It is located as a sticy post att the top of every forum. It shows some things that are very helpful in how to post. Like photos. Photos have to be jpg and under a specific size. You have to attach them from the drop down under your post, they are not drag and drop.
Please take a minute and hand sketch your layout , take a pic with your cell phone and try to post that. Use PAINT or any drawing program, but then reduce the size to the forum limits.
Back to your question :
What you are describing is an H-Bridge, you have to use 2 P-type that connect to power, then feed the device , and the device is connected to ground.
And you have to use 2 N-type that are connected to the ground side of the device, and then to ground. So, you cannot make an H-Bridge from 4 of the same FET.
We tend to think of a switch as connecting to power, and feeding a device.
For N-type, you connect power to the device and switch the ground line. Takes some getting used to.
It seems you have most of the stuff, just a few changes and you will have it working.
Breadboards are for logic circuitry, not motors. Motor current will burn the breadboard connectors.
Either solder motor connections or use screw connectors.
Try an simple test.
assuming the motor can take 9volts, connect the 9 volt positive to the motor
connected the ground of the motor to the proper pin of your FET
connect the proper pin of your FET to ground
connect the Arduino signal to the proper pin of the FET.
this would allow you to (hopefully) get the motor to spin on command.
it would not reverse, but it would validate that you can get some stuff to work.
as a note, we typically suggest you posts links to things like motors. as was noted, power and breadboards are not something to mix. if your motor is tiny, there may not be any problem.
our goal, and yours, is to have fun, be safe, and get that bits to work !