Powering Arduino AND a L298N/Stepper motor

Hello,

I'm trying to power my arduino and L298N from a single supply.

The L298N board has a 5v out which others have said CAN be used to power the arduino. However, i've found that the supply I'm using (12v 2A DC into the L298N) doesn't supply enough current to the arduino to keep it alive when the stepper motor is running. I also have an LCD screen running from the arduino along with a strain guage, the LCD screen is dim (compared to when I power the arduino via USB).

I realise i may need to buy a different power supply. My electronics knowledge is not strong, how can I power both boards from the same power supply without overloading either?

Many thanks,

Luke

Get a power supply that can deliver the current you require. No other way.

I think if the PSU had a larger current, more would be drawn by the motor driver board (which i dont want be cause it already gets too hot).

How can I ensure that enough of the current is drawn by the arduino and it's not all hogged by the driver board?

Thanks,

Luke

That is just plane wrong thinking. If your motor is drawing too much current then you need either a lower voltage or a better designed motor driver.

That question just screams that you know nothing about the way electricity works.

Supply the correct voltage and the current draw will be correct.

Thanks for your responses Grumpy-Mike.

As I say, my electronics knowledge is not strong. Perhaps I phrased my question poorly.

In more general terms, If I want to supply several circuits with one power supply, how can I ensure that the voltages (and thus currents, based on the corresponding resistances ;)) to each circuit are, and stay appropriate? Especially seeing as something like the motor driver will not draw a constant current.

Even if i've got the complete wrong end of the stick here, some clarification would be golden.

Many thanks,

Luke

If I want to supply several circuits with one power supply, how can I ensure that the voltages (and thus currents, based on the corresponding resistances ;)) to each circuit are, and stay appropriate?

You have no need to do anything. Providing the things you are going to power all expect the same voltage they will sort themselves out and only take the current that they individually need. Your power supply just needs to output a constant voltage independently from the current being drawn. It will / should do this up to the rating rating of the supply.

If you exceed the current rating of the supply then the voltage will drop and it is a sign that your power supply is not big enough ( current rating ) for the job you are asking it to do and you will need a better one for your project.

Especially seeing as something like the motor driver will not draw a constant current.

A motor will take the current it needs. This need will depend on the mechanical load the current is under. Your power supply should be capable of supplying the current up to the maximum load which in the case of a motor could be the stall load, given by the motor's coil resistance and drive voltage.

It is fine, in fact a good thing, if your power supply never has to delver its full current rating. In fact it is best to run them at 80% or under.