Arduino 5V regulator is too hot

I’ve a car proyect with arduino that needs arround 550mah, but the Arduino 5V regulator is too hot, Can be a pololus heat sink the solution?

Best regards.

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What are you powering the Arduino from, 12VDC from the car's DC jacks and plugging that into the Arduino through the barrel connector?

What are you powering that requires 550mA?

If the regulator is getting really hot, I'd get a separate DC/DC converter to provide power instead of getting a heat sink. While the heat sink may help, you still run the risk of the regulator shutting itself down (especially if the inside of your car is really hot on a summer day for example). Not to mention the Arduino uses a linear regulator, whose output voltage will decrease as you draw more current. Here's a switching step-down DC/DC converter that you can give 12V input, and it will provide a steady 5V output for up to 600mA. The 600mA max current is close to your 550mA, so just double check what your actual current draw is.

Not to mention the Arduino uses a linear regulator, whose output voltage will decrease as you draw more current.

Not true. A linear regulator will continue to supply 5V until you go over some limitation. The NCP1117 used on the Arduino Uno is rated at over 1A output. However, with 12V coming in, and 550mA coming out, that is around 3.6W. A lot for such a small package.

I agree with the rest- use an external switch mode regulator. But I would never use a regulator at 90% of its rated current. Use one that is rated for double what the circuit needs.

But - is this going to drive motors? Are you taking stall current into account?

Yes, use a step down DC to DC converter!
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pcdangio:
What are you powering the Arduino from, 12VDC from the car's DC jacks and plugging that into the Arduino through the barrel connector?

Yes.

pcdangio:
What are you powering that requires 550mA?

I'm using the 5V to power a sim908 module for charging the battery, the module need 500mA to fast charging the battery.

pcdangio:
If the regulator is getting really hot, I'd get a separate DC/DC converter to provide power instead of getting a heat sink. While the heat sink may help, you still run the risk of the regulator shutting itself down (especially if the inside of your car is really hot on a summer day for example). Not to mention the Arduino uses a linear regulator, whose output voltage will decrease as you draw more current. Here's a switching step-down DC/DC converter that you can give 12V input, and it will provide a steady 5V output for up to 600mA. The 600mA max current is close to your 550mA, so just double check what your actual current draw is.

Somebody have this circuit scheme?

LarryD:
Yes, use a step down DC to DC converter!
Lots on eBay
here

I’m looking for a DC to DC converter from 12V to 5V scheme.

xload:
I'm looking for a DC to DC converter from 12V to 5V scheme.

pcdangio:

xload:
I'm looking for a DC to DC converter from 12V to 5V scheme.

Pololu - Step-Down Voltage Regulators

A lot of thanks, I will buy one, but i also want to know hoy it works and see the scheme.

but i also want to know how it works and see the schematic

https://www.dimensionengineering.com/info/switching-regulators

NCP1117 only rated for 800mA from 12V:
Vin = 6.5 V to 12 V, Iout = 0 mA to 800 mA: Vout = 5V +/- 0.1V

Can go higher current, but Vout starts to swing more, and Vout - Vin is limited to 5V (so Vin = 10V tops).

The MC34063 is a very easy to find, cheap buck, boost, or inverting switch mode regulator. In fact, I can go to the local dollar store and buy tiny cigarette lighter socket 12V to 5V USB phone charger/adapters for… a dollar each.

The chip uses an internal switching transistor good for 1.5A switching, 750mA output current. An external inductor and shottkey diode and a handful of other parts are needed, but the lighter socket adapters have those already. Chances are, any cigarette lighter socket adapters use the MC34063.

http://www.onsemi.com/pub_link/Collateral/MC34063A-D.PDF

You can check the part values, but I believe they already have current limiting set to 500mA. I’d use that to power the charger, and use a separate regulator to power the Arduino.

I like this calculator for the MC34063 because it allows you to specify an input voltage range. You need to figure it out as the middle of the voltage range, and percent variation.

http://dics.voicecontrol.ro/tutorials/mc34063/