Power Arduino Below DC Jack?

Other Hardware General Electronics
1

I have a 9v adapter that I hooked up to negative and positive wires to power my Arduino with.

But, I heard that powering through the VIN pin bypasses the regulator and could fry my board.

If I solder the negative and positive wires of my adapter to the correct pins UNDERNEATH the DC Jack, will the power I send go through the regulator?\

Thanks,
Nathan

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2

Vin only bypasses a series reverse protection diode (D1), not the regulator (UNO).

Connect your supply positive to Vin.

FYI
See top right hand corner in this schematic for the: jack, D1 and Vin connections.

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3

nathan_ngu:
I have a 9v adapter that I hooked up to negative and positive wires to power my Arduino with.

But, I heard that powering through the VIN pin bypasses the regulator and could fry my board.

If I solder the negative and positive wires of my adapter to the correct pins UNDERNEATH the DC Jack, will the power I send go through the regulator?\

Thanks,
Nathan

I think what you may have heard was that 'powering your Arduino through the 5V pin bypasses the regulator, and could fry your board.' The VIN pin is there for exactly the purpose of powering your board with a 6 to 12 volt* supply.

Larry posted the schematic that explains how it's all hooked up on the board.

  • actually up to 20 volts, but then it'll get hot.
4

ChrisTenone:

  • actually up to 20 volts, but then it'll get hot.

Some Arduinos (clones) have 16volt electrolytic caps.
With 20volt on V-in it could get hot AND noisy :slight_smile:
Leo..

5

ChrisTenone:
I think what you may have heard was that 'powering your Arduino through the 5V pin bypasses the regulator, and could fry your board.'

Which is also total nonsense. As long as you do not exceed 5 V (5.5 perhaps) or get the polarity wrong, you are not going to damage the Arduino (UNO/ Nano/ Pro Mini) in any way whatsoever.

6

The issue is backfeeding the voltage regulator - whether this is safe or not depends on the
voltage regulator chip itself, and whether there's a diode inline/across it. Different Arduinos and
different versions of Arduinos may behave differently in this regard, and it matters if some
load is connected to Vin or not.

Anyway if you have 9V, you aren't going to connect it to the 5V pin anyway :slight_smile:

7

Paul__B:
Which is also total nonsense. As long as you do not exceed 5 V (5.5 perhaps) or get the polarity wrong, you are not going to damage the Arduino (UNO/ Nano/ Pro Mini) in any way whatsoever.

What you say is true Paul, I power from the 5 volt pin all the time. But the OP was talking about powering it with 9 volts. 9 volts into the 5 volt pin will damage it I believe. His confusion was was with the VIN pin. You can put 9 volts into the VIN pin quite safely.