DHT 11 burnt with external power supply

Hi guys,

I'm using Arduino uno with a display and DHT11 sensor. With the USB power supply it works all good but with external power supply (ACDC adapter 9 V / 1 A) the sensor was burnt.

This was cause the input corrent is too high?

How can I solve this problem?

Thanks

The DHT11 is maximum 5.5V.

Please explain what you did, and how it was connected.
Did you use the Arduino 5V pin for the DHT11, and hopefully not the Vin pin ?
Did you use the external power supply only for the Arduino, not directy to the DHT11 I assume ?

I use the 5V pin to connect the DHT11 and yes, I use external power supply only for arduino

sensor: http://4.bp.blogspot.com/-PCM-KSjQz3M/U4uPrGUiCzI/AAAAAAAADS0/e2Hck3iQVww/s1600/DHT11_Pins-300x274.png

I did the connections below:

1 --> 5V pin
2 --> pin 8
3 --> none
4 --> gnd

It should not be possible to damage the DHT11 sensor. As far as I can tell, you did everything right.
Does your board have a fault ? Can you measure the 5V pin ?

Peter_n:
It should not be possible to damage the DHT11 sensor. As far as I can tell, you did everything right.
Does your board have a fault ? Can you measure the 5V pin ?

I assume that my board works properly, because with other projects i don't have any problems.

However I'll try to measure the 5V pin and then I'll tell u the result

thx :wink:

as the voltage is alright, the current would not lead to any damage.

Perhaps you accidently touched the DHT11 with a higher voltage, or the DHT11 just broke down and using external voltage was just coincidentally.
Buy a new one and you will be okay 8)

post a photo of your circuit. The DH1-11 Vcc is pin-1, and GND is pin-4. If you plugged the sensor in the other way it would be connected backwards and possibly damage it. What do you base your conclusion that the sensor is "burnt" ? Did you see a puff of smoke at some point ? How do you know it is damaged ?