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Topic: transistor usage (Read 1 time) previous topic - next topic

gaston80

Hello World!

First of all, I am a newbee in electronics...

I would like to manage a water pump (max 6V, 30mA) with an arduino uno. The pump works well if I connect it on the 5V pin and the ground.  To manage it, I have a NPN S9013 transistor. My schema is :
- arduino 5V connected to the collector
- arduino pin 8 connected to the base through a 1kOhm resistor
- the emitter connected to - of the pump
- the + of the pump connected to the GND pin of the arduino

The arduino is power by the USB port.

The arduino code is as simple as:

void setup(){
  pinMode(8,OUTPUT);
  digitalWrite(8,LOW);
}


void loop(){
  digitalWrite(8,HIGH);
  delay(2000);
  digitalWrite(8,LOW);
  delay(2000);
}


It doesn't work and I don't understand why. Can anyone help me?

groundFungus

The transistor is in the wrong place.  It should be pump + to 6V, pump - to collector, emitter to ground.  The 1K base resistor is fine.  I find it hard to believe that the pump only draws 30mA.  Do you have a datasheet or a photo of the pump nameplate?

JimboZA


The transistor is in the wrong place.  It should be pump + to 6V, pump - to collector, emitter to ground.  The 1K base resistor is fine.


Or to put it pictorially, see attached. (My pic shows pin 7, but whatever....)
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

gaston80

First of all, thank you for your answers!!!!!!

It is a really cheap one: http://www.ebay.com/itm/Peristaltic-dosing-Head-6V-DC-Dosing-pump-For-Aquarium-Lab-Analytical-water-DIY/111343325641?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=23490&meid=60d22153fcd24cd197779d1f7bc2a00f&pid=100005&prg=10073&rk=3&rkt=6&sd=201087635665&rt=nc

I tried your solution without any success. I do not understand why did you put this diode.

I also tried another thing, with a 9V battery.

9V battery + connected to the arduino 5V and to the + of the pump
Pump - connected to the collector
emitter connected to the arduino GND and to the battery -

The pump works but it does not stop each 2 seconds... it should be because of the missing diode or is my transistor broken?

TomGeorge

Hi, try +5V to pump +, collector to pump -, emitter to gnd, leave base connecton open, if motor runs then transistor is u/s.
The diode is to prevent damage to the transistor and the arduino from current and voltage spikes fro the DC motor.

Tom..... :)

Do not put 9V on the arduino 5V pin.......
Everything runs on smoke, let the smoke out, it stops running....

JimboZA

And the diode goes "backwards", cathode to +ve supply
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

gaston80

Ok my transistor is OK.

Thank you for your explanation about the diode.

I will not try the 5V supplied with 9V any more, promise.... (I have to leave my computer a bit..)

I think that it should be a loss of power because my pump, in rare situation moves a little bit (<1sec)

gaston80

Thank you guys!

You help me well on my project.

I tried with another type of water pump which is asking 9V. Powering either the arduino and the pump with my battery, my pump works as wanted

Thank you!!!!

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