I am new to Electronics so, could someone kindly confirm that the instructions above would apply for my water pump as well? I have no problem with the programming bit, but am worried about frying the arduino or the pump before reaching that state, so any clues would be appreciated.
Features:
Support for positive and negative transfer
High accurateness in flow control
D(1.5-4)mm0.5m silicone tube is included for using
Environmental protection silicone tube for food and medical industry
Simple structure and low maintenance
Specifications:
Voltage: DC 12.0V
Flow Velocity: (6~24)ml/min
Operating Temperature: 0~40 degrees centigrade
Relative Humidity: < 80%
Part List:
1 x D(1.5-4)mm0.5m Silicone Tube
1 x Micro Peristaltic Pump
Good you asked here on this forum, because the circuit used in the instructables is wrong. There should be resistor between the Arduino output pin and the transistor base.
I can't find how much current the pump is. Not even here : http://www.makeblock.cc/micro-peristaltic-pump-dc12-0v/
The 2N2222 can do up to 800mA. I don't know if that is enough for the pump.
You could also use a TIP120 or mosfet instead of the 2N2222.
You really need to know the current demand of the pump (ideally the stall current), which the manufacturer does not seem to provide. I would guess one ampere.
However, at the very least you will need a transistor and a resistor to control the pump, and a separate 12V power supply for the motor. This tutorial offers several possibilities. A motor driver module, preferably from Pololu, is also a possibility.
Beware that the web features some very bad tutorials on Arduino motor control.
Thanks a lot for the answers. I've contacted the electronics shop, who have kindly tested the pump, they are saying that:
We have tested the pump without any liquid but with the tube attached and measured 160mA, we would expect this to be less once there is liquid inside the tube. The thicker the liquid the more resistance the motor will experience and the less the current will become.
denizengin:
We have tested the pump without any liquid but with the tube attached and measured 160mA, we would expect this to be less once there is liquid inside the tube. The thicker the liquid the more resistance the motor will experience and the less the current will become.
Does this sound backwards to anyone else?
Generally the more resistance a motor encounters the GREATER the current it will draw.
The 160mA is not a lot, and it was with the tube, and the quality of the motor is not extremely good, so I expect that the stall current does not go up a lot. Maybe only 50% more. For safety I would say three times the 160mA.
The 2N2222 should be okay. You need a 2N2222 plus base resistor plus diode. However, a TIP120 or mosfet are fine as well.
A mosfet of 60A can be used for a pump of 160mA. That is normal.
