Controling a jt-180A water pump

Hello everyone,

I just bought a waterpump for my project but I dont know if it can be controlled and how to control it. The jt-180A waterpump has 3 wires: red + black - and white (dx.com and alibabba suggested it is a speedline). I couldn't find any datasheet or other examples about this waterpump so i searched on google for a 3 wired fan and found this link http://www.instructables.com/answers/Using-a-3-wire-fan-with-Arduino/. Because of this link i tried to control the pump with analagWrite on the analog pin and the pwm pin but with no succes at all. After a couple of hours I gave up to ask you if it is even possible and how it is to be done. I ordered a relais already in case the pump can not be controled and it has te be switched on and off.

To summerize my 2 questions:

Can i control my waterpump with the white wire just like the yellow wire on a 3 wired fan?
If the waterpump can be controlled, what code can i use and with what pin on my uno do i have to connect it?

Any suggestions are very welcome.

Greetz,
Pieter

According to the description of this brushless pump on ebay, the white wire reports the speed (i.e. it is a tachometer lead).

There must be two connections to the tachometer, and I would bet on the black lead as common. Look for pulses on the white/black pair.

You may be able to control the speed by varying the voltage on the red and black motor power leads.

spiedey:
Can i control my waterpump with the white wire just like the yellow wire on a 3 wired fan?

You can't control a 3-wire computer fan (or pump). Only 4-wire fans can be speed controlled without additional hardware. The third (yellow or white) wire is to see if the fan/pump is still running, and at what speed.

If you want speed control, there are several options.

  1. Supply the pump with 12volt, and switch/regulate/PWM the ground/black wire with an N-channel logic fet or NPN transistor. Downside of that is that you can't use the speed sensor.

  2. Use high-side switching with a P-channel fet or PNP transistor. You need a second small transistor as level converter.
    Leo..

You have to push atleast 10v to get it started, then it can run as low as 3.5v. It gives off a less than 1 volt signal from the speed sensor.

Benzapprentice:
It gives off a less than 1 volt signal from the speed sensor.

The tach pin is open collector.
A pull up resistor (to 5volt) is needed.
That can be the internal pull up resistor of an Arduino pin.
Then you have a 5volt peak signal on the tach line.
Tach can only be used if ground of the pump/fan stays connected to ground, and power is controlled high-side.
Leo..

So rude i never got back at you!

Thanks for the suggestions and i will try them out. I had to quit my hobby with the arduino but i am back at it.