• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Problem in 5v pump

KiroloesAmir

New Member
I connected the pump to tip122 darlington transistor to control it via serial port. but the pump doesn't work. instead , it makes sound. how can i make the pump work the circuit of the tip122 :
Screenshot 2021-01-07 023405.jpg
the circuit of the power supply :
Screenshot 2021-01-07 030509.jpg


the features of the pump :


Mini Water Pump, Northbear Ultra-quiet Mini DC 3-6V 120L/H Brushless Motor Submersible Water Pump

Material: plastic+electronic components
DC Voltage: 2.5-6V
Flow rate: 80-120L/H
Power: 0.4-1.5W
Maximum lift: 40-110cm
Outside diameter of water outlet: 7.5mm
Inside diameter of water outlet: 4.7mm
Diameter:Approx. 24mm
Length:Approx. 45mm
Height:Approx. 33mm
Material:engineering plastic
Driving mode: brushless dc design, magnetic driving
Continuous working life of 500 hours


photo of the pump :

mini_pump_1-400x300.jpeg
 

audioguru

Well-Known Member
Most Helpful Member
A brushless motor usually uses 3 wires and is driven by a brushless motor controller called an ESC (electronic speed controller.
 

ChrisP58

Well-Known Member
Most Helpful Member
I connected the pump to tip122 darlington transistor to control it via serial port. but the pump doesn't work. instead , it makes sound. how can i make the pump work the circuit of the tip122 :

. . . .
The signal from a serial port is not a sustained, continuous on/off. It is a series of pulses representing the data that is being transmitted. And when the data ends, the signal line reverts back to it's original state. That could explain why it's making a sound instead of running. It's actually being rapidly turned on and off.

You need a signal that you can set to be a static high or low.
 
Last edited:

gophert

Well-Known Member
Most Helpful Member
What power supply are you using? The current draw from the water pump may be causing a brownout and causing the microcontroller to keep restarting.

try connecting your battery directly to the pump motor to make sure the motor works.

Some of those cheap pumps have some binding issues because of poorly cut gears or burrs from poor injection moldings on the magnetically coupled pump.
 

Neilf

New Member
Put a diode in series with the transistor gate and a capacitor down to 0v,you would be better with a mosfet.
 

audioguru

Well-Known Member
Most Helpful Member
what is the relationship between the brushless motor and 5v water pump has two wires only ?
Wikipedia says, "Brushless DC electric motor - Wikipedia
A typical controller contains three bidirectional outputs (i.e., frequency-controlled three-phase output), which are controlled by a logic circuit."
They show a two-phase brushless motor in a fan that might be like your motor.
Maybe the manufacturer of your pump lied and it is actually a brushed motor which explains why its lifetime is only 500 hours (21 days).
 

Reloadron

Well-Known Member
Most Helpful Member
Where did this circuit come from? There are a pair of 2200 uF caps across the motor so you have 4400 uF across the motor, why? Typically with a brush type motor which is what I see it as you might put a .1 uF cap across the motor to reduce noise. What purpose does D4 have? Other than dropping about 0.7 volts I do not get what it does? If it is supposed to be a flyback diode it would go across the motor terminals with the cathode side going to + (positive).

As to brush or brushless my best guess if it is brushless it would be like a two wire BLDC fan motor. The type found in home computers for an example.

You mention control via the serial port and that makes no sense. Connected to the serial port how? What pin and what software?

Ron
 

Latest threads

EE World Online Articles

Loading
Top