This tutorial is an introduction to ULN2003. We will see the features, applications, pinout, and details of all pins and one example at the end of this guide on ULN2003. It is also used as a relay driver.
PIC Microcontroller 5 Relay Driver circuit using ULN2003 Stepper motor driver using parallel port This is an easy to build stepper motor driver that will allow you to precisely control a unipolar stepper motor through your computer’s parallel port. You could simply add another 28BYJ-48 stepper motor and ULN2003 driver or upgrade to a geared-down NEMA 17 stepper motor with an A4988 or DRV8825. Note that you can also use the analog pins of the Arduino as digital outputs if you do not have enough pins available.
Why we need UNL2003?
Microcontroller and Microprocessor have an internal program or as we can say a set of functions, which control the voltage at the output and input pins of a single Control Unit. These control functions also help us to generate the timer, PWM, interrupts, and switching method internally without affecting the whole controller circuit. The issue of generating multiple functions was solved by a simple controller and processor.
Now the problem was how to control and minimize the circuit of high voltage DC devices. There was a wide usage of High voltage DC motors due to its energy efficiency. A logical circuit with Darlington transistor (NPN) was used to control the High DC load approximately equal to 50V and 500mA. This circuit could only be used for a single load. To solve this issue an IC name ULN2003 was introduced.
ULN2003 Introduction
ULN2003 comes with multiple functions. It has seven Darlington transistors installed which could help to control 7-Loads at the same time. It comes with 16 pins and multiple packings like SOP, PDIP, TSSOP or SOIC. This could help the user to install the IC with any circuit without taking too much space as a transistors circuit. The output power source could apply separately to all the outputs but the input will be the same as all microcontrollers and microprocessors.
The voltage range for any load is 50V but the current range is 500mA which could be increased by combining the multiple output pins. ULN2003 comes with internal safety protection from back emf. It has an internal flyback protection system which gives protection to the device.
Pinout of ULN2003 IC
PIN CONFIGURATION Description
FEATURES of ULN2003 IC
- It is able to handle the high DC voltage range of about 50V maxima
- It comes in another version with a voltage range of 100V.
- The current handling system is also 500mA for each input.
- The range of current could be increased by using the two pins for the same load.
- Comes with an internal clap diode to protect the device from Back EMF Protection
- ULN2003 has an internal flyback system protection and a pin too which can be used for an inductive load.
- We can control by any low voltage device like Arduino, Microprocessor or any other controller or IC.
- It is available in all kind of packages like SOP, PDIP, TSSOP or
- ULN2003 output is compatible with all the TTL and 5-V CMOS logic
- It operates without using any power source attached directly to it.
WHERE AND HOW TO USE ULN2003?
ULN2003 could be use any point where we need to control the high DC volts approximately 50V. To use this IC there are some rules which we need to follow to make it work perfectly. Attach any IC or Controller as an Input Source to provide the logical signal to the Input Pins. Then Attach the one end of the load with the output pin. Attach the other end of the load with the Power source of 0 – 50V. Then attach both Grounds of Controller and Power Source with ULN2003 Ground pin to keep in sync with the ULN2003. There is a pin as COM (Pin 9). Attach this pin with the ground through a button.
Proteus Simulation
This button could be used to bypass all the pins and could produce the output. In the case of inductive load protection, this COM pin will be effective for IC safety. The power source of each motor could be different, but the ground should remain common.
APPLICATIONS of ULN2003
- 7-relays can be controlled with a single ULN2003
- It is mostly used to control the stepper motor.
- Inductive loads are also easy to control by using ULN2003
- High load LED Bulbs can be controlled through it.
- Efficient to use Logic Buffer in mostly Digital Electronics.
- It has wide use as a torch sensor with the microcontrollers.
EXAMPLE to Control Multiple loads
We could handle multiple devices with this single device. Just attach the different loads with a different power source with ULN2003. Then Connect each load with a different power source. After that Common the ground with IC. Each Input pin controls each output. Now turn that device on which need to be on by applying High Logic on that input. To test all the pins at the same time or turn on all the devices at the same time Apply High logic at that input. During using ULN2003 always keep in mind that all the power and controllers Ground should be common with ULN2003. If Ground will not common with ULN2003 than it will have no control over the output.
Figure 3: Multiple loads with a single IC
ULN could control multiple devices at the same time or it can also control each device at a different time too. The usage of ULN2003 is easy but due rules and regulations of every IC ULN2003 also need to be followed by its requirement. If a user is not following the rules than it could get burn due to the inductive load or any other power circuit issue. If it isn’t burned than you are lucky and change the pins according to the above, we mentioned.
Tutorials and Projects
You can refer to this guide :
DataSheet
UNL2003 2D Diagram
Comments
Dc Motor Driver Circuit Using Uln2003 Cable
- When you need to be able to reverse the DC motor then the complexity of a H-bridge is needed. When all you need to do is control the motor or even PWM it then there's this wonderful 3-pin IC called a 'MOSFET'. Yeah, and what's more, they are usually rated to handle many 10's of amps so that motor stall should never be a problem. You can even drive them from 3.3V with only a single I/O.
Ok, sounds over the top maybe? But it's true and it is exactly what I would use. Why use a space pen when a pencil will do?
Thank you all
Here is the article.
https://electrosome.com/dc-motor-l293d-pic-microcontroller/
You just replace that micro with a Stamp (BS1 to BS2p40) or Propeller.
The article is the level of this forum.
So. That is how to connect Parallax micro to DC motor.
There may still be a Parallax article or Nuts and Volts or Application Note out there somewhere like it.
Happy holiday! 14 days til Christmas!- So you are not really interested in finding out how to do it then?
How hard is it to connect the 2 wires of a DC motor?
I've not seen you follow through on any of your 'problems'.
Maybe you just like creating a stir?
I could be wrong but moderators please take note.
Happy holiday! - edited 2018-12-10 - 04:34:41'When you need to be able to reverse the DC motor then the complexity of a H-bridge is needed'
Thank you for that.
Will connect up some of this stuff.
Using a 4.5 volt 3 AA battery box to power motor.
It's a motor on a Tamiya wheel ratio kit. Turns some different diameter wheels with rubber bands for belts.
No 'belts' on it.
Happy holidays! - For those of you wandering through this thread looking for suggestions and examples of DC motor control using a Basic Stamp or Propeller, do have a look at the Nuts and Volts columns, particularly Vol 1, #23. This is a long-running series of columns in Nuts and Volts magazine most by JonnyMac on a variety of topics, complete with easy to understand discussions and explanations and practical examples.
- microcontrolleruser,
I thought you wanted to know how to connect 2 motors to an L293D and I have seen much better tutorials than the one you linked to.
https://itp.nyu.edu/physcomp/labs/motors-and-transistors/dc-motor-control-using-an-h-bridge/
Mike,
That's a good article and it even has something for Erco (controlling 2 motors with relays through a ULN2003).
Thank you Mike
There we go a Nuts and Volts article on it. Suspected there was one out there.
Probably an application note too.
Thank you Genetix
'I thought you wanted to know how to connect 2 motors to an L293D'
Not me. That would be like saying I wanted to hook up four because I looked at ULN2003 first.
Nope. Just one motor.
I do not think there is an IC for just one motor.
The L293D just throws in a circuit for extra motor. That was a common sense thing to do.
Happy holidays!
Here is the L293D in a nutshell.Control Signals and Motor Status
RB0/IN1 RB2/IN2 Motor Status
LOW LOW Stops
LOW HIGH Anti-Clockwise
HIGH LOW Clockwise
HIGH HIGH Stops