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to drive dc motor using uln2003

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maddy.dreams

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hi..
i want to control i.e only to on n off a dc motor(walkman motor). its rating is 3-5v,500ma. i've left with only 2 ports(p1.5 n p1.6) of 89s52 uc.
plz give me the circuit diagram to drive motor using uln2003..

thanx in advance..
Madhav :)
 
The TDA2003A has a max allowed collector current of 500mA when it operates poorly. Its max saturation voltage loss is 1.6V when its load current is only 350mA. Its max input voltage is 3.0V for only 300mA output.
Its output sinks towards 0V.
 
The ULN2003A has a built in base resistor of 2K7. Use two inputs and outputs in parallel. For max possible saturation apply +5V directly to the inputs.

As audioguru already mentioned the voltage loss will be 1.6V (darlington), but still enough voltage to drive the motor.

Don't forget to connect the free wheeling diodes (pin9) to +5V. The motor is an inductive load.

There is no schematic necessary if you connect the motor like this: pins1 and 2 and 9 --> +5V (control input), first motor connection --> pins 15 and 16, second motor connection --> +5V
 
A bit doubt why he needs two pins to drive a motor unless he needs an H bridge to turn the motor on both directions from the two left pins.:)

just because the ULN2003A has base resistors of 2K7 and won't saturate at 5V input voltage. Using two pairs of transistors the current flow might be high enough to drive the motor.

Using an ULN2001A there wouldn't be a problem. It has no base resistors built in.

Boncuk
 
Why it must be ULN2003 ? Better use a H-Bridge like SN754410, for higher currents L298 or L6203 or LMD18200.

If you don't need directional control, just use a transistor (BJT NPN or N-MOSFET). Selection of the transistor
depends on the current your motor needs.
 
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Suitable transistor for 0.5A motor: You can try for example BC337, better the 0.8A version (Fairchild, ON Semiconductor) the version from NXP is only 0.5A and better to have a reserve. BC639 can be also used if your micro can source at least 20 mA on the output pin as the min. hFE is only 25. MOSFET is also a good choice, there are "logic level" MOSFETs that they need only 5V gate voltage to fully open (many common MOSFETs need 10V). Selecting one with low Rds-on assures minimal losses and warming when the MOSFET is open. The smaller MOSFETs are usually SMD components but you can take a bigger one in TO-220 package - for example I have RFP3055LE - it is of course overkill (11A, 60V max.) but not expensive and smaller MOSFETs are not necessarily much cheaper (if at all) (see: Digi-Key Corporation - USA Home Page, Mouser Electronics - Electronic Component Distributor) or there is a similar product from ST: STP16NF06L ( only $ 0.51/piece at Mouser).
 
Hi petrv I use the above technic you described.

I think OP is driving displays (SSD) as well so he may take the ULN to drive the displays.The remaining ULN pins taking the advantage to drive the motor as well.This way the design makes compact.

I just guess but not sure until OP give a clear idea.
 
hi all...

I am using ULN2003AP to drive my Dc motor. so i need to know clearly that..

1. What is the full form of 'ULN'..

2. What that 2003, AP and all indicates..

3. Instead of using ULN2003 to drive 12V DC motor what other ICs can be made used of..

Waiting for reply...

Regards,
Shining Star:)
 
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1. What is the full form of 'ULN'..
We don't know what "full form" means in English.

2. What that 2003, AP and all indicates..
We don't know what you are asking about in English.

3. Instead of using ULN2003 to drive 12V DC motor what other ICs can be made used of?
A ULN2003A has a max allowed continuous output current of only 500mA.
Texas Instruments make some ICs that might be better but I don't know the part numbers.
 
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