SUMMARY

As a Hobby, I have devised this module and named it as “ DC Motor control using IC 7555. This simple circuit fabricated by me makes a DC motor to run in clockwise or anti-clockwise direction and stop it using a single switch. It provides a constant voltage for proper operation of the motor. LED 1 indicates that the motor is in stop condition. LED 2 indicates that the motor is rotating in Forward direction and LED 3 indicates that the motor is running in reverse direction.

Regarding the connection, I have wired the Timer IC1 as a monostable multivibrator to avoid false triggering of the motor, while pressing the switch S1. Its time period is approximately 500 milliseconds (ms).

Initially, the circuit is in reset condition with Q0 output of IC2 being high. Since Q1 and Q3 outputs of IC2 are low, the outputs of IC3 and IC4 are high and the motor doesn’t rotate. LED1 glows to indicate that the motor is in stop condition.

As I press the switch S1, the timer 555 (IC1) provides a pulse to decade counter CD4017 (IC2), which advances its output by one and its high state shifts from Q0 to Q1. When Q1 goes high, the output of IC3 at pin 3 goes low, so the motor starts running in clockwise (forward) direction. The forward rotation of the motor is indicated by Led 2.

Now when I press S1 again, the high output of IC2 shifts from Q1 to Q2. The low Q1 output of IC2 makes pin 3 of IC3 high and the motor doesn’t rotate. LED1glows (via diode D2) to indicate that the motor is in stop condition.

When the switch S1 is pressed once again, the high output of IC2 shifts from Q2 to Q3. The high Q3 output of IC2 makes pin 3 of IC4 low and the motor starts running in anti-clockwise (reverse) direction. LED3 glows to indicate that the motor is running in reverse direction.

As the switch (S1) is pressed again, the high output of IC2 shifts from Q3 to Q4. Since Q4 is connected to reset pin 15, it resets decade counter CD4017 and its Q0 output goes high, so the motor does not rotate. LED1 glows via diode D1 to indicate that the motor is in stop condition. Thereafter, the cycle repeats.

For not allowing the motor to run in reverse direction, I removed the timer IC4 along with resistors R5 and R7 and LED3 and connect ‘b’ terminal of the motor to +Vcc. Similarly if I do not want to operate the motor to run in forward direction, I removed timer IC3 along with resistors R4 and R6 and LED2 and connect ‘a’ terminal of the motor to +Vcc. I have utilized a 9V regulated power supply for a 9V DC motor.


By-
Arijit Kumar Bose
C/0 Dr. Debajyoti Bose
Abhirampur, PO Makdampur
Malda-732103, INDIA
arijit18@rediffmail.com

Attached Files

self.doc (36.0 KB, 1880 views)

 

I was wondering if anyone has got this to work? i was thinking of trying it.

thanks

 

It looks workable, why not try it? I don't have a small enough motor that could run from the outputs of a 555 to try it myself. Also, I have no real use for such a control just now but its a clever idea.
Klaus

 

I reguest to try it. For small applications I think its a good idea. I have devised this module after going through lots of discussions with my professors. I hope will like it.

 

i don't think it's worth the trouble. two IC3 chips are supposed to replace H-bridge while 555 has only about 200mA output (and 7555 is only 100mA max.). this looks much better http://kitsrus.com/pdf/k166.pdf and allows not only direction but also speed control.

 

No ICs needed
I would use a triple pole, triple throw, toggle switch and cross wire the switch to reverse polarity and just add the LEDs with resistors to indicate forward or reverse direction.

Use the center poles to attach the battery.
wire the left two poles one positive and one negative and wire to the right two poles, but reverse the wiring. It would then form an x so it is cross wired. hook the small motor to either set of outer poles. When you have the switch in the center position no current flows but if you throw the switch one way you will get the motor to turn in one direction. If you throw the switch to the opposite side you will then reverse the polarity and the motor will turn in the opposite direction. Simple.

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There are no stupid questions, if sincere.

 

I was wondering if anyone has got this to work? i was thinking of trying it.

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the quick brown fox jumps over a lazy dog

 

wouldn't this do..

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when you post that reply, im just kidding.

 

come on guys, this progect was just a time killer. give the poor lad a break.

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when you post that reply, im just kidding.

 

hah...exactly my idea, why waste time and $$ with ics when a switch will do just as well?

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-Ian

 

and a pot for speed variation

 

you project is very interesting but i think you could improve it. i think you should try to use a a temp sensor(lm35) to control the speed of your motor(has the temp goes high your speed increases and if it goes low it should decrease) this is just a suggestion

 

Check the dates on the posts. This thread has been dead for a year and a half.


Torben

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Curiosity was framed. Ignorance killed the cat.

 

How will u use an LM35 to control the speed of a DC motor, demonstrate it by using a schematic diagram so that I can understand it, matter of curiosity

 

actually i have a project like that given to me at school,but i'm supposed to use a temp sensor to control the speed of the motor and another interesting thing is that the motor's supposed to stop turning when there's no light at all,help out guys cause i really don't know how to turkle this lil monster.am eddison the new guy by the way.please email me:mphegolle@gmail.com