Help me to fix a stepper motor driver

Hai evryone.

I have a sanyo-denki 5.1v,1A,2kg-cm six wired stepper taken from an old
dot matrix printer. Two wires are the center taps.
I am using the unipolar configuration.

We are using a "MINI 51" Evaluation Board Which consist of an Philips
p89c668h micro controller of 8051 architecture for generating
the signals for the stepper.

Now The problem is The driving ckt. I made one with 2803.
but the torque is low and the IC overheats quickly.
The power supply indicated the current drawing is 700mA.

Can i use TIP122 darlingtons for the job?
How can i increase the speed and torque of motor?

Plese help me.....
(I am a mech engg student.So please describe more)


Thanks in advance....

tip122 motor

Increasing output current with TIP120s(TIP122) is a good idea ..
Also, I would consider adding inverter gates - see picture below for an example of a stepper motor driver with inverter gates and TIPs - to avoid situation after power-on when all TIPs are on ..

Stepper Speed <--> Steps Frequency
The maximum RPM at which stepper motors will operate properly is quite low and the torque the motor can produce drops of rapidly as motor speed increases.
Testing may be needed to determine the the maximum CLOCK INPUT frequency for any given motor. Data sheets, if available, will also help determine this frequency.

Regards,
IanP

tip122 stepper driver

Thanks Ianp for help.

IanP said:

Also, I would consider adding inverter gates - see picture below for an example of a stepper motor driver with inverter gates and TIPs - to avoid situation after power-on when all TIPs are on ..
IanP

Click to expand...

Is it necessary to use an IC like 74175 ?

Can i directly connect the TIP122 s with the microcontroller?
I read somewhere that for increasing torque and speed we have to increase the supply voltage. Is it fine?
Did it burns my motor?
Also what is the procedure ? just increase the voltage?

Soory .I am very poor in electronics.

Jabir

stepper motor+driver+tip122

Microcontroller's outputs have their own lateches already implemented, so adding another latch (74175) "in series" with already "build-in" latch doesn't make much sens, unless you don't have enough pins and you use the 74175 latches as port exptension ..

TIP122 has internal base resistors and can be directly connected to microcontroller"s pin. Some microcontrollers to assert a "1" use internal weak pullup; in any case, adding 1-10kΩ resistor as external pullup (between output pin and +5V) wouldn't hurt and will only improve the way TIP122s are driven ..

First, make sure that at the current voltage level, say 12V, your power supply can supply enough current to drive this motor ..
On the other hand, increasing the supply voltage above the motor's rating can cause damage, so be very careful and if you do increase the voltage try to do it in steps ..

Regards,
IanP

stepper motor driver tip122

Hai IanP.

Please tell me the name of an inverter IC for this job .

did the inverter is a must ?

Thanks for suupport

tip122 driver ckt

Thanks inaP

I am going to use 7404.
I will mail you later after testing the ckt...

tip122 stepper

for driving a stepper motro high current bufer l293d is very useful it can handel upto 1am current and
u dont have to get into transistors

tip122 step motor

lunar said:

for driving a stepper motro high current bufer l293d is very useful it can handel upto 1am current and
u dont have to get into transistors

Click to expand...

thanks for the message abt my stepper driver....

But pls check the datasheets....L293d has a max current
500 mA.

Did you know the roll of that invertor ?
I cant understand IanP.
I am using the two coil exitation .ie there is always two '1' s.
When we use the inverter there is only a cyclic change ? right ?
then what is the advantage?


Regards

Jabir

advantage of stepper motor driver circuit

Hi

Ignoring microstepping, a stepper motor has three modes a) half step b) fullstep c) wave. You can see L297 datasheet to understand it better.

It is very easy to switch between these three modes if you are generating the pulses by uC.

At stationary position the current through the coil is governed by ohm's law i.e at 5.1 v the motor will take 1 A per coil. However as motor starts spinnig the inductive losses increase causing the current to drop. You should not increase coil voltage unless you use chopper based controller that works at high voltage but controls the current through the winding (just go through L297 / L298 datasheet).

Let us know if you have any more queries.


Thanks

increase ic of tip122

Hai every one.....

At last i did it.!!!!!!!Just similar to the ckt diag IanP send....
The ckt is very simple with four tip 122 darligtons and 4 resistances.
since the TIP have internal diodes there is no need of external diodes....

IanP said:

TIP122 has internal base resistors and can be directly connected to microcontroller"s pin. Some microcontrollers to assert a "1" use internal weak pullup; in any case, adding 1-10kΩ resistor as external pullup (between output pin and +5V) wouldn't hurt and will only improve the way TIP122s are driven ..
IanP

Click to expand...

:

I connected 3.3 K resistores..With out them the stepper just vibrates only....

Thanks all for help.......

Regards

Jabir

7404 stepper motor

I think, u should buy the sanyo denki stepmotor driver.

Re: increase ic of tip122

Jabir said:

Hai every one.....

At last i did it.!!!!!!!Just similar to the ckt diag IanP send....
The ckt is very simple with four tip 122 darligtons and 4 resistances.
since the TIP have internal diodes there is no need of external diodes....

:

I connected 3.3 K resistores..With out them the stepper just vibrates only....

Thanks all for help.......

Regards

Jabir

Click to expand...

hi... can u send tip122 circuit to connect with microcontroller to control stepper motor?
my email id :lparthee@gamil.com

---------- Post added at 16:55 ---------- Previous post was at 16:52 ----------

thx i got the cirucit ...