Hello Guest it is July 21, 2019, 07:30:22 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - helow

Pages: 1
1
hi

thanks for your reply. but how is more batter to use diodes? Please what mean by "reverse biased for the back EMF". And again i am asking about the measures to protect the transistors from being burnt as described in following sentence.


"The diodes are a feature typical of circuits that handle magnetic coils, that is inductive circuits. In this context, the motor windings are the inductive element. Capacitors provide a means for the storage of electrical charge, inductors provide a means for storage of electrical current. The driving current causes a magnetic field to be built up in the coil. As soon as the drive is removed, the magnetic field collapses and causes the inductor to release its stored current. Semiconductors are particularly sensitive to these currents (they briefly become conductors and then become permanent nonconductors!). The diodes provide a mechanism to safely shunt these currents away and, thus, protect the transistors and the computer."

how the motor coil's conman wire and the four diodes wires will be used.

 

2
General Mach Discussion / running unipolar stepper motor with TIP120
« on: June 25, 2010, 09:00:27 AM »
hey

there are two circuits using same transistor but one of them do not have diodes. i read bout these diodes as following:

The diodes are a feature typical of circuits that handle magnetic coils, that is inductive circuits. In this context, the motor windings are the inductive element. Capacitors provide a means for the storage of electrical charge, inductors provide a means for storage of electrical current. The driving current causes a magnetic field to be built up in the coil. As soon as the drive is removed, the magnetic field collapses and causes the inductor to release its stored current. Semiconductors are particularly sensitive to these currents (they briefly become conductors and then become permanent nonconductors!). The diodes provide a mechanism to safely shunt these currents away and, thus, protect the transistors and the computer.

but in second circuit there is not diodes. why. how much important to use these diodes. if not to use diodes then which are general measures to save transistors?

and there are some detail about earth wires:

You should also note that ground for the transistors must be made common between the parallel port (say at pin 25) and the motor power supply. An additional wire with an alligator clip can be used to provide access to the ground for the motor power supply. So, on the motor side of the circuit we have six wires, one for each coil, one for ground and one for the motor voltage on the shunt diodes. The motor (positive) voltage supply is provided through the common coils.

I am not clear about coil wires which has diodes and another alone wire. Please tell me in detail about these wires.
and also tell me about connection of motor with circuit which has not diodes.




http://www.forth.org/fd/Step.html

3
here is pic of my motor

4
hi

thanks very much for your guidance. you are right i think, i have read about printer's data pinout, and there is not any pic like step and direction as in floppy drive. And i have not yet purchase printer formated pcb card and now i will not purchase it. I also have try to run 6 wire motor with small floppy drive and it only run buildin motor.  I think it generate low powered pulses. is there any way to powering up current coming to wires of motors.

5
hi

i have one taken from laser printer, has six wires, two are common called ground and other are for four coils. laser printer has two electronic pcb boards. power supply and data boards. i want to use data board to drive stepper motor. but i want to know about about power and data connector pins.

6
hi

i have got a stepper motor(i think it is 12V) from a laser printer. I am thinking to run it through large floppy drive (about 5"), but i think it could not run it with full power. thats why i want to use printer's data pcb board to run it. but i need some guide about pins of data and power connector. plz may you help me.

Thanks in advance


Asad

Pages: 1