Simple Motor Stepper Controller Circuit

The circuit shown above can be used to control a unipolar stepper motor which has FOUR coils (I've swiped it off an old fax machine). The above circuit can be for a motor current of up to about 500mA per winding with suitable heat sinks for the SL100. For higher currents power transistors like 2N3055 can be used as darlington pair along with SL100. The diodes are used to protect the transistor from transients.

Activating sequence:-

Inputs		Coils Energised
D0	D1
0	0	A,B
0	1	B,C
1	0	C,D
1	1	D,A

To reverse the motor just reverse the above sequence viz. 11,10,01,00.

Alternately a 2bit UP/DOWN counter can also be used to control the direction , and a 555 multi-vibrator can be used to control the speed.

Via: http://www.electronic-circuits-diagrams.com/robotimages/robotckt1.shtml

IC SN74194 Stepper Motor Circuit

Sirkuit ini adalah diagram rangkaian driver untuk mengatur kecepatan motor pada Stepper motor. Ini sirkuit motor dapat mengendarai motor untuk 12v 24V. Uji seri ditempatkan berbeda dan menunjukkan SN7474 dalam bentuk blok logika dan lampu LED yang digunakan untuk menunjukkan kumparan motor dihapus. Stepper motor sirkuit osilator menggunakan IC 555 astabil menghasilkan serangkaian pulsa clock diumpankan ke pin 11 dari sirkuit terpadu SN74194. Setiap kali pulsa clock pergi TINGGI (positif) di negara itu di terminal OUTPUT TINGGI dari SN74194 itu (PIN 12, 13, 14, 15), dialihkan, baik UP atau DOWN y satu tempat. Mengacu pada "Motor Stepper Supir Bentuk gelombang" Diagram. Pergeseran arah dikendalikan oleh sebuah saklar S2. Berikut ini adalah gambar skematik:

IC SN74194 Stepper Motor Circuit

Ketika S2 di posisi tengah OFF TINGGI-kondisi keluaran akan tetap berada di posisi terakhir dan motor akan berhenti. Ketika dasar Q6 adalah pergeseran ke PIN RENDAH 12-15 - 14 - 13-12. Ketika basis Q7 adalah pergeseran ke PIN 12 RENDAH - 13 - 14 - 15 - 12. Arah dari pulsa pergeseran menentukan arah putaran motor. Pulsa dari OUTPUT dari SN74194 empat segmen diberi makan ULN2003 Driver. Ketika masukan dari segmen adalah TINGGI, maka akan mengaktifkan transistor Darlington dan OUTPUT akan melakukan arus melalui salah satu kumparan motor. Sebagai motor gulungan AKTIF untuk mengikuti motor berputar langkah-langkah.

Sumber: home.cogeco.ca

Rangkaian Unipolar Stepper Motor Driver

Rangkaian Unipolar Stepper Motor Driver

Basic Controls For The Stepper Driver

The direction is selected by an ON-OFF-ON toggle switch.
The stepping rate is shown being set by a 1 Megohm potentiometer (RT). Using the component values shown for R1, RT, R2 and C1, the calculated step rate range is between 0.72 steps per second (1.39 seconds) to 145 steps per second.

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Basic Stepper Motor Driver Operation

1. The LM555 (IC 1) astable oscillator produces CLOCK pulses that are fed to PIN 11 of the 74194 (IC 2) shift register.
2. Each time the output of the LM555 timer goes HIGH (positive) the HIGH state at the 74194's OUTPUT terminals, (PIN's 12, 13, 14, 15), is shifted either UP or DOWN by one place.
   The direction of the output shifting is controlled by switch S1. When S1 is in the OFF position (centre) the HIGH output state will remain at its last position and the motor will be stopped.
   Switch S1 controls the direction indirectly through transistors Q2 and Q3.
   When the base of Q2 is LOW the output shifting of IC 2 will be pins 15 - 14 - 13 - 12 - 15; .etc.
   When the base of Q3 is LOW the output shifting of IC 2 will be pins 12 - 13 - 14 - 15 - 12; .etc.
   The direction of the output's shifting determines the direction of the motor's rotation.
   
3. The outputs of the 74194 are fed to four sets of paralleled segments of a ULN2803 Darlington driver (IC 3).
   When an input of a ULN2803 segment is HIGH, its darlington transistor will turn ON and that OUTPUT will conduct current through one of the motors coils.
   
4. As the coils of the motor are turned ON in sequence the motor's armature rotates to follow these changes. Refer to following diagram.