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Precision Control for DC Motors

Get the right spin every time!

Precision Control for DC Motors
This control circuit will provide the correct rotational speed and direction of a 12-V DC motor. Nothing special in that? But there is definitely, when you consider the multitude of potential options for actuating the motor. You can adjust the speed manually with a potentiometer (‘pot’), using a DC voltage level between 0 and 5 (or 10 V) or even digitally using I2C.
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(Reference voltage = 4.93 V)
* Supply voltage: 12 V
* Maximum output current: 2 A
* Minimum supply current: 11.2 mA
* PWM range: 0 – 100 %
* External control voltage:
0.16 V (PWM 0 %, 0/5 V range)
4.88 V (PWM 100 %, 0/5 V range)
0.27 V (PWM 0 %, 0/10 V range)
9.7 V (PWM 100 %, 0/10 V range)
* Input impedance (Pin 2 of K2):
6.43 kOhm (0/5 V range)
15.36 kOhm (0/10 V range)
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Component list
Component List
All SMD 0805, 150V, 5%, 0.1W)
R1 = 2.7k?
R2 = 8.2k?
R3,R4 = 11k?
R5 = 5.6k?
R6 = 2.00k?
R7 = 330?
R8 = 4.7k?
R9 to R14 = 10k?
R15 = 2.2k?
P1 = 5k SMD preset, Bourns 3314G-502E

C1 = 10nF 50V, X7R, SMD 0805
C2,C4,C6,C7,C8 = 100nF 50V, X7R, SMD 0805
C3 = 10µF, 16V, X5R, SMD 0805
C5 = 47µF, 6.3V, 0.5?, tantalum, SMD case B
C9,C10 = 220µF, 16V, 0.1?, tantalum, SMD case

D1,D2 = TS4148RY, SMD 0805 (Taiwan Semiconductor)
LED1 = LED, green
IC1 = SG3524D, SMD SOIC-16 (Texas Instruments)
IC2 = MC74HC4053ADTG, SMD TSSOP-16 (ON Semiconductor)
IC3 = AD5301BRMZ, SMD MSOP-8, only with I2C populating (Analog Devices)
IC4 = BD6222FP-E2, SMD HSOP-25 (ROHM)

K1A,K1B,K2 = 3-way PCB screw terminal block, 5mm pitch
K3,K4 = 2-way PCB screw terminal block, 5mm pitch
JP1,JP5,P6,JP7 = 3-pin pinheader, vertical, 0.1’’ pitch
JP3,JP4 = 2-pin pinheader, vertical, 0.1’’ pitch
JP1,JP3–JP7 = jumper, 0.1’’ pitch
PCB # 140562-1 from Elektor Store

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