stepper motor
TRANSCRIPT
KHOA C KH CH TO MY B MN C IN TBO CO MN HC
SERVO IN THY - KH TI:
IU KHIN NG C BC
GVHD:PHM BCH DNG SVTH: H L THIN BNH 06111 006 TRN HU PHC 06111078 NGUYN NGC TN 06111091 TP. HCM, Thng 4 2010
TNG QUAN
i nt v ng c bc Cch iu khin ng c bc Cc ch hot ng Thit k phn cng Kt qu
I NT NG C BC
Theo cu to cun dy, c cc loi:
n cc (Uni-polar Stepper Motor)Lng cc (Bi-polar Stepper Motor) a cc (Multi-polar Stepper Motor)
I NT NG C BC
Cc thng s c trng:
phn gii (Resolution): Re=1.80, 3.60, 7.50 in p nh mc
Dng in nh mcTn s p ng cao nht (fmax)
CCH IU KHIN
iu khin ng c bc n cc bng cch cp xung ln lt cho cc pha. Tng gim khong thi gian gia cc xung iu chnh tc ng c.
i chiu cp xung o chiu chy ng c.Trong m hnh dng vi iu khin 16 bit iu khin ng c.
CCH IU KHIN
Chia 1 bc ca ng c ra thnh 8 bc nh ta dng 8 transistors cng sut D468 mc song song cp xung cho cho mi pha, do phi dng tt c 32 transistors cho 4 pha ca ng c.
CCH IU KHIN
Tnh ton in tr RB mc vo cc B ca D468 sao cho dng ICE qua n t gi tr ph hp: + IB = Im
IA
CCH TNH IN TR IBE TRONG MCHGM CC BC SAU:
Bc 1: Chia full step ca ng c bc ra thnh 8 gc bng nhau. Do mi gc l 90/8= 11.25o .
CCH TNH IN TR IBE TRONG MCH
Bc 2 : tnh ICE V IA + IB =1 T mi v tr mi xc nh trn ta c: IA = sin IB = cos Vy ICE (mA) = IB =cos
Bc 3 : tnh denta ICE.V mi ln ta kch ng thi 8 trasistor ngha l tng dng ICE lun lun bng 1. do ta phi tnh denta sao cho tng cc denta bng 1. denta c tnh nh sau Denta VBE ICE = VBE ICE(i ) - ICE(i-1)
CCH TNH IN TR IBE TRONG MCH
Bc 4 : tnh VBE T datasheet ca transistor d468 ta c s ph thuc gia VBE v ICE ( tnh 25 C)
th 2: S ph lin h gia ICE v VBE T ICE tnh trn ta chng ln v xc nh c VBE
CCH TNH IN TR IBE TRONG MCH
Bc 5 : tnh HFE T datasheet ca transistor D468 ta c s ph thuc gia HFE v ICE ( tnh 25 C)
th 3: S ph lin h gia ICE v HFE
CCH TNH IN TR IBE TRONG MCH
Bc 6 : tnh I BE(mA) Ta c I BE = dentaICE / HFE Bc 7 : tnh RB RB = (5 - V BE )/ I BE
Bc 8 : tnh Rtt V in tr c tiu chun ha. Do ta ly gn ng in tr v chp nhn sai s nht nh. T cc bc trn ta tnh c bng gi tr
CC CH HOT NG
CH FULL-STEP 1
CH HALF-STEP 2CH OCT-STEP
CH FULL-STEP 1
CH HALF-STEP 1
CH OCT-STEP
LU GII THUT CH OCT-STEP
THIT K PHN CNG
C rt nhiu IC dch nh l 74HC164, 74HC254, Dng IC 74HC595 iu khin y l IC dch bn trong l nhng Flipflop D ni ghp cht d liu
IC DCH 74HC 595
Chn IC 74HC595 v c nhng u im so vi cc loi IC khc
V chc nng c hai IC u l IC dch
IC DCH 74HC 595
Cc d liu vo l ni tip ra song song
Gia cc thanh ghi dch v ng ra c mt cht. iu ny cho php thay i linh hot d liu trong cc thanh ghi v n nh trng thi logic ng raTuy nhin 74HC595 c chn 13 (enable output) tc ng mc thp, gip cho vic iu khin d dng hn. n hin ng ra khi cn thit Trong khi 74HC164 khng c chn enable output cho nn tn hiu ra s c hin th
THIT K PHN CNG
8 transitor s chia dng IA + IB = Im Led c ni song song vi transitor hin th
THIT K PHN CNG
Kt qu board cng sut
THIT K PHN CNG
ng dng mch KIT Atmega8
LU GII THUT CHO TON CHNG TRNH
KT QU
Chy c Fullstep, Haft-step, Octstep C 32 led hin th qu trnh chy Cc led hin th ch