Avtomatlashtirish va boshqarish

MUNDARIJA:

(4.1) 20
(4.2) 21
(4.3) 21
(4.4) 21
T=t+273,15 (4.5) 22
(5.1) 23
(5.2) 24
(5.3) 25
26
5.1. Rasm. Tajribaviy simob termometrlar: 26
. 27
(5.4) 27
(6.1) 35
36
37
38
39
39
(6.2) 39
39
40
40
(6.3) 42
(6.4) 42
(6.5) 42
(6.5) natijani (6.4) ga quysak, quyidagiga ega bo`lamiz: 42
(6.6) 42
(6.7) 42
E(t,t0)+E(t0,0)=E(t,0) (6.12) 43
E(t0,t'0)+E(t'0,0)=E(tt,0) (6.13) 43
6.13 – rasm. Termojuft erkin uchlarining haroratini avtomatik kompensatsiyalash sxemasi 48
M_(айл)=С₁В₁I (7.1) 51
M_тес=С₂Еφ (7.2) 51
С₂Еφ=С₁BI (7.3) 51
u holda 51
(7.4) 51
φ=K·I (7.5) 51
bu yerda, 51
51
(7.6) 51
52
53
E₍t_,t₀₎-I·R_bD=0 (7.7) 53
yoki 53
E₍t_,t₀₎=I·R_bD (7.8) 53
(7.9) 53
bundan, 54
(7.10) 54
(7.11) 54
(7.12) 54
(7.13) 54
(7.14) 54
55
56
(8.1- rasm). 58
(8.1) 60
(8.2) 61
(8.3) 62
Rt=R0[1+At+Bt2+Ct3(t-100)] (8.5) 63
Rt=R0(1+At+Bt2) (8.6) 63
А = 3,96847·10 -3 1/°С; В = — 5,847·10-7 1/0С; С = — 4,22·10-121/°С. 63
aN1=(6,21-6,34)·10-3K-1 63
aFe=(6,25-6,57)·10-3K-1 63
δN1=1,18-1,38·10-7Ом·м; 63
δFe=0,55-0,61·10-7ОМ·м. 63
(8.7) 64
R₁I₁=R₂I₂ (9.1) 67
I_PR_P=I_t(R_t+2R_сим) (9.2) 67
(9.3) 67
Agar I₀=0,1₁=I_p ва I₂₌I_t bo'lsa, 67
R₁(R_t+2R_сим)=R_pR₂ (9.4) 67
(9.5) 67
Agar atrofidagi haroratni o’zgarmas deb hisoblasak, 2R_сим = соnst. 68
R_t=K·R_p-K₁=f(R_p) (9.6) 68
(9.7) 68
R₁=R₂ бўлса, 68
R+R_сим=R_p+R_сим (9.8) 68
R_t qarshilik o‘zgarganda, almashlab ulagich O‘ vaziyatda turganida, millivoltmetr orqali kuchi shu o‘zgarishiga to‘g‘ri mutanosib bo‘lgan tok 68
(9.9) 68
R_M(R₁+R_t)·(R₂+R₃)+R₂R₃(R₁+R_t)+R₁R_t(R₂+R₃) (9.10) 69
I=U_H/R_Н (9.11) 71
I=U_ў/R_ў (9.12) 71
R_ў=R_H·U_ў/U_H (9.13) 71
72
IR_t=U_ab=I_ўR_ab 72
yoki 72
IR_t=K·I(R_H+mR_пр), …. (9.14) 72
bu yerda, 72
_(9.15) 72
Qarshilik termometri bilan birga ishlovchi me'yorlovchi tokli o‘zgartkichning sxemasi 9.7 - rasmda ko‘rsatilgan. Bu o‘zgartkich sxemasiga va ishlash prinsipiga ko‘ra termoelektr termometr bilan bir komplektda ishlovchi me'yorlovchi o‘zgartkichga o‘xshash (9.1-rasmga karang). Bu sxemalarning farqi shundaki, o‘zgartkichda tuzatuvchi ko‘prik TK o‘rnida o‘lchov nomuvozanat ko‘prigi O‘K foydalaniladi, uning yelkalaridan biriga uch o‘tkazgichli sxema bo‘yicha qarshilik termo o‘zgartkichi R_t ulangan. Qolgan qarshiliklar manganindan yasalgan. R_l qarshiliklar ulovchi o‘tkazgichlar qarshiliklarini nominal qiymatga moslash uchun xizmat qiladi. Ko‘prikning ab diagonaliga o‘zgarmas tokning barqarorlashtirilgan U kuchlanishi ulangan. O‘zgartkichning chiqish toki 1_chiq ko‘prikning o‘lchov diagonalidagi Ucd kuchlanishga mutanosib va ular orasidagi munosabat (9.16) ga mos holda berilishi mumkin: 73
I_чиқ=K·U_cd (9.16) 73
I_чиқ=K_k·K·R_t (9.17) 73
73
М₁=С₁В₁1₁ (9.18) 74
М₂=С₂В₂1₂ (9.19) 74
С₁В₁I₁=C₂B₂I₂ (9.20) 74
Bu tenglamadan 74
(9.21) 74
(9.22) 75
B=f(φ) bo’lgani uchun 75
(9.23) 75
Shuning uchun, 75
(9.24) 75
(9.25) 75
φ=f(R_t) (9.26) 75
(10.1) 78
(10.2) 78
(10.3) 78
(10.4) 79
(10.5) 79