Mfundo yogwirira ntchito ndi kapangidwe ka sensa yokakamiza ya capacitive

Sensor yokakamiza mphamvu imapangidwa ndi zidutswa ziwiri zoyenda (diaphragm yachitsulo yosalala), zidutswa ziwiri zokhazikika (chophimba chachitsulo pagalasi lopindika pa diaphragm yosalala yapamwamba ndi yotsika), malo otulutsira ndi nyumba, ndi zina zotero. Ma capacitor awiri otsatizana amapangidwa pakati pa mbale yosuntha ndi mbale ziwiri zokhazikika. Pamene kuthamanga kwa intake kumagwira ntchito pa diaphragm yosalala, diaphragm yosalala imapanga kusuntha, komwe kumafunikira kuchepetsa mtunda ndi chidutswa chimodzi chokhazikika, ndikuwonjezera mtunda ndi chidutswa china chokhazikika (chingawonetsedwe ndi pepala). Mtunda pakati pa ma electrode awiri achitsulo ndi chimodzi mwazinthu zofunika kwambiri zomwe zimakhudza capacitance, mtunda umawonjezeka, capacitance imachepa, mtunda umachepa, capacitance imawonjezeka. Kapangidwe kamtunduwu kamatchedwa kapangidwe kosiyana komwe magawo a zinthu ziwiri zomverera amasinthidwa ndi kuchuluka komweko koma mosiyana chifukwa cha kuchuluka komwe kumayesedwa.

Ngati diaphragm yosalala yayikidwa pakati pa kupanikizika kwa mbali ndi kupsinjika kwa mlengalenga (m'mimba mwake mwa diaphragm yosalala ndi wamlengalenga), kupsinjika komwe kumayesedwa ndi tebulo; Ngati diaphragm yosalala yayikidwa pakati pa kupsinjika kwa mbali ndi vacuum (m'mimba mwake mwa diaphragm yosalala imadutsa mu vacuum), kupsinjika konse kumayesedwa. Mphamvu ya capacitor ndi yofanana ndi dielectric ndi malo ake ogwira ntchito pakati pa mbale ziwiri za capacitor, ndipo motsutsana ndi mtunda pakati pa mbale ziwiri, ndiko kuti, C=ε A/ D, pomwe ε ndi dielectric constant ya dielectric, A ndi malo ogwira ntchito pakati pa ma electrode awiri achitsulo, D ndi mtunda pakati pa ma electrode awiri achitsulo. Kuchokera pa ubale uwu, zitha kuwoneka kuti pamene magawo awiriwa sakusintha ndipo gawo lina likugwiritsidwa ntchito ngati chosinthika, capacitance idzasintha ndi parameter yosintha.
Pali mitundu yambiri ya ma circuit oyezera omwe amagwiritsidwa ntchito ndi capacitive pressure sensor. Tiyeni titenge chitsanzo cha bridge circuit kuti tifotokoze mfundo yogwirira ntchito ya capacitance differential sensor measuring circuit. Chifukwa capacitance ndi AC parameter, mlatho umayatsidwa ndi AC kudzera mu transformer. Transformer coil ziwiri ndi capacitance ya mlatho, pamene palibe inlet pressure, mlatho uli bwino, ndi ma capacitance awiri ndi ofanana ndi C0, pamene pressure effect, imodzi mwa capacitance value ya C0 + delta C, ina capacitance value ya C0 - delta, C (delta C ya external pressure yomwe imayambitsidwa ndi kusintha kwa capacitance), ndi bridge out of balance, Pamene capacitance value ili pamwamba, voltage nayonso imakhala yokwera, ndipo kusiyana kwa voltage kumapangidwa pakati pa ma capacitor awiriwa, komwe mlatho umapanga voltage output U yomwe imayimira intake pressure.