{"id":1879,"date":"2024-06-28T07:30:23","date_gmt":"2024-06-28T07:30:23","guid":{"rendered":"https:\/\/iotthinghub.com\/?p=1879"},"modified":"2024-08-11T17:16:24","modified_gmt":"2024-08-11T17:16:24","slug":"current-sensor","status":"publish","type":"post","link":"https:\/\/iotthinghub.com\/?p=1879","title":{"rendered":"Current Sensor"},"content":{"rendered":"\n

ACS712 is a hall effect-based linear current sensor that can measure both AC and DC current. Let\u2019s look at the connection and steps to interface.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

For a unipolar supply voltage, it nominally remains at VCC\u2044 2. Thus, VCC = 5 V translates into V IOUT(Q)<\/sub> = 2.5 V. So for 0A the reference voltage is VADC<\/sub> = 2.5V and ADC Value is 512.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Current sensing value is<\/p>\n\n\n\n

Vout<\/sub> = (VCC<\/sub>\/2) + Sensitivity*Current , Here VCC <\/sub>= 5V<\/p>\n\n\n\n

Here, ADC Value = Vout<\/sub> * (1024\/5)<\/p>\n\n\n\n

                            = ((VCC<\/sub>\/2) + Sensitivity*Current)* (1024\/5) =  ((5\/2) + Sensitivity*I)* (1024\/5)<\/p>\n\n\n\n

                             = 512 + (Sensitivity*I*1024)\/5<\/p>\n\n\n\n

Current I = (5\/(1024* Sensitivity))*(ADC Value-512) <\/p>\n\n\n\n

For ACS712ELCTR-20AT the sensitivity is 0.1 and the current value is Current I = (5\/102.4)*(ADC Value – 512)<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n
\nfloat current(uint8_t phase,uint8_t channel)\n{\n  float current;\n  uint16_t ADC_Value;\n  ADC_Value=read_adc(channel);\n  if(phase==AC_Current)\n\t{\n\t\tif(ADC_Value>=512)\n\t\t\t{\n\t\t\t current=(ADC_Value-512)*(5\/(ADC_Scale*sinsitivity)); \/\/VCC=5V\n\t\t\t}\n\t}\n     else if(phase==DC_Current)\n\t{\n\t\tcurrent=(ADC_Value-512)*(5\/(ADC_Scale*sinsitivity)); \/\/VCC=5V\n\t}\n\t\n return current;\n}\n<\/pre><\/div>\n\n\n
Here for ACS712-05BT sensitivity 0.185, ACS712-20AT sensitivity 0.1 and ACS712-30AT sensitivity 0.066.<\/p>\n\n\n\n
Set timer0 overflow vect and at every interrupt service routine read the current. Let\u2019s look at the main program-<\/p>\n\n\n
\n  #include<avr\/io.h>\n  #include<stdio.h>\n  #include<avr\/interrupt.h>\n  #include"adc.h"\n  #include"lcd.h"\nfloat VA=1,Amp_ac,Amp_dc,volage=220;\nchar str[20];\nint main(void)\n  {\n   LCD_INIT();\n   adc_init();\n   LCD_Clear();\n   timer_ISR();\n   while(1)\n    {\n      sprintf(str,"AC Current=%.2fA",Amp_ac);\n      LCD_write_string(1,1,str);\n      sprintf(str,"DC Current=%.2fA",Amp_dc);\n      LCD_write_string(1,2,str);\n      _delay_ms(1000);\n    }\n  return 0;\n}\nISR(TIMER0_OVF_vect)\n{\n\tAmp_ac=current(1,0); \/\/AC Current(1) with channel 0\n\tAmp_dc=current(2,1); \/\/DC Current(2) with channel 1\n\t\n}\n<\/pre><\/div>\n\n\n
Since we have a PDB supply is fixed at 220V, we can calculate the power = VIcos\u0553. If power factor cos\u0553=0.98 and V=220V then we can calculate the power from the equation.<\/p>\n\n\n\n
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download<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n
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Current Sensor.rar<\/a><\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
ACS712 is a hall effect-based linear current sensor that can measure both AC and DC current. Let\u2019s look at the connection and steps to interface. For a unipolar supply voltage, it nominally remains at VCC\u2044 2. Thus, VCC = 5 V translates into V IOUT(Q) = 2.5 V. So for 0A the reference voltage is […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-1879","post","type-post","status-publish","format-standard","hentry","category-adc"],"_links":{"self":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts\/1879","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1879"}],"version-history":[{"count":7,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts\/1879\/revisions"}],"predecessor-version":[{"id":2625,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts\/1879\/revisions\/2625"}],"wp:attachment":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1879"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1879"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1879"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}