ahmed osama
Full Member level 6
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dear all
i have a pic 18f4550 , i am using its ADC + max232 and reading the data using rs232 in my pc
i am using 9volt battery then 7805 Reg as Vdd supply
my problem when the adc i/p is floating , i get an AC signal 50Hz about 2.5 Vp and when i touch the input i got a complete square signal 5Vp with 50Hz
i was going to use such system as a part of EGC project , when i touch the gnd by left hand and ADC i/p by my right hand i also got a complete square signal 5Vp with 50Hz ( i know egc needs extra circuits for filtering & amp.)
from where such AC signal came , is it AC signal coupled from my pc through Rs232 !!!
how could i solve that
thanks all
bye
i have a pic 18f4550 , i am using its ADC + max232 and reading the data using rs232 in my pc
i am using 9volt battery then 7805 Reg as Vdd supply
my problem when the adc i/p is floating , i get an AC signal 50Hz about 2.5 Vp and when i touch the input i got a complete square signal 5Vp with 50Hz
i was going to use such system as a part of EGC project , when i touch the gnd by left hand and ADC i/p by my right hand i also got a complete square signal 5Vp with 50Hz ( i know egc needs extra circuits for filtering & amp.)
from where such AC signal came , is it AC signal coupled from my pc through Rs232 !!!
how could i solve that
thanks all
bye