Hi,
I am trying to make a project whereby room temperature is displayed in digital form on leds.For temperature sensing purposes I have used LM35 whose ouput is given to adc0804.The circuit works fine on breadboard but after mounting it on general purpose pcb ,it is showing 10 times more temperature.Thinking there might be a problem with my soldering, i got a second general purpose pcb mounted made by a professional.Again the displayed temperatute is 10 times more.So I am sure that the components have been connected properly on pcb. If i hold a matchstick near LM35 there is an increase in the digital ouput.I believe the problem could be due
to parasitic capacitances being not present on pcb. I dont know much about these parasitic capacitances and although i know i need to add capacitors somewhere in the circuit ...i dont know where...
I am trying to make a project whereby room temperature is displayed in digital form on leds.For temperature sensing purposes I have used LM35 whose ouput is given to adc0804.The circuit works fine on breadboard but after mounting it on general purpose pcb ,it is showing 10 times more temperature.Thinking there might be a problem with my soldering, i got a second general purpose pcb mounted made by a professional.Again the displayed temperatute is 10 times more.So I am sure that the components have been connected properly on pcb. If i hold a matchstick near LM35 there is an increase in the digital ouput.I believe the problem could be due
to parasitic capacitances being not present on pcb. I dont know much about these parasitic capacitances and although i know i need to add capacitors somewhere in the circuit ...i dont know where...
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