| ??? 03/25/06 11:48 Read: times |
#113056 - 7805 and get 10mA and 100mA Responding to: ???'s previous message |
Neil said:
0.010 Amps * 0.020 ohms = 0.0002 volts .2 millivolts is kind of tiny A gain of like 200 watch for noise from what you have said i got that, since the measured voltage would be too less(.2mV) for low CR, this voltage(.2mV) has to be safeguarded against noise issue. If this is what you describe, what could i do to achieve it? A careful PCB design (or) handling any design technique? could you give me some knowledge of how to do that. Kai Klaas said:
And thermo-potentials! I dont have any idea about it Kai. Could you give me some more info on 'how and where it would be developed in my circuit? Kai Klass said:
Why not using a simple 1k5 resistor for the 10mA constant current and a 150R resistor for the 100mA constant current, both in combination with +15V voltage source? Even with a 2Ohm contact resistance this would result in an error of only 1.3%, if remaining uncorrected On reading the above, could i take a 7805 and get 10mA and 100mA by using two resistors at its o/p? Can you tell me how did you get that error factor. suresh. |
