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| and also the Fritzing scheme for closer reference; http://fritzing.org/ | | and also the Fritzing scheme for closer reference; http://fritzing.org/ |
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− | {{zip|ArduinoAmmeter.zip|118KB|Version from 05.02.2012}} | + | {{zip|ArduinoAmmeter.zip|118KB|}} |
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| =Resistor Values= | | =Resistor Values= |
| The values of the given resistors are in the breadboard | | The values of the given resistors are in the breadboard |
| picture | | picture |
− | (from left to right) 100K, 10K, 0.47 Ohm, 220 Ohm, 100K, 2.2K (twice). | + | (from left to right) 100K, 50K(10K/6.8K), 47(0.47/4.7) Ohm, 220 Ohm, 100K, 2.2K (twice). |
| Henceforth, I refer to them as R1, R2, R3, R4, R5, R6 und R7 respectively, | | Henceforth, I refer to them as R1, R2, R3, R4, R5, R6 und R7 respectively, |
| | | |
− | With those given values a maximum voltage of 55 Volt and
| + | The values of R2 and R3 depend from the range you are taking measurement. To decide their proper |
− | a maximum current of 10.6 Ampere can be measured. For different voltages
| + | value use the table below. Note that you must adapt also the Arduinocode accordingly; |
− | choose a different R2, für different currents a different R3.
| + | R2 refers to variable '''V10K_RESISTOR ''' and R3 is '''I0_47_RESISTOR''' |
| + | |
| | | |
| Following table lists different values of R2 and its corresponding maximum voltage; | | Following table lists different values of R2 and its corresponding maximum voltage; |
Zeile 46: |
Zeile 47: |
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| |} | | |} |
− | In case you choose a different value you have to adapt that in the Arduino source, respectively,
| |
− | Regarding R2, modify the initialization of variable V10K_RESISTOR,
| |
− | for R3 the variable I0_47_RESISTOR.
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| The value of the resistors R6 und R7 (here given as 2.2K) need not to be exactly like that, | | The value of the resistors R6 und R7 (here given as 2.2K) need not to be exactly like that, |
Zeile 73: |
Zeile 71: |
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| log permanent OFF | | log permanent OFF |
| + | |
| + | =Accuracy= |
| + | Alas, the values are not too accurate. Check out discussion and proposals |
| + | for bettery accuracy at following link |
| + | http://arduino.cc/forum/index.php/topic,140203.0.html |
| + | For one thing you can lower the resistor values when it is safe for your |
| + | application. |
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| =References= | | =References= |