Hello.
I have a digital DC ammeter (0-2)A. It is a ICL7017 based meter.
I want to convert it (0-20)mA.
I found a schematic (click here). In this, to get a 20mA scale the shunt should be 10 OHM (BOTTOM SEGMENT 9+0.9+0.09+0.01 = 10). And the upper segment resistance is 90+900+470K = 470.990K approximately 471K.
I have another 20mA ammeter. In this ammeter, the SHUNT is 10 OHM. But the upper segment resistance is 220K.
For the same IC 7107 and for the same scale 20mA, how come the two resistors are different.??
How the ammeter is not effecting the difference 471K and 220K??
I have a digital DC ammeter (0-2)A. It is a ICL7017 based meter.
I want to convert it (0-20)mA.
I found a schematic (click here). In this, to get a 20mA scale the shunt should be 10 OHM (BOTTOM SEGMENT 9+0.9+0.09+0.01 = 10). And the upper segment resistance is 90+900+470K = 470.990K approximately 471K.
I have another 20mA ammeter. In this ammeter, the SHUNT is 10 OHM. But the upper segment resistance is 220K.
For the same IC 7107 and for the same scale 20mA, how come the two resistors are different.??
How the ammeter is not effecting the difference 471K and 220K??