Brad B
Member
I am working on my first project involving analog inputs and would apppreciate it if someone could verify my math before we make a purchase.
I have a 10k Ohm Pot that needs to control an analog input which requires a 0-20mA signal. I will be using a 12V supply voltage, and a calculated 475 Ohm resistor. The input card has 125 Ohms impedance.
So the circuit goes as follows:
12 Volt Supply
10K Ohm Pot
475 Ohm Resistor
125 Ohm Analog Input
0 Volt Ground
When Pot is off:
I = 12V / (O Ohm + 475 Ohm + 125 Ohm) = 20 mA
When Pot is fully on:
I = 12 V / (10000 Ohm + 475 Ohm + 125 Ohm) = 1.13 mA
Does this sound like it will work? Are there any caveats I should be aware of? Thank you for any imput!
P.S. I am not an electrician, but a CAD designer thrust into the world of PLC's.
I have a 10k Ohm Pot that needs to control an analog input which requires a 0-20mA signal. I will be using a 12V supply voltage, and a calculated 475 Ohm resistor. The input card has 125 Ohms impedance.
So the circuit goes as follows:
12 Volt Supply
10K Ohm Pot
475 Ohm Resistor
125 Ohm Analog Input
0 Volt Ground
When Pot is off:
I = 12V / (O Ohm + 475 Ohm + 125 Ohm) = 20 mA
When Pot is fully on:
I = 12 V / (10000 Ohm + 475 Ohm + 125 Ohm) = 1.13 mA
Does this sound like it will work? Are there any caveats I should be aware of? Thank you for any imput!
P.S. I am not an electrician, but a CAD designer thrust into the world of PLC's.