How to input a current reading via ADC

[TedO]

Hi to all,

I have made up a bench power supply and am using the PIC16F690 with LCD output to display voltage output which was relatively easy. I would also like to display the amount of amps that is being drawn.

What is the simplest way of reading the current being drawn using the ADC input on the PIC, have no idea where to start.

Would appreciate some help please.

Thank you.
Regards
Ted

[Benj]

Hi Ted,

The simplest way is to have a watty resistor with a very low resistance. The current flowing through the resistor is proportional to the voltage developed across the resistor.

V = I x R

I = V / R

You can then use an op amp to amplify the voltage to give you a nice reading you can use with a micro's analogue input.

Here are some simple circuits, 1B is how I might do things.

https://www.google.co.uk/search?q=curre ... TMn2QfM%3A

[TedO]

Thanks for the help Benj, will certainly use this method, will play around with it.

Much appreciated
Regards
Ted