Hey I am doing a project using the TCRT5000 which is a phototranistor with an IR LED. I need to measure the current through the transistor. We get told to add a resistor and measure the voltage accross it using a voltmeter (and then I= V/R) instead of measuring current directly using a ammeter.

So I am curious, why it is better to use the voltage approach over the direct current measurement?

Also how would I determine what the optimal value of that resistor should be?

Thank you,

A lost, confused student

So I am curious, why it is better to use the voltage approach over the direct current measurement?

Also how would I determine what the optimal value of that resistor should be?

Thank you,

A lost, confused student

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