Low-Cost Machine Sorts Resistors at a High Speed

If your resistors aren’t properly separated, but instead reside in a box or bag, picking out the right ones to use can be a tedious process. Even if you've memorized the color codes, these bands can be difficult to see and actually measuring each one with a multimeter can be quite time consuming. As a solution to this problem, Ishaan Adarsh came up with his own resistor sorter.

Resistors are first dropped down the machine’s top funnel, coming to rest on a servo-actuated pad underneath the funnel’s exit. Two servos then make contact with both of the resistor’s leads, reading it with a voltage divider circuit. When analyzed, the bottom pad is then pulled away, allowing it to drop to a servo-driven decision plate that feeds it one way or another depending on if it’s in range.

Adarsh claims the device can analyze resistors at a rate of three seconds each, significantly faster than he’s able to measure them himself using a multimeter. Everything is controlled via an Arduino Mega, while user input is provided by a numerical keypad and LCD output. You can see it demonstrated in the first video below, with more explanation of how it works in the second clip.