GD11-17A Investigating Noise Control Measures for the GD11-17 Digital Motor Controller

The purpose of this project is to see which of the electrical noise-reducing measures taken on the GD11-17 project are most critical.

One-at-a-Time Tests
For each of the following steps, 1. take the action stated, 2. try running the circuit, and 3. put things back the way they were before going to the next step.

Replace the 100 ohm resistors with 1k ohm resistors.

Replace the 100 ohm resistors with 10k ohm resistors.

Remove the 0.1 uF capacitor between +4 V. and ground.

Remove the 0.1 uF capacitor between +5 V. and ground.

If there is a ferrite bead around the motor wires, remove it.

Drape the twisted-pair motor wires over the 7400 I.C.

Untwist the wires going to the motor. If the circuit still works OK, try draping the untwisted wires over the 7400 I.C.

If you didn't use a ferrite when you built the circuit initially, and the circuit failed when you untwisted the wires, try putting a ferrite bead over the untwisted wires, close to the motor.

Right at the power supply, connect both black power supply terminals together with a piece of wire, and then run a single wire from either of the black terminals to your ground on the breadboard. Also, connect a jumper between logic ground and motor ground on the breadboard.
Remove the snubber diodes.

Multiple-Noise-Control-Measure-Tests
One by one, undo each non-critical noise-control measure. These are the ones that didn't cause the circuit to fail when you removed them singly in the tests above. This time, however, do not put things back the way they were after you remove each noise-control measure. In other words, we're trying to see if removing multiple non-critical noise-control measures can cause the circuit to fail.

What did you find out? Write a brief explanation below.