6. Calibration

Now it is time to calibrate the voltage regulators. We will get to plug in the battery, flip the switch, and see the output from the regulators! Definitely a much awaited moment. For these steps we will need a multimeter, and a screwdriver with a tiny flat bit. Tuning the voltage involves adjusting a tiny potentiometer and watching the output. Sometimes you might have to turn one way or another way. For safety, please never touch the conductive parts of the wires when the battery is connected. Make sure your battery pack is in good health before proceeding. Time to get going on it!

It’s time to calibrate the output voltages of the regulators. Bring your multimeter over to the power pack kit so far. We will be using a precision digital multimeter, but an ordinary multimeter will work just as well.

Attach the positive probe to the output from the smaller voltage regulator. Attach the negative probe to the ground wire.

Obtain your battery. The LiPo battery was not included in your kit, it has to be ordered sepparately. Your LiPo should be a 2 cell battery, that has nominal voltage of 7.4V. For the purposes of these tests, charge the battery beforehand.

Plug in the battery to the other end of the boom stopper.

Here is the moment of truth, when we will verify that everything is wired properly. Prepare to turn the switch ON.

Hooray! The switch lights up and nothing heats up or emits sound.

Observe the initial voltage of the regulator. Our reading shows 5.1V, but that’s only because we calibrated it beforehand ;). Yours will likely say something different.

Using a screwdriver with a small flat head bit, adjust the trimpot of the regulator. An output of 5.1V is desired, as it is within the safe range, and has a bit extra to account for any voltage drop.

The first regulator is complete. Now, turn off the power pack and unplug the battery.

Switch the positive probe to one of the other two wires. The last two wires will be outputs from the large voltage regulator. Next, plug in the battery and flip the switch on.

Using the screwdriver again, adjust the potentiometer that is closest to the back wall of the enclosure. See the photo for more clarity.
The output should be 6.0V.

Swap the probe to the last remaining wire. Verify that it is also at 6.0V.

Next, turn the power pack off, and disconnect the battery. Remember to properly store your batteries when they are not in use.
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Page last updated on: Fri Jan 17 21:51:24 2020