Thirty years ago remote control toys meant a disappointing car that could barely get out of its own way. The advertising and pictures always exaggerated the toy’s capabilities and made it look like it could do the impossible. Adding insult to injury, those toys were $50.00 then.
Somehow I ended up with three drone quadcopters this year. One from my daughters, one from my brother and one, well, that I bought myself. I was expecting to be thwarted yet again by artistry and descriptions that seem almost too good to be true. After hours of flying I can tell you they really work.
I immediately questioned how anyone can make a $50.00 toy that really flies and takes video. I understand China is knocking out gazillions, but a toy that flies still seems fictitious. After pondering how they work I decided to take one apart.
Interestingly the wireless technology used is the same as the last generation wireless routers. A 2.4GHz signal is transmitted between the handheld remote and drone allowing some in-flight feedback. Although pretty minimal on inexpensive drones, I get reported on battery life and angle. More expensive drones provide much more feedback.
Four little motors are reduced in speed through a transmission which connects directly to the propellers. Although each motor spins at the same speed, two opposing motors rotate opposite of the others. My understanding of the reasoning behind opposing motor rotation is to make controlling the copter easier.
My little quadcopter has motors with two wires while more expensive drones have three wires from the motor. Prop speed is controlled by changing the voltage to each motor through the controller which on mine simply increases the speed. Expensive drones utilize a third wire which provides feedback on motor speed to the controller board.
Special lithium polymer (LiPo) batteries are used in these little toys. In reality the technology behind the batteries is the same as those used in many cell phones and tablets. What sets LiPo batteries apart from others is they are somewhat flexible and tend to be much lighter in weight than other battery technologies.
One crazy thing I noticed when taking apart my drone was the lack of overcharging circuitry. Laptops and other devices have come equipped with limiting circuitry for years so I was surprised not to see something similar in my toy. If you plan to buy a drone or already own one, you should be cognizant of this and not leave charging batteries unattended.
With a little digging I figured out how drones control pitch and angle. During takeoff they need to be on a flat surface suggesting there is some type of gyroscope. In reality I found an accelerometer which is basically a ball that floats inside cup reporting angular acceleration. Most cell phones also come equipped with such a device.
Signals from the user combined with those from the accelerometer are processed through a small microprocessor that compensates for light wind and other variables. Within milliseconds after receiving a signal from the remote, the processor calculates which of the four motors will be accelerated to maintain the angle and desired speed.
Surprisingly there’s a ton of technology packed in these little toys. If you’re considering buying one for fun I wouldn’t suggest spending a lot of money. I would suggest doing some research on popular brands and models and when you place your order also consider extra propellers, motors and batteries. I found it handy to also keep a forty foot ladder at the ready.
(Jeromy Patriquin is the President of Laptop & Computer Repair, Inc. located at 509 Main St. in Gardner. You can call him at (978) 919-8059 or visit www.LocalComputerWiz.com.)