RC car motor question

Tech Talk
1

I’ve got a small cheap RC car that I’m currently working on for my senior design project with my group. It’s only controlled by 2 small motors (not sure of the size) one that controls the left to right turning of the front wheels and the other that controls the forward and reverse motion of the car. The problem is that either the forward or reverse motion of the car is either zero or it’s wide open going full throttle.

I’m trying to make a BJT circuit that can supply the minimum 200 mA necessary to drive the motor, but can control the speed by adjusting the duty cycle, as in a 50% duty cycle would go half as fast as full speed. I’m attempting to use a voltage divider bias configuration with AC feedback filtration. Any help or suggestions would be greatly appreciated. If you need any additional info feel free to ask.

2

Wow, my final year project is also about RC cars. Although ours is about controlling the car instead of how the car functions.

However, with that said, we’re planning on the same thing. While we haven’t actually implemented it yet, we’ve bought servos to replace the motors on our RC cars. Unless your project is about designing and making a current sensing circuit, a servo should do what you want.

3

Our final project goal is to make the car autonomous and parallel park itself, but it’s one step at a time. It’s a lot easier for our project to just use the existing motors, so we don’t have to manufacture a new gear system to work with them.