Power Wheels : Electronics

Power Wheels : Electronics

Nov 21, 2022

Nicholas Cordero

Alongside the mechanical aspects of building a go kart, come the tedious challenges of wiring everything up correctly. Making sure everything is getting proper voltage, nothing more and nothing less, ensures that our kart will function just the way we want to. Anything receiving too much voltage can result in electronics getting damaged and will cause more trouble down the road. Likewise, anything receiving too little voltage will result in insufficient power, making our electronics not work the way they’re supposed to. 


When I first joined the Boca Bearing team, I noticed that our throttle had one slight problem. When connected to the controller and battery to control the motor, the throttle worked even though it was turned off which should not be the case. When turned to the on position, it should receive the power it needs to control the motor and when off, it should cut off power so that it doesn’t control the motor. Another thing is that the throttle also has a voltage meter on it which wasn’t working at the time. 



This smaller red wire was originally connected to the bigger red wire, which is a constant 48 volts to the throttle, allowing it to work even when turned off. To fix this problem, we have to refer to the controller wiring diagram to see which wires do what and eventually I found the one needed to control the throttle. 



The blue wire from the throttle needed to be connected to the smaller red wire that was shown earlier to allow the throttle to turn on and off, and the yellow wire from the throttle needed to be connected to a power source. Fixing this problem was a huge plus as it saves us from worrying about the go kart moving when it's not supposed to. 



Another problem I encountered, though not as huge as the other, was the kill switch wiring.




As seen in the pictures, we can see that the kill switch had 2 noticeable problems: 1) the wiring is too short and 2) the ends of the kill switch are not compatible with the controller ends. A simple fix to both of these problems is just to increase the wiring and solder the new ends on the kill switch to allow it to connect to the controller. 



With this being fixed, we can now comfortably connect the battery to the kill switch and then to the controller. 



Following the Power Racing Series rules and regulations, the following are installed to our 48v battery: a motor and controller, throttle, low voltage alarm, kill switch, and a horn. That being said, not all of these items listed can take a 48v rating as it will destroy them. To attack this problem, we used a 48v to 12v step down transformer so that we can give 12 volts to the necessary electronics to function properly. 



The gray block off to the left is the controller, which takes a 48 volts input and outputs 12 volts, which is connected to the rest of the electronics including the horn and button, and then eventually to our motor. 



At the time of writing this, we have yet to install the fuse and transponder as we wait for more parts to come in, but the electronics portion of the go kart is coming together very well and is close to being complete. Although everything is messy now, we would like to keep it this way until it is time to install it in the go kart, where we then can clean it all up using some wiring sheathing and shrink wrap to make it look more tidy and professional.