Welcome

Hello everyone, welcome back to the blog, in this post I will discuss the interesting cause of my oscillation problem in the LVD circuit, and the mounting of the solar panel to the golfcart. Let's take a look!

LVD Circuit Stories, and a Lesson

When I originally built my design for a LVD circuit, I was getting an oscillation from the relays when powered, which confused me. It was actually my grandfather (who is an electrician) that pointed out something that didn't occur to me. The wires I used in some parts of the circuit would be carrying higher voltages, so I wanted to use a higher AWG wire. I currently had none, so I had the brilliant idea to use coaxial cable, but just connecting the core and the shield. (Great idea, I know.) And then the oscillation problems came. Out of desperation I brought it to my grandfather, to see if he had an idea as to what was the solution to this elusive problem. He suggested replacing the coaxial cable, as it was the only unknown in the circuit, and sure enough, the problems went away. Here's my theory: in the wire there was a plastic insulation between the shield and core of the wire, and both were connected at one end of the wire. On the other end they had come apart from a bad soldering job. (By yours's truly.) Due to internal resistance in the wire, I believe there was a small capacitor forming in the wire, which resulted in the oscillation of the relays.

As you can see in my diagram, current normal would flow from A to B, only having a small voltage drop due to the internal resistance of the wire. In my case though, there was a small attraction around connection A due to the voltage drop over the wire. As we know, capacitors are really just two plates of metal close together but separated by an insulator, with a voltage difference between them. This is an odd situation, but a good lesson as well, not to use coaxial cable as a higher gauge wire. The circuit is still not in functional order yet, as I have ordered a DPDT relay that will be arriving soon to replace the two relays I have been using.

Solar Panel Mounting

While I have been waiting for the kit to arrive, I decided to mount the solar panel onto the golfcart. My solar panel has a strange mounting bracket, forcing me to use a nut on the inside of the frame and then run a bolt to it through the top of the cart.

I started with four 1/4 inch (0.635 cm) bolts each 2.5 inches long (6.35 cm), with matching washers and lock nuts.  

I also cut four spacers that fit the unthreaded space on the bolts. I then ran the bolt through the top of the cart, through the spacer and secured it with a washer and nut. I used the second washer to support the solar panel.

I did this for all four posts for the solar panel and then placed the panel on top of them.

I then secured them with nuts on the inside of the panel. 

The cord conveniently ran down the side of the top and down to the batteries under the seat, where I plan to place the LVD circuit.

In retrospect, building a wooden frame the size of the solar panel and mounting it to that, and then using a woodscrew to attach that to the cart would have been easier, as I wouldn't have to fit my hands under the panel to place the nuts, but this is more modular, so it works out. 

Thanks for Reading!

This post was a smaller one, but it had some important parts of the process. With the solar panel installed, we are one step closer to making the upgraded cart a reality! Hope you all have a good next two weeks, I'll be back on the 21st of October, with flow charts of my ColorSound and SensorXploror code, and maybe a start on programing of the SensorXploror.