Nikola Tesla by Napoleon Sarony. Via Wikipedia Commons.

Nikola Tesla is one of the more unsung inventors in American history. That's despite the fact that he's largely responsible for the discovery that led to the widespread usage of alternating currents, or AC, as the backbone electricity transmission system. It's a system that's still used today to power modern society.

However, as important as that breakthrough has been, he made a number of other important discoveries that we also tend to forget about. That's largely due to the fact that he never received full credit for some of his inventions due, in part, to timing. Here are three of his revolutionary ideas that we forget he was the first to discover. 

1. X-ray technology
In 1884, Nikola Tesla started looking into what he called "radiant energy of invisible kinds" after noticing damaged film in his labs that were associated with some experiments he was undertaking with a Crookes tube. Through that process, he is believed to have inadvertently captured an X-ray image a few weeks before Wilhem Rontgen's announcement of the discovery of an X-ray in late December of 1895.

Because the discoveries were made so close together, Tesla never pushed for his discovery to be the preeminent one. Instead, upon hearing of Wilhelm Rontgen's discovery of the x-ray and x-ray imaging, Telsa proceeded with his own experiments with x-ray imaging to improve upon the process.

2. The radio
Nikola Tesla first demonstrated that radio signals were just another frequency that needed a transmitter and receiver in 1893 at a presentation before the National Electric Light Association. Then, in 1897, he applied for his first two patents surrounding that technology, which were granted in 1900. However, in 1904, the patent office reversed its decision, and instead awarded the patent for the invention of the radio to Guglielmo Marconi, who famously made the first transatlantic radio transmission in 1901.

Tesla never fought him over the issue, instead saying: "Marconi is a good fellow. Let him continue. He is using 17 of my patents." It wasn't until 1943 that the U.S. Supreme Court overturned Marconi's patent after it was proven that Tesla was the one who had indeed invented the radio already.

3. The remote control
Through his work on radio signals, Tesla also invented the first remote control, which he demonstrated in 1898. He used batteries and radio signal-controlled switches to remotely control a model boat. The invention, which Tesla dubbed "teleautomaton," was first demonstrated at an electrical exhibition at Madison Square Garden. It wowed the crowd; those in attendance were dumbfounded, claiming it was magic, telepathy, or that Tesla had little trained monkeys inside the boat to control it.

Even though he often doesn't get the credit he deserves, Nikola Tesla invented several of the technologies we take for granted today. One of the reasons he was so successful was because he focused his attention on one area to really understand how it truly works, which, in his case, was the unseen electrical waves all around us. In so doing, he was able to harness their power so they could be put to greater use by mankind. If it wasn't for his unrelenting focus, the world today might be vastly different.

The other key takeaway is that timing really can be everything. That's important not just for inventors, but for investors. Those who invest in new technologies before anyone else has discovered their potential will reap much bigger rewards than those who show up even a little bit later.