LET'S TALK ABOUT SUPER CAPACITORS!
Thanks for looking at my instructable! This instructable will be a little bit shorter than some of my others, and it will be written from the perspective of a technician, not an engineer. This instructable will be followed with similar super capacitor related instructables. I'm not going to blast super capacitor noobies with a ton of flashy math. However, I will be providing links to sites where math can be found for those of you who are interested. I want to keep this document as practical as possible. There are some fun videos in STEP#8 and some links to my hobby electronics stores in STEP#9. For those of you who don't know much about super capacitors, here is a little bit of fun theory:
Super capacitors act like any other kind of capacitor, only they can store tremendous amounts of energy. Many capacitors that you'd have seen in audio circuits have capacitances such as 470uf or 680uf (micro farads). Capacitors used in high frequency RF applications can be as small as 1pf (pico farad). The farad is a measure of capacitance (or storage capacity). They are often used in filtering applications, coupling or decoupling applications, or AC-DC smooting applications (there are some large caps in your standard AC-DC power supply that acts to smooth out the ripple on the line).
Super capacitors can be used in solar power applications, battery back-up applications, battery applications, flash-light applications, etc. Aside from the fact that the super capacitor can be charged very quickly due to their low internal resistance, which is known as ESR, but they can just as quickly be discharged. Batteries contain harmful chemicals, and die over time. If you handle your super capacitors carefully, you will die before they do...Seriously! Howver, there are rules...
Super capacitors do not give off gas like lead acid batteries, but they cannot store as much power either. You can place capacitors in series or in parallel to either up the maximum charge voltage, or total capacitorance. We will talk about this later.
Really, there is a lot to be said about capacitors, and you're not going to want to spend your entire day listing to me, so let's get down to the basics. You can go fourth and choose which tabs you;re interested in. Here is a video just for fun of me starting my car with super capacitors!
Step 1: Understanding Capacitance
Have you ever heard someone talk about nano this or micro that? These terms can be used for voltage, power, current, resistance, inductance, etc. When we talk about the capacitance of a capacitor, we will do the same. The below explanation will also help you to understand just how much capacity a super capacitor has in relation to a standard capacitor.
Understanding Capacitance Terminology:
1pf (pico farad) = 0.000000000001 farads
1nf (nano farad) = 0.000000001 farads
1uf (micro farad) = 0.000001 farads
1mf (milli farad) = 0.001 farads
The table in the image is much more detailed. This page is an attempt to demonstrate just how much capacity a super capacitor has. A one farad super capacitor can store one million time more energy at a common voltage, than a 1uf capacitor, one billion times more than a 1nf capacitor, and one trillion times more than a 1pf capacitor. Cool, huh?
However, super capacitors have very small voltage ratings, such as 2.5v, 2.7v and 5.5v (Some common values). This makes things difficult, as in order to make our capacitors capable of charging up to a higher voltage, we need to place them in series, which brings a bunch of other variables into play. There are sections coming up on Series/Parallel configurations, as well as charging methods, and balancing methods.
You can also employ DC-DC voltage boosters. Typical DC-DC boosters take a voltage of around 3.4-5VDC and are capable of boosting the output voltage. We sell all sorts of boosters, super capacitors, and solar panels here:
Visit our ebay store here: http://www.electroniclessons.com/
Please check out our hobby electronic store here: http://engineeringshock.com/