Eye Current

Capacitor Powered Powertools

Capacitors are being looked at closely as part of our energy solutions. NASA Tech Briefs mentions a project, where they connect up a half dozen ultra-capacitors and used the caps to power their electric drill. The list of potential benefits are multitude among those listed are:

1. Fast recharge times seconds vs hours
   
2. excelent cold temperature performance,
3. Low restance to discharge High currents
4. Reliability in in Milions of Charge/Discharge cycles vs 300 to thousand on batteries
5. Simplified charging circuits
6. Environmentally friendly. The long life expectancy and the lack of heavy metal make end of life issues greener.
7. Capacitors don't mind being discharged and stored for long periods of times like batteries.
8. Efficiency Batteries run at about 50% efficiecy for ther charge discharge cycles. Capacitors at around 50%

Ultra Caps haven't reached the Energy per time ratios that are achieved with modern batteries. Something like the electric drill though it might not matter if one conciders it only takes a few seconds to get a complete charge.

For the cordless drill, a dedicated charger is used to fully realize the advantages of the ultracapacitors as energystorage devices. Because of the non-critical nature of charging and discharging of ultracapacitors, this charger is less complex and less costly than would be a battery charger for the same power drill. More spectacularly, taking advantage of the unique charging characteristics of ultracapacitors, this charger can make the ultracapacitor-powered cordless drill ready for operation in seconds, in contradistinction to the several hours needed to recharge batteries.

There have been a few potential breakthroughs in ultra capacitor science in the past few months. The newer technologies promise more power and energy storage for a given weight and volume. that might gain the energy vs mass ratios. EESTOR has received some investment capital and has created some industry excitement with their claims.

Ultracapacitors have advantages over traditional electrochemical batteries. Unlike batteries, ultracapacitors can completely absorb and release a charge at high rates and in a virtually endless cycle with little degradation.

Where they’re weak, however, is with energy storage. Compared with lithium-ion batteries, high-end ultracapacitors on the market today store 25 times less energy per pound.

This is why ultracapacitors, with their ability to release quick jolts of electricity and to absorb this energy just as fast, are perfect as a complement to batteries or fuel cells in electric-drive vehicles. The power burst that ultracapacitors provide can assist with stop-start acceleration, and the energy is more efficiently recaptured through regenerative braking.EEStor ’s system, called an Electrical Energy Storage Unit (EESU), is based on an ultracapacitor architecture that appears to escape the traditional limitations of such devices. The company has developed a ceramic ultracapacitor with abarium-titanate dielectric, or insulator, that can achieve an exceptionally high specific energy—the amount of energy in a given unit of mass.

The company’s system claims a specific energy of about 280 watt hours per kilogram, compared with around 120 watt hours per kilogram for lithium-ion and 32 watt hours per kilogram for lead-acid gel batteries. This leads to new possibilities for electric vehicles and other applications, including for the military.

The trick is to modify the composition of the barium-titanate powders to allow for a thousand fold increase in ultracapacitor voltage in the range of 1,200 to 3,500 volts, and possibly much higher.

EEStor claims, using an automated production line and existing power electronics, it will initially build a 15-kilowatt-hour energy-storage system for a small electric car weighing less than 100 pounds, and with a 200-mile driving range. The vehicle, the company said, will be able to recharge in less than 10 minutes.

Its not clear what the future holds for what most technician consider a most humble component. But what isn't clear yet is just how these super capacitors are going to effect the way we do things with our control circuitry. We can count on these caps making our circuits more reliable and able to withstand almost any power blip, What could prove interesting though new ways to transfer and use the large amounts of capacitive power that will become available to us.

posted by Ray L. @ 1:08 PM