Tutorial: Electrical impedance made easy - Part 2

This is the second video of a short series in which I discuss the basics of electrical impedance from a practical standpoint. In this video, I explain the importance of knowing the magnitude and angle of impedance, as well as how this affects the power factor of a given electrical circuit.

Tutorial: Electrical impedance made easy - Part 1

This is the first video of a short series in which I discuss the basics of electrical impedance from a practical standpoint.

In this video, I show how a simple LED power supply circuit can be made more efficient by replacing a resistor with a capacitor. I describe the difference between resistance, reactance, and impedance.

DIY Scanning Electron Microscope - Operation procedure

After getting back from Maker Faire (which is always a hugely enjoyable and inspiring event), I thought that my microscope might need some repairs. As it turned out, I only had to change the filament and tighten some screws that came loose during the trip back from the Faire. The microscope works just as well as it ever has -- I didn't even need to move my alignment magnets. I made this video to show everyone what using it is really like.

Also, if you haven't been able to attend Maker Faire yet, it really is as amazing and epic as you have heard. The intelligent and inspiring people who make it happen are a large part of the motivation that I had to build and display this microscope. In turn, I hope my project inspires others to create things and share their ideas with everyone. There's no better way to have fun and celebrate accomplishment at the same time!

Product Review: Grizzly 4003G metal gunsmith lathe

I recently bought a Grizzly 4003G lathe, which has proven to be a very useful tool in my shop and a major upgrade from my previous lathe. The 4003G is a great value, and I would definitely recommend it for anyone looking for a 12x36 lathe for hobby or semi-pro work.

Shop lighting upgrade: T5 vs T8 fluorescent vs LED

I am in the process of upgrading the lighting in my shop. It currently has a number of 4-lamp and 2-lamp T12 4-foot fluorescent fixtures. The best solution is to replace the ballast in each of these fixtures with high-efficiency electronic ballast ($15), and replace the lamps with T8 high-CRI bulbs. This will save energy, and greatly improve the quality of the light. LEDs and T5 fluorescent are MUCH more expensive to install, and their energy savings are not nearly enough to justify the cost. Most LED systems actually use more energy than T5 or T8. Remember that running a T8 with an electronic ballast will provide more light than it's nominal rating, which is for magnetic ballasts. T5 are always rated for electronic ballasts, so it is not a fair comparison.

For new fixtures in my shop, the cheapest/best solution is to buy $10 "shop lights" and replace the ballast. The total fixture cost is $25, and efficiency is 96 lumens/watt for a total output of almost 6000 lumens. It can't be beat! Commercially-available T8 fixtures with electronic ballasts are more expensive, and the quality of the ballast is suspect.