Click the image at left or any of the images below to be redirected to my CafePress store to purchase individual or a complete set of electrical warning signs. These signs are appropriate for an Enphase microinverter-based grid-tie PV solar system. The signs are printed on UV and weather resistant 4-mil vinyl stickers. The complete
The voltage regulator built onto the Arduino Uno is a linear-type regulator and is horribly inefficient. If you are running the ATmega238 at 5V using a 9 V battery, approximately half of the battery’s energy will be dissipated as heat by the regulator. This post demonstrates a DC/DC switching-type voltage regulator circuit that can be
As a physics professor, I’ve discovered that the biggest impediment to success in college physics is a shaky foundation in high-school level algebra. If you are unsure of your algebra ability or want to review key concepts in preparation for physics, this page is for you. Let’s review: Order of Operations Consider the following mathematic
A bipolar junction transistor (either PNP or NPN type) can be used as an analog amplifier or as a digital switch. These days, it is probably much simpler to use an operational amplifier to achieve amplification of analog signals instead of building an amplifier using individual transistors but there are many situations where using a
When I installed a Enphase microinverter based ground-mount PV system for my home, I had to be keenly aware of the voltage drop (really voltage rise) from my array to my main load center. My array is in my back yard, approximately 150 feet from my load center. A run of wire this long will