Like the takeoff and landing phases for aircraft, the startup and shutdown phases for a power supply can be critical. Control logic must be in the correct state before power is applied to high-power switching components. We had this driven … Read More
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The Single Channel Oscilloscope?
We’ve recently seen a number of announcements for single channel digital oscilloscopes. Some are configured like a (very large) pen. This is convenient, but the single channel is a real limitation. A single channel scope can display one signal, so it can … Read More
Curing Circuit Oscillation
You have built some clever analog circuit and now, when you go to check it with an oscilloscope, you find that the output signal is a mess: not what you expected, but a mass of oscillation riding on the output … Read More
Testing a Selenium Rectifier
Before the invention of the silicon diode, designers had the choice of germanium point contact diodes for low currents, copper-oxide rectifiers in instruments, and selenium rectifiers for power applications. The selenium rectifier replaced the vacuum tube rectifier in … Read More
Testing IGBTs
We were asked the other day whether our curve tracer CTR-101 can test IGBT devices. What’s an Insulated Gate Bipolar Tranistor (IGBT)? If you live in a world of small analog signals (that’s us), then you probably haven’t used an … Read More
Analog Design Not Dead
I’m not much of a party person but there are occasions when one’s presence is required – and some parties can even be fun if you keep an open mind about it. (Just beware of an open bar on an … Read More
Negative Tracking Power Supply
It is not uncommon for a circuit to have available a positive power supply, but require a negative supply. For example, using op-amps to process an alternating voltage signal (one that goes both positive and negative) may require a negative … Read More
On Power Supplies
Are you starting to learn electronics? A power supply is an excellent starter project: the basics are very straightforward, and a power supply is reasonable to built and troubleshoot. Even better, as your skills advance, there are some interesting – … Read More
Integrating Sphere for Luminance Calibration
One of our projects is to measure the luminance (brightness) of various sources of light pollution, using a digital camera. To do that, you need a calibrated source of luminance. It turns out that a low-cost purpose-made light integrating sphere … Read More
Syscomp Software on the Raspberry Pi 2
Recently, we have been evaluating the Raspberry Pi 2 computer. For those who have been visiting a distant part of the galaxy for the last few months, the Raspberry Pi 2 (RP-2) is a single-board computer, about the size of … Read More