My previous blog touched on peak detect circuits. What seems simple in principle can be quite problematic if you want speed and accuracy. A diode and a capacitor makes a crude peak detect but the voltage drop of the diode makes it a poor choice so you will normally add an opamp to improve accuracy. […]
Pulse signal processing: what to watch out for
A number of systems I have developed have required the processing of pulsed analog signals. Depending on the system, one or more attributes of the signal needed to be preserved and measured such as pulse height, pulse width, pulse shape and pulse position in time. Also, you usually need some gain to boost the signal […]
The Art of Electronics
In 1980, the book “The Art of Electronics” was published, written by Paul Horowitz and Winfield Hill. For many people, myself included, it became the first book you picked up when you needed to know anything related to analog electronics. It was intended as a course textbook but became a designers reference book for many […]
What’s your type? Walk-thru of semiconductor diodes
There are quite a few different types of semiconductor diode from junction diodes, Schottky diodes, Zener diodes etc. You need to know the difference between them in order to select one. A good place to start the description of the types would be a comparison of a conventional PN junction diode and a fast recovery […]
Know your group delay and phase shifts
You may or may not have thought about group delays in your electronics signal processing chain, but it is almost certainly there. It may not matter that it is there, but you need to be aware just in case. One way in which it might affect you is if you are sampling a signal. The […]
Choosing a temperature-measurement sensing method
Temperature is a parameter that often needs measuring. It may be within an enclosure, on a PCB, remotely or even “wirelessly”. Wireless, in this case, does not necessarily mean a remote sensor communicating using radio frequencies, it can mean a pyroelectric sensor. Pyroelectric sensors are very long wavelength detectors which measure radiation in the 6-15μm […]
The neglected resistor characteristics
We often take resistors for granted. They are one of the fundamental building blocks of electronics design but are often given little thought when choosing them. You will select a value and the tolerance, and probably briefly consider the power dissipation and provided that isn’t very high you will most likely be picking all your […]
Today’s wireless power transfer
Wireless power transfer has been around for a long time. The “crystal set” or “crystal radio” over 100 years ago used the power carried in the radio signal to produce sound without any amplification or receiving circuit power source. Early spark gap transmitters also used tuned wireless power transmission. Now the circuitry is more sophisticated […]
Supercapacitors: a good fit for the right niche
“Supercapacitors” (or electric double layer capacitors) have been around for a long time. Early uses were as an alternative to rechargeable batteries for retaining memory contents in domestic equipment. They were even made to look a bit like batteries in some cases, rather than electrolytic capacitors, such as these Panasonic RG series ones: This particular […]
How to measure current
If you want to measure the current taken by some circuitry, the normal way is to use a small resistance in the circuit and measure the voltage drop across the resistor. For AC currents, you can use a current transformer, but that is a bulky approach for AC applications. For DC current, particularly where you […]
