A collection of technical articles on electronics, or subjects related to electronics. Some of these articles also appear in the "application notes" section.
Since electronics and software are becoming more and more intertwined, you may also want to look in the "embedded systems" section. There is an article on debouncing switch inputs (in software), for example.
- LED current source
This article presents a circuit for a "constant current source", for example to drive LEDs. The circuit allows the current flow to be switched on and off, with 5V TTL-logic. One way to use the on-off switching capability is to dim the LEDs with pulse-width modulation.
- A MIDI to RS232 converter
The MIDI protocol is a serial data communications protocol using on a "current loop" physical layer, and using a Baud rate of 31250 bps. This article shows the electronics needed to convert between current loop and the RS232 signal levels. The circuit can be connected directly to the RS232 port of the H0420 MP3 player. In the second part, the article covers the "software protocol" of MIDI and develops a simple script to send and receive MIDI commands.
- An RS232 "spy" cable
The RS232 norm defines a one-on-one communication link between two devices. With a special cable, though, it is possible to have a third device (a PC) "listen in" on the data —a useful trick in debugging serial protocols or for deciphering an unknown protocol.
- A voltage inverter circuit
Sometimes you need to generate a negative voltage when you only have a positive power supply. The circuit in this application note does just that. The circuit was built to drive LCDs that require a negative LC-driving voltage.
- Reel quantity estimate
A simple method to estimate the number of components left on a reel.
- Candela, Lumen, Lux: the equations
There are various measures in use for quantifying the light produced by a light source, such as a LED. This article gives a brief overview of the more important measures and how they relate.
Most recent update: A paragraph on Luminance (measured in Candela per square metre, or "Nits") is included.
- Reflow soldering profiles
With a special focus on the eC-reflow-mate from Eurocircuits, this article delves into the art and craft of creating reflow soldering profiles. Phenomenons like thermal inertia and their effects on the soldering profile.