Engineering has become a global process. A discovery made in a Munich university lab can spawn dozens of projects throughout Europe that ultimately inspire a disruptive new product manufactured in Texas. To acknowledge this tradition of engineering evolution and innovation, and as part of our Elektor 60 celebration, we are regularly spotlighting at stand-out electronics articles, DIY projects, and engineering tutorials from the past. We trust that the following articles from previous August editions will inspire you to develop new projects and solutions.

Elektor SDR Reloaded (2016)

Software Defined Radio (SDR) is a hot topic in our community, which is why we’ve been writing about it for years and we are sell popular books and bundles on the subject. In the 2016 article “SDR Reloaded,” you learn that SDR can also be used for making measurements. The receiver’s characteristics are defined in software, which gives you the opportunity to use an Arduino Shield as a front-end. 
 
SDR reloaded

It's technical characteristics include:
 
  • Supply voltage: 5 V and 3.3 V as for Arduino
  • Frequency range: 150 kHz up to 30 MHz
  • Sensitivity: 1 μV
  • Total amplification: 40 dB
  • Maximum antenna signal level: 10 mV
  • Dynamic range: 80 dB

Author Burkhard Kainka writes: "Why not simply build the entire receiver as an Arduino Shield? This decided the power supply requirements, using the USB interface already available on the PC. The Arduino would look after controlling the VFO and could be addressed in plain language so to speak (6030 kHz please). And what is perhaps even more exciting, this even gives you a real chance to build a totally standalone receiver. Operation could be migrated from the PC to the Arduino relatively simply. And who knows, perhaps one day the decoding of the IQ signal as well?"  Read More

Easy Home Remote Control (2006)

Interested in home control and automation solutions? Carlos Ferreira one for the lazy? In August 2006, he wrote that his Microchip PIC-based circuit was designed for "maximum indolence in front of the telly." Basically, the design enabled him to control a variety of devices (e.g., ceiling lights, floor lamps, and window curtains) with his handy TV remote. 
 
Home remote control

"The software developed for the project is stored in the PIC microcontroller. It allows four different RC5 codes to be saved and used to control the four outputs. For example, your TV remote may be able to control five systems: TV (default), VCR, DVD, AMP, SAT. If, for example, you do not have VCR then the relevant IR codes are available for Easy Home Control. If your remote control is not compatible with RC5 codes, you can buy a cheap universal remote control to do the job." Read more

Car Battery Monitor (1994)

Over the years, Elektor has published crazy projects, as well as practical ones. This car batter monitor falls into the latter category. After describing the discharge behavior of a lead-acid battery, K. Walraven presents a handy circuit that measures the discharge level of the car battery by monitoring the battery voltage. "If the voltage is in danger of becomming too low for the car to be started, the extra loads (lights, radio, etc.) are disconnected from the battery. So, if you happen to have forgotten to switch off something, that will not cause a lotally drained battery." 
 
Battery monitor project

The battery saver is based on the familiar 723 voltage regulator, which contains a stable 7.15-V reference and an op-amp. While this isn't the only batter monitor ever covered in Elektor, it is definitely is one you shouldn't miss. Read more

Solar Power Generation (1987)

One of Elektor's most popular articles this month is Dr. Thomas Scherer's "DIY Solar PV Installation: Building a Balcony Power Plant." But did you know that Elektor has been covering solar power solutions for well over 30 years? Back in August 1987, Elektor published an in-depth article titled "Solar Power Generation," which covered many of the foundational concepts on which today's solar technologies are built: solar collectors, MHD generators, solar cells, silicon solar cell operation, and more.  Read more
 
Digagrams from the solar power generator article.

555 as a Trigger (1975)

The 555 is a classic that has been featured in Elektor hundreds of times. In August 1975, Elektor covered the 555 as a trigger. "The IC 555 is normally used as a timer. The time delay for these applications is obtained by charging and discharging a capacitor between two well-defined voltage limits. For this purpose the IC has two voltage-sensitive inputs, which can be used in a trigger circuit." 
555 as a trigger
FYI: In very near future, we will publish a new article titled "Fifty Years of the 555 Timer IC," so keep an eye out for it.

More Engineering to Come

Stay tuned for more classic Elektor electronics projects and tutorials. Next time, we'll highlight some of our editorial team's favorite articles from past Septembers. The engineering never stops. Take out an Elektor membership if you haven't already. Why wait?