April 2019

It’s back! From this issue we revert to our original name of Practical Electronics magazine, continuing our 55 year old tradition of bringing you the best available hobby and home construction projects, theory, articles, tips and advice to enable you to enjoy the exciting world of modern microelectronics.

We’ve given the magazine a bit of a redesign but all the best features are still here as always and new columns are in the pipeline. So welcome to the first issue of Practical Electronics – jump in and see what’s on offer.

Internet-based ‘GPS’ Time Source

Here’s a clever alternative to a GPS-based clock: using a cheap Wi-Fi module to act as a time reference, its accuracy is updated via the Internet. In effect, it pretends to be a GPS unit, so any GPS clock can use it. Based on a low-cost ESP8266 Wi-Fi module with little or no assembly required.

Arduino IDE and ESP8266 files required, see article for guidance. Download the IDE from https://www.arduino.cc/en/Main/Software
The required .ino sketch file is included in our monthly download file (see above, right).

Also see this month’s feature Using Cheap Asian Electronic Modules (Part 15) which explores the ESP-01 Wi-Fi transceiver based on the ESP8266.

Infrared-sensing Heater Controller

This PIC-based power controller is suitable for basic ‘bar’ type heaters, convector heaters, ceramic heaters or oil-filled convection radiators. However due to its principle of operation it cannot be used with halogen heaters or fan-assisted heaters.

The circuit provides full solid-state control and uses a burst-firing, zero-crossing technique to minimise RFI, offering 15 stages of power control from zero to full power.  An optional thermopile offers more precise thermostatic control for more demanding applications.

WARNING MAINS VOLTAGE

High Voltages  are present throughout. This design is suitable for skilled and experienced constructors only.

Using Cheap Asian Electronic Modules (Part 15)

The ESP-01 Wi-Fi Data Transceiver is based on the ESP8266 IC which is designed to allow almost any microcontroller to connect to a Wi-Fi network. The chip responds to Hayes AT commands and can also be re-programmed to perform a variety of different tasks. This article features examines the ESP-01 with suggestions for reprogramming it or using it with an Arduino.

MIDI Ultimate Synthesiser (Part 3)

The third instalment of this DIY analogue synthesiser describes the main PCB, working on the VCA, echo, noise and headphone amp sections.  This exceptional series offers a unique and exciting opportunity to build your own quality synthesiser and it’s generously illustrated with diagrams and photographs making the project suitable for anyone who can solder neatly and methodically.

Teach-In 2019 – Powering Electronics
Part 5: SMPS Controllers

Our specially-written Teach-In series takes a detailed look at power supply techniques, and this month we explore the controller chips used in most of today’s switched-mode supplies.  Our practical project takes the form of an efficient SMPS regulator, based on some discrete components that allow you to better appreciate the principles of operation. A very useful guide on selecting equipment wire and cable is published this month as well, so that you can select the correct gauge of wire for safe operation of your circuitry.

Make it with Micromite

Please Take Note
In Part 3 (Fig. 2 on page 63) the component side of the stripboard layout incorrectly shows a track cut at position X21. The cut should not be there. The copper track view in Fig. 2 is correctly shown with no break at X21. If you have made this break, simply bridge it again with a link wire.

Also in this issue:

• The Fox Report – Barry Fox struggles with a counter-intuitive Epson printer wifi setup
• Techno Talk – phone scam warnings and how China benefits from postal tariffs
• Make it with Micromite – constructing the Micromite Development Module
• Electronics Building Blocks – make a hand-cranked LED torch with a super-capacitor pack
• Net Work – what 21st Century kids watch and why – an Ofcom report
• Audio Out – Baxandall tone control circuitry dissected
• Circuit Surgery – MOSFET power switching techniques
• PIC n’ MIX – Designing PCBs with EagleCAD (Part 2)
• Max’s Hot Beans – introducing the LogiSwitch debounce i.c.

Next month

Teach-In 2019 (Part 6): voltage multipliers and converters; Low-cost Electronic Modules (Part 16) programmable frequency module; USB Port Protector; 2x12V Battery Balancer; Frequency-controlled Switch and more.