September 2019

Intelligent Touch Screen Lathe Speed Controller

This design combines two very popular projects, the 1.5kW Induction Motor Speed Controller and Micromite Plus Explore 100 with 5” touchscreen, then adds extra circuitry to provide an easy way to control a lathe. It automatically adjusts its speed to suit the material being turned, provides a constant display of the lathe’s status and allows its speed and direction to be selected. A very worthwhile upgrade that puts digital lathe control in the hands of the home machinist. Details of modifications for 3-phase control are also included.

Super-Portable Twin Dipole Guitar/ PA Speaker

This guitar/ PA speaker is easy to build and really portable. It’s also LOUD and sounds great!  When on stage, you can project plenty of sound to the crowd while still being able to hear your own playing (no foldbacks needed). If you build it using our recommended 12” Celestion drivers (as used by Hendrix and Slash) it has a mellow, vintage tone. Different drivers can be used for a more modern, harder sound.

Using Cheap Asian Electronic Modules (Part 19)  – Arduino NFC Shield

This low-cost NFC shield uses the same technology as contactless payments and allows just about any Arduino board to read data from NFC/ RFID tags and cards, exchange data with many smartphones or write data to certain devices.

Super Digital Sound Effects Module (Part 2)

Whatever sound effect you need, of whatever duration, for whatever purpose, this tiny powerhouse will amaze you with its capabilities. Its compact size makes it great for toys, model trains, greetings cards, vending machines, exhibitions and lots more besides. It can be loaded with dozens of .wav sound effects, audio tracks lasting from fractions of a second to hours, and it boasts virtually unlimited playback time and advanced controls.

In Part Two this month, construction and programming are described.

 Surface mount components are used throughout. Good soldering skills are needed to complete this project successfully.

White Noise Generator

This white noise generator is very simple and cheap to build, producing white noise digitally with a PIC12F617 using a pseudo-random EXOR technique. It does not repeat itself over any short time frame and its uses include sleeping aids, tinnitus masking, PA setup testing and analogue synth sounds.

Electronic Building Blocks

Quick and easy construction on a low budget – trying several cheap and cheerful LED clocks available online.

Practically Speaking (NEW)

This month sees the welcome return of an old ‘EPE’ and ‘ETI’ regular series covering practical workshop techniques. It will offer plenty of hands-on practical hints and tips for the constructor, starting this month with soldering irons, component testers and adhesives.

Also in this issue:

• Techno Talk – ‘Repair Cafés’ are the new trend in community repair shops
• Net Work – Britain’s ambitious green energy plans, and the rise of electric vehicles
• Circuit Surgery – Understanding bipolar junction transistors (Part 3)
• Audio Out – Designing Hi-Fi Mini-monitor loudspeakers (Part 1)
• Make It With Micromite – Dice Prediction Game and Mini MKC Clock
• Max’s Cool Beans – Discussing flipping and flopping – metastability

Next month

Opto-isolated mains relay; GPS-synced Frequency Reference; DCC programmer for model railroads; Audio Out LS3/5A monitor speakers and more.