November 2017

50A Battery Charger Controller

Designed with motorhome and camping enthusiasts in mind, this heavy duty charger controller is designed to provide a very fast charge to 12V or 24V ‘house’ batteries using either a 230V petrol generator or solar panels.

It means batteries can be charged in a fraction of the time, using less petrol and creating less disturbance too.  Our design offers up to 50A with adjustable voltage, and optionally it can power down the generator automatically via a ‘kill switch’ when charging is complete (modification details are included).  PIC 12F675, with hex file downloadable from our Library.

Micropower LED Flasher

A modern PIC-micro powered replacement for National Semiconductor’s much-missed LM3909 LED flasher i.c., this microcontroller design also adds an optional l.d.r.  to provide daylight detection, and can flash any colour LED (modification chart included). A key feature is its tiny quiescent current, typically 10µA at 5V supply. 12V operation possible with simple modifications.

Two versions are provided, a larger one with CR2032 coin cell holder and a tiny one (36 x 13mm!) to incorporate into model railroads, toys etc. Hex file available for download from our Library.

Phono Input Converter

A simple passive converter circuit that lets you use the phono inputs on an amp or mixer, normally dedicated to turntable use, as a pair of line-level inputs instead. You can then connect another CD or DVD player or other line-level program source.

Easy to build, both through-hole and surface-mount versions are described.

Micromite Plus Advanced Programming (Part 1)

The Micromite Plus is not only faster than the Micromite, but also boasts more RAM and storage space, SD card support and a GUI application library.

Thus the Micromite Plus makes it easier than ever to develop powerful, graphically rich and interactive touchscreen-based controllers.

In Part One this month, programming basics, controls and SD card functions are described. The Micromite Plus  runs natively in BASIC and is simple, interactive and fun. Try it now!

You can also see a Youtube video introducing the features of the Micromite Plus.

Teach-In 2018 – Get Testing!
Part 2: Oscilloscopes

‘Scopes are an indispensable test and measurement aid for analysing what’s going on in electronic circuitry.  A bewildering choice of features is available including basic CRT (cathode-ray tube) types, digital storage scopes and USB scopes in a price band that stretches from £50 to £5,000.

This part of Teach-In describes in depth all the basic operating and usage principles of oscilloscopes and how to use them in typical testing routines. A simple ‘scope calibrator is offered as a constructional project. Don’t miss out on our monthly series – get testing now!

Electronic Building Blocks
High Current Battery Charger

Electronic Building Blocks uses cheap and cheerful modules or spares to make something interesting and worthwhile – and cheap, too! This month we describe a quick ‘n easy 35A charger for go-cart batteries, 12V/ 24V truck batteries and similar, made out of an old arc-welder transformer.

Also in this issue:

• Net Work – the Internet column suggests two indispensable apps for sharing content on your network
• Techno Talk looks at the way mobile phone masts are evolving to blend in with the countryside – sometimes anyway!
• PIC n’ MIX – for PIC micro users, the MPLAB X IDE, Microchip’s plugins and Code Generator
• Circuit Surgery – more ideas for temperature sensors, and the thermocouple (Part 2)
• Audio Out – MX50 power amplifier circuit tweaks (Part 1).
• Max’s Hot Beans – some gorgeous Nixie tubes and an LED-based  ‘Lixie’ display, and Max’s latest vintage acquisition: a phone dialler!

Next month

Digital Theremin using Arduino; Precision Voltage and Current Reference with Touchscreen Control (Part 2); The Micromite Plus LCD BackPack; Micromite Plus Advanced Programming (Part 2; Teach-In 2018 (Part 3).