February 2014

High-Energy Electronic Ignition System (Part 1)

This new circuit improves upon a traditional high energy electronic ignition system. It uses an IGBT ignition driver rather than the expensive Darlington transistor seen in older designs. You can use this new design to replace a failed ignition module or to upgrade a mechanical contact-breaker ignition system when restoring an older vehicle.

It suits vehicles with contact breakers, Hall effect/ Luminition sensors, optical sensors or reluctance pickups. Not suitable for magneto or CDI systems. Adjustable dwell, spark test mode, tacho output and more features make this project the cost-effective upgrade for keen auto enthusiasts. Part 1 this month outlines the principles of operation and circuitry.

Mobile Phone Ring Extender

If you’ve ever missed an important call on your mobile phone because you mislaid it or you were away for a few moments, then this Mobile Phone Loud Ringer is the answer to the problem! It detects the vibration of the phone and triggers an ultra-loud piezo ringer to let you know loud and clear that the mobile phone’s ringing.

This special design is much more reliable than trying to detect a highly-variable ring tone, especially as background sounds could cause false triggering. The sounder can be placed almost anywhere that a twin-core wire will reach. It’s the modern replacement for those old phone repeater bells.

2.5GHz 12-digit Frequency Counter with Add-on GPS Accuracy (Part 2)

World first! This superb 12 digit high-resolution frequency counter  covers a range of <10Hz to >2.5GHz. Apart from an internal timebase it also has an external timebase in put that can accept 1Hz pulses from a GPS receiver to achieve measurement accuracy approaching that of an atomic clock. Period measurement range from 1µS  to nearly 1 million seconds. 12 digit 14mm blue LED display. PIC 16F877-based.

In Part 2 of this sophisticated design, the details of constructional, setup and calibration are described. Free source .hex file available from the Library.

Surface mounted components are used. Good soldering skills are necessary to complete this project successfully.

PLEASE NOTE THAT SINCE PART ONE WAS PUBLISHED, SOME COMPONENT VALUES AND ADDITIONS HAVE BEEN MADE. PLEASE ENSURE YOU CHECK THE CIRCUIT CHANGES DESCRIBED IN PART TWO.

Teach-In 2014 Raspberry Pi (Part 5)

Our fantastic Raspberry Pi primer series continues this month by showing how the 8-channel ADC (last month) can be used with a variety of transducers to take environmental measurements. The principles of data capture for recording to e.g. a spreadsheet are also introduced. Differences in versions of Python are examined and our Pi experts dig more deeply into Python with some practical hints and tips.

Please Take Note – Teach-In 2014 Part 4

In Part 5 this month, we advised of an error in Part 4 of the January issue. In Fig. 4.13 only one diode (D2) should be shown and the second diode is not used. A corrected circuit diagram is given in Part 5.

Also this month:

• Techno Talk – developments in solar cell technology
• Max’s Cool Beans – Max makes headway in designing an Arduino-powered robot buggy
• PIC n MIX – next steps in the software design and implementation of the PIC development board.
• Interface – our PC interfacing column on the Raspberry Pi GPIO and CSI (Camera Serial Interface) connectors, and how to keep your Pi updated.
• Circuit Surgery – our in-house surgeon digs deep into the world of synchronous and asynchronous counters, with plenty of on-screen simulations to shed more light on their operation.
• Net Work – on NFC tags and how Euclid Analytics enables store owners to track physical shopper’s tracks.