BIG
DIGIT display — intended for use with a particular type
of surplus electro-mechanical seven-segment display (provided courtesy of
Display Electronics - and British
Rai!l), we offer a PIC-based controller for these 10" high digits with
control software that runs on a PC. Drives one to eight digits (expandable
upto 64 digits), they can be controlled by a 4 × 4 keypad or via a
standalone PC program written in QBasic.
Teach-In
2002 - our ten part series on environmental measurement systems, sensors
and design techniques looks at noise, comparators and digital optical sensing,
with the application of a wind speed detector being examined. Our practical
Lab Work experiments gives details of an optical wind direction sensor and
an optical anemometer. 
Washing
Ready Indicator - uses a vibration sensor to detect when the washing
machine has finished its cycle. Self contained and battery operated, an
ideal project for beginners.
In June
2002's issue (P. 431) we stated that the quad op.amp ICL7642 had been
discontinued. The LMC60441N is pin for pin compatible.
PIC™ Freezer Alarm - helps prevent food from defrosting unexpectedly. Uses the Watchdog Timer capability of the extraordinarily versatile 8-pin PIC 12C508, free source code available from our FTP site.
Simple
Audio Circuits (Part 1) - a super new series describing audio amplifier
circuits, starting with the principles of power amplifiers. We offer no
less than six amplifier designs this month, based on a variety of popular
audio amplifier i.c. chips including LM380, LM386 and TDA2003. Make sure
you check the rest of the series as well!
Net Work
- The Internet Column - our webmaster suggests more stripboard designer
and front panel software that you can download from the Internet.
Also in this issue: New Technology Update shows how dye molecules improve solar efficiency. Practically Speaking gives constructors a general look at enclosures for your projects; Circuit Surgery examines analogue opto couplers. Ingenuity Unlimited offers more readers' own circuits.