Twinkling
Lights - our beautiful 4-channel lighting effect will brighten your
Christmas tree or party displays. Uses a straightforward 4000 CMOS circuit,
with solid state triac outputs for reliability and quiet operation.
Ghost
Buster - This device is based on the principle that some reported sightings
of ghosts have actually been attributed to the presence of low frequency
resonance caused by standing waves, which create a "spooky" and
creepy feeling in the atmosphere. Our design has a bargraph display and
includes a DIY low frequency microphone design. Interesting in its own right,
every ghost-hunting team should have one. Also useful for environmental
monitoring.
PIC Polywhatsit
- we couldn't decide a name for this project - suffice it to say that
this highly versatile musical effects unit offers you all the most popular
delay-based effects in one. Echo, Reverb, Delay, Flange, Phasing, Vibrato,
Pitch multiply and more, all combined into one PIC-powered project! The
source code for the PIC microcontroller is available free from our FTP
site, so you can program your own chip, or experiment with the code if
desired.
In the Feb.
2002 issue (P.116) a correction was published. Page 870, Fig. 2. The "ring"
of the output socket SK2 should be connected to the 0V rail and not Vref.
Wiring diagram Fig. 5 is correct.
Mains Failure
Alarm - an easy to build device designed for aquarium owners, also
if you have a deep freezer you'll want to build this alarm unit that warns
of power loss. Uses a small "aerial" (antenna) wire wrapped
around the mains lead to monitor power seamlessly.
In the Feb.
2002 issue (P.116) a correction was published. Page 839, Fig. 2. A small
supply link wire is missing from point A17 down to B17 on the stripboard.
This is of course needed to power IC1 at pin 14.
Also in this issue: New Technology Update - a brief history of l.e.d.s and how they could finally replace incandescent lamps; Ingenuity Unlimited - readers' own circuits; Interface (PC Interfacing ideas) looks at simple A/D conversion using a 12 bit chip; Net Work examines some popular shopping carts. Circuit Surgery explains the basics of different types of op.amps, concentrating on the transconductance amplifier. Marconi, the father of Radio - this being the 100th anniversary of the first transatlantic radio transmission, we celebrate the work of Guglielmo Marconi, often called the father of Radio. Our special feature looks at the man behind this momentous achievement.