Intruder
Alarm Control Panel - our 5-zone professional-standard controller
forms the heart of a security system compliant with British Standard BS4737.
Has exit/ entry delays, auto reset, bell shut off, walk test and many
other options. Separate bell module also described.
In the June
2001 issue (P.431) we published corrections as follows. Page 357 Fig 5:
unfortunately the main p.c.b. component layout shows some of the diodes
incorrectly annotated. They should be as follows: D5 becomes D22; D6 becomes
D11; D7 becomes D12; D8 becomes D6; D9 is ok; D10 becomes D8; D11 becomes
D10 and D12 becomes D5; D22 becomes D7. The circuit and components list
are correct. The author also adds that the battery for the extension bellunit
mayb e any voltage between 7.2V and 12V, rated approx 250mAh, Ni-cad or
sealed lead-acid.
Snug
Bug Controller - A 4-channel personal "central heating" system
for your tropical pets. Up to four thermostatically controlled dry heat
pads can be used, for snakes, toads, lizards and other reptiles.
Wave
Sound Effect - Bring the relaxing sound of the sea into your home! Use
our electronically-created "sea sound" to mask annoying background
noises. Uses a near-"pink" noise circuit to produce gentle, soothing
effects similar to the sound of gentle rainfall. Battery powered, headphone
operation.
Sound Trigger
- another "Top Tenner" project that can be built for about ten
pounds ($7). This battery-powered project lights a small bulb when sound
is detected by the built-in microphone. Instructive, economical and safe,
this project is ideal for younger constructors or beginners.
The SchmittTtrigger: Part 6 of our In-Depth Designer's Guide related to Schmitt applications
Also in this issue - FREE SUPPLEMENT - An End to all Disease. Can disease be cured electronically? Read our story of electronics, blackmail, intimidation, theft, bribery and even murder! Also in this issue - New Technology Update - 3D LCDs become reality. Ingenuity Unlimited (readers' own circuits), Practically Speaking (construction tips), Circuit Surgery (phase-locked loops explained).