Uses a small d.c. electric motor with a winding handle to charge up a 1 Farad capacitor for its energy source. Simple a.m. radio receiver circuit drives a crystal earpiece. Fun and interesting to build.
Versatile
Event CounterThis PIC-powered project has a multitude of uses as a counter, frequency meter (< 20kHz), and elapsed time in a variety of modes. The highly versatile design can accept audio signals via an electret microphone if desired. Displays elapsed time, total event counts, average rate; counts per second, minute or hour as desired. Liquid crystal display readout, battery operation. Source code available free from the EPE FTP site here. A useful piece of gear with a multitude of uses.
Ironing
Board Saver
Detects when the iron is not in use, by using a simple vibration sensor.
Delayed action prevents power wastage when the iron is not in use.
Introducing PIC 16F87x Microcontrollers<
EPE's Technical Editor John Becker describes Microchip's new enhanced
EEPROM PICs, which have even more to offer than the hugely popular 16C84
microcontrollers that are transforming electronic project-building. PIC
users everywhere must read this update!
Voice Record/
Playback Module
Less cuddly than a Furby (remember those?), but more useful! This is your
very own personal voice box, which digitally records up to 16 seconds
of sound from the built-in electret microphone. Uses an ISD voice chip.
Easy and fun to build.
MAX761 d.c. to d.c. converter
Andy Flind describes some applications of Maxim's step-up voltage
regulator chip, offering circuits and fundamental design notes.
PhizzyB
Computers 6 It's time to add "feelers" to our PhizzyBot
computer-controlled motorised platform, in the latest chapter of our world-exclusive
series. Next month, PhizzyBot acquires "eyes" and can move towards
a light source.
Please note,
the PhizzyB hardware is now almost obsolete, with few kits or MCU chips
remaining. Please check all parts are available before commencing construction.
Also in this issue - Circuit Surgery looks at solid state relays and photovoltaic relays; Net Work checks out the UKs latest free ISPs; Ingenuity Unlimited - Readout - New Technology Update.