LED
Stroboscope- another EPE low cost starter project, safe battery operation. Use to "freeze" the motion of moving machines etc., this easy to build project is ideal for novices. Uses an oscillator and power transistor to deliver high-intensity pulses to a pair of external LEDs - no Xenon tube required!
12V Battery
Tester - build this hand-held probe which gives an instant "health
check" on lead acid batteries. Provides a visual indication on a
row of LEDs, of the battery's state of charge. Great for motorists and
other users.
Practical Oscillator Designs - a major new series which is intensely practical, written specially for experimenters and hobbyists. Tried and tested circuits are "fleshed out" with component values, and the operation of a wide variety of oscillators is covered. Part One covers Hartley oscillators, and provides useful practical applications as DC-DC converters, metal detection and frequency generators, and variations. An absolutely essential feature on practical analogue electronics, great for hobbyists, not to be missed!
The EPE
Mood PICker is the latest incarnation of our Mood Changer "dream
machine". It's PIC 16F84 based and generates Delta, Theta, Alpha,
and Beta waves in an inductor, and may help stimulate or relax the mind
to help with insomnia and relaxation. The design is budget priced and
easy to build. Compact size will fit under the pillow. Uses two AAA batteries
to provide over 200 hours of operation. PIC source code available from
our FTP site, ready-made PICs also available.
Warning:
not recommended for use by known or possible epileptic sufferers.
Intruder
Deterrent - this self contained gadget turns an ordinary lamp on and
off to give an impression to would-be burglars that the premises are occupied.
Completely self-contained in a "mains adaptor" style enclosure,
this design is simple and safe to build.Also in this issue: Practically Speaking - how to make better connections with sockets and switches; New Technology Update - how new processes are providing improved performance for thick film circuits; Circuit Surgery - our popular "Help Desk" for readers' electronics problems. Net Work - our Internet column, more on Internet hoax viruses.