Projects in the September 2001 issue of EPE Magazine
LED Flashlights - Two dazzling designs for LED torches, featuring a simpler hi-bri red LED version suitable for reading by, and a more sophisticated switched-mode circuit for an ultra-bright white LED version. Battery operated, efficient portable designs sure to impress your friends.
Perpetual Projects Continuing with our mini circuits which use a modest solar panel to charge a "Gold Cap" capacitor during the day, which in turn powers a mini circuit "for ever"! This month a Loop Burglar Alarm, Touch Door Light (illuminates e.g. a keyhole at night for a short duration) and Perpetual Rain Alarm are described, based on the solar-power supply of the July issue.
Water Monitor - How much does it cost to keep your garden watered? To find out, build our Water Monitor, a PIC-controlled water flow measurement and auto shut-off device. You can also program in the cost of water per cubic metre and the Water Monitor will display the cumulative water consumption and cost on its LCD display. Requires PIC16F84 (source code available free from EPE's FTP site), plus an RS WaterFlow Sensor/ Solenoid Valve. 12V d.c. operated.
50 or 60 Hz Synchronous Clock Driver - due to popular demand, we present a dual frequency mains circuit which converts 230V a.c. 50 Hz British mains supply to a 115V a.c. 60Hz one suitable for powering imported synchronous clocks. Can also be modified for use overseas, to operate British 230V 50Hz equipment on a 115V 60Hz supply.

Also in this issue, Ingenuity Unlimited (readers' own circuit ideas), New Technology Update trends in component package sizes. Circuit Surgery describes the use of decoupling capacitors in parallel. Net Work — The Internet Page — looks forward to satellite internet connections.Special feature — Controlling Flight — an insight into how electronics helps maintain air safety.