Electronic Projects in the Workshop

The purpose of this book is to provide a number of useful and interesting electronic constructional projects for use in and around the workshop. The projects will have considerable appeal to the home handyman and will find use in the average «Do It Yourself» workshop. Many of the circuits are very versatile, and could easily be adapted to perform different functions. All the projects are reasonably simple and have been designed so that they are not beyond the constructional capabilities of anyone who is reasonably practical, and many are suitable for beginners at electronics construction. Contents 1. Rain/water level alarm 1 2. Flat battery warning light 6 3. Thermometer 11 4. Auto turn on/off switch 17 5. Timer unit with audio alarm 22 6. Ultrasonic transmitter 28 7. Ultrasonic receiver 33 8. Telephone repeater 38 9. Telephone amplifier 43 10. NiCad battery charger 49 11. Mains/9 volt adapter 54 12. Lamp dimmer 59 13. Multimeter sensitivity booster 65 14. Capacitance bridge 71 15. Bench power supply 76