A hole needs to be digged at the lowest place in the celler that have water incomming problems. The hole is about 0.5 x 0.5 x 0.5 meter, at the bottom a large water pump is mounted. Then the different water levels was measured, so we know how to make the sensors.
Read more original [...]
The circuit will limit the current through the supply wires to 5.5A for about 1.5sec. After that time the relay will close and the current flow won’t be restricted anymore. This is a very interesting circuit if you have a large toroid with big electrolytic caps connected to the power supply, since these will act [...]
It is well know that pests like rats, mice etc are repelled by ultrasonic frequency in the range of 30 kHz to 50 kHz. Human beings can’t hear these high-frequency sounds. Unfortunately, all pests do not react at the same ultrasonic frequency. While some pests get repelled at 35 kHz, some others get repelled at [...]
Best View 800x600 pixel
Email : 
Copyright 2008 www.elecfree.com/electronic/
Genwi
Entries (RSS)
