The commonly available device is the GFCI (Ground Fault Circuit Interrupter) or what is commonly known as the safety switches. In this device when someone gets a shock it automatically switches off the system. After that one has to switch on the safety switch to run the system. Though it prevents any fatal inquiry by cutting off the main line but still it does not prevent the shock. In this case there is no electric shock at all.
It is an electronic system attached to the main electricity board of the house, which covers all electrical lines to shock free power lines. NIF facilitated the testing of his device at IIT Guwahati, which evaluated it and has explained it as below.The working of this device can be explained in three stages 1. At the input stage a Multiphase change over through Automatic switch is built in. This comprises 3 relays and 3 transformers. Purpose of this mechanism is to automatically provide single phase output from 3 phase input when any phase fails or all the phases are active but we need only single phase output as is the case with most of the domestic appliances. Significance of this phase is that input voltage has been reduced to low output voltage so that it will not cause electric shock. 2. Output from stage 1 i.e. Multiphase change over through Automatic switch is fed to second stage called as Double phase/High Voltage vs. Normal Voltage device. In this device 1 relay and 2 transformers are used. Here in case of high voltage due to mixing of 2 or more phases of input supply is taken care of. Also if there is any touch by human being at the final output stages on the live wire, its relay immediately switch the phase to no current stage and prevent electric shock. 3. Output stage uses a specially fabricated transformer with winding for both primary and secondary coils. This transformer steps up the voltage to usable voltage of 220 volts.
Link: Multiphase change over through Automatic switch Easy to use Economic User Friendly
Manufacturing Capacity: b) Design Support, d) Licensing, e) Franchising
Problem Scale: Global