E-Throttle

Insulation Resistance All know that the resistance of a pure insulation is infinity. But to no extend we can make a pure insulation. So we have a small leakage current to flow through insulation depending upon the voltage applied. Thus as the result we get a resistance value in the range of Mega Ohms(MΩ) or Giga Ohms(GΩ).   Here the applied voltage is DC. We have separate kit for injecting the DC voltage. Usually that equipment is known as megger. The two windings are connected as in the diagram above and Megger is used to measure the insulation resistance. It applies a high voltage normally 500V or 1kV for time period of minimum 30 seconds to One minute and the respective resistance are noted down. Usually for a new transformer, result value will be in Giga Ohms(GΩ). During the ageing, deposition of dust, moisture and other unwanted particles can cause the megger value to reduce. So to gain the resistance back to normal, the dust deposited should be removed, moisture shoul...

  Lightning.....! the wicked thing in our power system.                     For us it creates only damages. So is important to protect the crores worth devices which support the generation, transmission and distribution of power. Starting from the generating stations, all the power cables are connected to a device which is called surge diverter or lightning arrester. In transmission towers we draw a separate line for earth at the top of the tower. By that line we create a zero potential at the top of tower. Thus protecting transmission lines from lightning surges. Electrical surge produces a large transient over voltage in the electrical network and system. The shape of the transient over voltage has a steeply rising front with slowly decaying tail. There are two types of surges one comes externally from atmosphere such as atmospheric lightning. Second type is originated from electrical system itself, such as swi...

Are you excited about Electricity ? You may have to know much about the enormous behavior of  current. No, it wont bite you unless you are not cared about it.      Here we bring some safety and protection aspects in electrical power handling. As we know the current is the flow of charges, which exists if and only if  there is potential difference and a closed loop(otherwise ideally we could say infinite resistance in the path, resulting in zero current).    When we are focusing on our safety its better to consider the after effects as there is a potential and closed path, when we make some contacts.It's all that matters is the threat of electrical shock . It depends on the power level of the source, that it could circulate a certain amount of charge per second through your body. The different current levels and effects are as follows  1mA - some threshold of sensation 10mA - effect may vary from Mild sensation to painful shock ...