Search results
Results From The WOW.Com Content Network
A short circuit fault current can, within milliseconds, be thousands of times larger than the normal operating current of the system. [2] Damage from short circuits can be reduced or prevented by employing fuses , circuit breakers , or other overload protection , which disconnect the power in reaction to excessive current.
Secondary breakdown is a failure mode in bipolar power transistors. In a power transistor with a large junction area, under certain conditions of current and voltage, the current concentrates in a small spot of the base-emitter junction. This causes local heating, progressing into a short between collector and emitter.
The entire 600 V was dropped across the device, and a large short-circuit current flowed. The devices successfully withstood this severe condition. This was the first demonstration of so-called "short-circuit-withstanding-capability" in IGBTs. Non-latch-up IGBT operation was ensured, for the first time, for the entire device operation range. [22]
Current limiting is the practice of imposing a limit on the current that may be delivered to a load to protect the circuit generating or transmitting the current from harmful effects due to a short-circuit or overload. The term "current limiting" is also used to define a type of overcurrent protective device.
Bipolar disorder can also involve depressive episodes, which have the same symptoms that people with major depressive disorder experience. Symptoms of a depressive episode can include:
Bipolar disorder is among the top 20 causes of disability worldwide and leads to substantial costs for society. [26] Due to lifestyle choices and the side effects of medications, the risk of death from natural causes such as coronary heart disease in people with bipolar disorder is twice that of the general population. [4]
In an electric power system, a fault or fault current is any abnormal electric current. For example, a short circuit is a fault in which a live wire touches a neutral or ground wire. An open-circuit fault occurs if a circuit is interrupted by a failure of a current-carrying wire (phase or neutral) or a blown fuse or circuit breaker.
A resistor removed from a high voltage tube circuit shows damage from voltaic arcing on the resistive metal oxide layer. Resistors can fail open or short, alongside their value changing under environmental conditions and outside performance limits. Examples of resistor failures include: Manufacturing defects causing intermittent problems.