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Often, in addition to the continuous rating, separate SOA curves are also plotted for short duration pulse conditions (1 ms pulse, 10 ms pulse, etc.). The safe operating area curve is a graphical representation of the power handling capability of the device under various conditions.
Switchgear [5] includes the power switching components, e.g., the main disconnecting device, and breakers protecting the supply conductors and the branch circuits in the machine. Controlgear [ 6 ] includes all of the control system components downstream of the switchgear, out to the final point of control, but not including the machine actuators.
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.
One style of current limiting circuit is shown in the image. The schematic represents a simple protection mechanism used in regulated DC supplies and class-AB power amplifiers. Q1 is the pass or output transistor. R sens is the load current sensing device. Q2 is the protection transistor which turns on as soon as the voltage across R sens ...
Snapback is a mechanism in a bipolar transistor in which avalanche breakdown or impact ionization provides a sufficient base current to turn on the transistor. It is used intentionally in the design of certain ESD protection devices integrated onto semiconductor chips.
Reference voltage vs free-air temperature at test conditions. Design-center (middle plot) and worst-case deviation of ±2% (upper and lower plots) [12] The nominal reference voltage, V REF =2.495 V, stated in a datasheet, is tested in zener mode at an ambient temperature of +25 °C (77 °F), and I CA =10 mA. [13]
To test the lack of latch-up, the prototype 1200 V IGBTs were directly connected without any loads across a 600 V constant-voltage source and were switched on for 25 microseconds. The entire 600 V was dropped across the device, and a large short-circuit current flowed. The devices successfully withstood this severe condition.
Conditional short-circuit current is the value of the alternating current component of a prospective current, which a switch without integral short-circuit protection, but protected by a suitable short circuit protective device (SCPD) in series, can withstand for the operating time of the current under specified test conditions.