How is a transistor used in a solid state switch?
Solid state switches are one of the main applications for the use of transistor to switch a DC output “ON” or “OFF”. Some output devices, such as LED’s only require a few milliamps at logic level DC voltages and can therefore be driven directly by the output of a logic gate.
What is the current state of the Cisco switch stack?
Table 1 Current State Output and Descriptions Current State Description Ready The switch is fully operational. Progressing The stack master is communicating with t Provisioned Ports are assigned in the stack
How does a Darlington transistor work as a switch?
Darlington Transistors simply contain two individual bipolar NPN or PNP type transistors connected together so that the current gain of the first transistor is multiplied with that of the current gain of the second transistor to produce a device which acts like a single transistor with a very high current gain for a much smaller Base current.
What happens when you disconnect a switch from a stack?
An active switch connected to a fully operational stack becomes a stack member. It receives the running configuration from the stack master. When you disconnect a stack member, the switch numbers and port numbers of the remaining stack members do not change, and the switches do not reload.
What’s the maximum current a transistor can draw?
According to the datasheet for this motor, at 12VDC with no load it only draws 76 mA, but if you stall the motor it shoots up to 1250 mA, or 1.25 Amps. A motor always consumes the maximum current when stalled.
Can a PNP transistor be used as a switch?
A motor always consumes the maximum current when stalled. Thus the load voltage is 12VDC and the maximum load current is 1.25 A Vload = 12V Iload (max) = 1.25A In general, we can use both PNP or NPN transistors as switches. However, PNP transistors can only control the same voltage as is supplied to the Arduino chip.
What’s the difference between a transistor and a NPN switch?
The equations for calculating the Base resistance, Collector current and voltages are exactly the same as for the previous NPN transistor switch. The difference this time is that we are switching power with a PNP transistor (sourcing current) instead of switching ground with an NPN transistor (sinking current).
What are the operating conditions of a transistor?
Here the operating conditions of the transistor are zero input base current ( IB ), zero output collector current ( IC ) and maximum collector voltage ( VCE ) which results in a large depletion layer and no current flowing through the device. Therefore the transistor is switched “Fully-OFF”.