Darlington Transistor

 

The Darlington Transistor configuration of two bipolar transistors offer increased current switching for a given base current. The Darlington Transistor named after its inventor, Sidney Darlington is a special arrangement of two standard NPN or PNP bipolar junction transistors (BJT) connected together. The Emitter of one transistor is connected to the base of the other to produce a more sensitive transistor with a much larger current gain being useful in applications where current amplification or switching is required.


Darlington Transistor pairs can be made from two individually connected bipolar transistors or one single device commercially made in a single package with the standard: Base, Emitter and Collector connecting leads and are available in a wide variety of case styles and voltage (and current) ratings in both NPN and PNP versions.

As we saw in our Transistor as a Switch tutorial, as well as being used as an amplifier, the bipolar junction transistor, (BJT) can be made to operate as an ON-OFF switch as shown.

Comments

Post a Comment

Popular posts from this blog

wide area network

Image
  A wide area network (also known as WAN), is a large network of information that is not tied to a single location. WANs can facilitate communication, the sharing of information, and much more between devices from around the world through a WAN provider. WANs can be vital for international businesses, but they are also essential for everyday use, as the internet is considered the largest WAN in the world. Keep reading for more information on WANs, their use, how they differ from other networks and their overall purpose for businesses and people, alike. As described above, wide area networks are a form of telecommunication networks that can connect devices from multiple locations and across the globe. WANs are the largest and most expansive forms of computer networks available to date. These networks are often established by service providers that then lease their WAN to businesses, schools, governments, or the public. These customers can use the network to relay and store data or
Read more

Virtual Local Area Network

Image
  Virtual Local Area Network or Virtual LANs (VLANs) are a logical group of computers that appear to be on the same LAN irrespective of the configuration of the underlying physical network. Network administrators partition the networks to match the functional requirements of the VLANs so that each VLAN comprises a subset of ports on a single or multiple switches or bridges. This allows computers and devices in a VLAN to communicate in the simulated environment as if it is a separate LAN. VLAN  is a custom network that is created from one or more local area networks. It enables a group of devices available in multiple networks to be combined into one logical network. The result becomes a virtual LAN is administered like a physical LAN. The full form of VLAN is defined as Virtual Local Area Network. The below topology depicts a network having all hosts inside the same virtual LAN. Without VLANs, a broadcast sent from a host can easily reach all network devices. Each and every device
Read more

Junction Field Effect Transistor

Image
The Junction Field Effect Transistor , or JFET is a voltage controlled three-terminal unipolar semiconductor device available in N-channel and P-channel configurations In the  Bipolar Junction Transistor   tutorials, we saw that the output Collector the current of the transistor is proportional to input current flowing into The base terminal of the device, thereby making the bipolar transistor a “CURRENT” operated device (Beta model) as a smaller current can be used to switch a larger load current. The  Field Effect Transistor , or simply  FET   however, uses the voltage that is applied to their input terminal, called the  Gate  to control the current flowing through them resulting in the output current being proportional to the input voltage. As their operation relies on an electric field (hence the name field effect) generated by the input  Gate  voltage, this then makes the  Field Effect Transistor  a “VOLTAGE” operated device. The  Field Effect Transistor   is a three-termin
Read more