A unijunction transistor is a 3 terminal semiconductor device which is unlike a BJT has only a single pn junction. It is basically designed to be used as a single-stage oscillator circuit for generating pulsed signals suitable for digital-circuit applications. UJT Relaxation Oscillator Circuit The unijunction transistor could be typically wired in the form of […]
Transistor
Calculating Transistor as a Switch
Although transistors (BJTs) are popularly used for making amplifier circuits, these can be also effectively used for switching applications. A transistor switch is a circuit in which the collector of the transistor is switched ON/OFF with relatively larger current in response to a correspondingly switching low current ON/OFF signal at its base emitter. As an […]
Easy Two Transistor Circuit Projects for School Students
A variety of small school projects can be built using just two transistors. This compilation includes a collection of practical and fascinating circuit ideas using just a few number of parts. Any small signal transistor can be used in the proposed two transistor circuit, such as BC547, 2N2222, 2N2907, BC108, BC107, TIP32, TIP31, 188, 8050, […]
Darlington Transistor Calculations
Darlington transistor is a well known and popular connection using a pair of bipolar transistor junction transistor (BJT), designed for operating like an unified “superbeta” transistor. The following diagram shows the details of the connection. Definition A Darlington transistor can be defined as a connection between two BJTs that allows them to form a single […]
How to Troubleshoot Transistor (BJT) Circuits Correctly
Troubleshooting BJT circuits is basically a process of identifying the electrical faults in the network using multimeters across the various nodes in the circuit. BJT troubleshooting techniques is a huge topic and therefore including 100 % solutions and strategies can be perhaps difficult within a single article. Basically, the user should know about a handful […]
Transistor Common Collector
A BJT common collector amplifier is a circuit in which the collector and the base of the BJT share a common input supply, hence the name common collector. In our previous articles we have learned the other two transistor configurations, namely the common-base and the common-emitter. In this article I have explained the third and […]




