In this article we talk about a few simple yet accurate transistor tester circuits which can used to identify whether a transistor is good or bad. Note: Please test *only* BJTs and MOSFETs (enhancement or depletion) with these circuits. Simple Good/Bad Transistor Checker using a Single LED Do you have a lot of strange old transistors […]
Circuits
5 Simple Power Bank Circuits for Mobile Phones
In this article I have explained a 5 assorted power bank circuits using 1.5V cell and 3.7V Li-ion cell which can be built by any individual for their personal emergency cellphone charging functionality. The idea was requested by Mr. Irfan What is a Power Bank Power bank is a battery pack which is used to […]
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 […]
How to Design MOSFET Power Amplifier Circuits – Parameters Explained
In this post I have explained various parameters that must be considered while designing a MOSFET power amplifier circuit. We also analyze the difference between bipolar junction transistors (BJT) and MOSFET characteristics and understand why MOSFETS are more suitable and efficient for power amplifier applications. Contributed by Daniel Schultz Overview When designing a power amplifier […]
How to Make Pierce Oscillator, Hartley Oscillator Circuits
In this post I have explained how to build simple oscillator circuits like the pierce oscillator and hartley oscillator using a single CMOS gate. Both the oscillators are types of oscillators that utilize minimum number of components yet are able to generate very stable and reliable frequency outputs. You might also want to learn How […]
3 Tested 220V High and Low Voltage Cut OFF Circuits Using IC LM324 and Transistors
An AC mains high/low cut-off device will cut off or disconnect the mains supply from home electrical whenever a high voltage or low voltage situation is detected. In this way it ensures total safety to the home wiring and appliances from fire hazards, due to abnormal over voltages, brown outs or low voltages. In this […]





