App note: Bipolar transistors maximum ratings

Deep dive on to the maximum ratings of bipolar transistors presented in this app note from Toshiba. Link here PDF! For transistors, the maximum allowable current, voltage, power dissipation and other parameters are specified as maximum ratings. The absolute maximum ratings are the highest values that must not be exceeded during operation even instantaneously. When […]

USB curve tracer for NPN transistors

Dilshan Jayakody documented his USB port base NPN transistor curve tracer project: Curve tracer is an electronic test instrument to analyze the characteristics of transistors and other discrete semiconductors. In this post we construct USB base curve tracer to analyze properties of NPN transistors. This curve tracer is build around Microchip’s PIC18F4550 MCU and it use […]

Excel-based transistor amplifier calculator

Paulo shared an Excel-based transistor amplifier calculator.  ‘Besides the basic gain and biasing calculations many others implement, this calculator can also estimate noise which is a bit more involved’: ..Because this is a circuit I use frequently, I decided to make an Excel spreadsheet to ease the calculations. The spreadsheet started as a simple resistor […]

Testing the photovoltaic effect with a transistor

When you expose the silicon die of a transistor to a light source a charge is produced. CircuitsDIY opened up a 2n3055 transistor and did some experimenting. With the help of a magnifying glass he was able to built up a charge of 0.65V and produce 42.2mA of current. Most photovoltaic cells are made of […]

The single NPN transistor audio preamp

Hack a Week’s new project this week is a single NPN transistor audio preamp: Here’s a great little project that goes well with the LM386 audio amp. It’s a good first time transistor project because it’s simple and demonstrates the common emitter class A amplifier circuit with only six components in the signal path.