[Eric Wasatonic] had a box of SWB2433 transistors that he had very little information about. In order to discover their properties, he fired up his curve tracer to compare these transistors with more ...

A previous Design Idea describes a circuit that uses an astable multivibrator to drive an LED (Reference 1). The circuit in Figure 1 uses a simpler alternative approach. The circuit uses a 2N3904 NPN ...

Frank Hertel’s project: three individually dimmable LED lights. (Frank is the master of recycling; the wooden mounting pedestals are the panels from a decommissioned ATI console!) Thanks for your ...

The circuit has been constructed to provide an in-circuit system that will test the integrity of electronic components such as Silicon Controlled Rectifiers, diodes, and PNP or NPN transistors. 4093 – ...

With cycling safety in mind, I bought a pair of low power red LED things that replace the bungs in the end of drop handlebars. They are a neat way to get a bit of extra visibility – and to give a ...

Fig 1. This voltage regulator circuit (a) uses green LEDs as both the stabilization elements and as the voltage indicators at the front-panel switch (b). Fig 2. The addition of resistor R4 to the ...