Donald Schelle

Solid-state-lighting applications are quickly moving into the mainstream. Although they are more efficient, the LEDs that produce the low-cost light often require a complicated driver circuit. Testing the driver circuit using LEDs, although easy, yields only typical results...

Mechanical push-pushbutton switches (also known as alternate-action or push-on/push-off switches) can be bulky and expensive. As an alternative, an electronic version uses a cheaper, NO (normally open), momentary-on switch (Figure 1). Figure...

A USB port offers a handy source of 5 V power for auxiliary devices. A USB port not only supplies power to a microcontroller and other essential circuitry, but also provides enough extra current head room to charge a small battery or supercapacitor energy-storage...