Circuits & Schematics Everlight

The exposure tester in this Design Idea measures the on time of a light source, whether an LED, an incandescent lamp, a halogen lamp, or another source. It can be made with an ordinary stopwatch and a few simple components (figures 1 and 2). An ...

Junction field-effect transistors (JFETs) usually require some reverse bias voltage to be applied to a gate terminal. In HF and UHF applications, this bias is often provided using the voltage across the source resistor R S (Figure 1). Figure 1. ...

EDN IR (infrared)-proximity sensors can sense the presence of an object, its distance from a reference, or both. Applications include speed detection, sensing of the hand in automatic faucets, automatic counting or detection of objects on conveyer ...