Recently, Dortronics received a request to design and manufacture an indicator that could be mounted near card readers to clearly indicate when individual doors were open or locked. The problem arose ...

Designed for front-panel mounting in 12- and 16-mm holes with panel thicknesses of up to 6.3 mm, a family of LED indicators are available in versions providing up to 60 mcd in red, 110 mcd in green, ...

Using a few diodes and a LED, you can make a nice indicator as shown in associated schematic diagram that can be used for a lot of applications (with a bit of luck). It’s quite suitable for use in ...