Xerography (electrophotography)

Xerography is a dry photocopying technique that was invented by Chester Carlson in 1938. It uses an electrically charged photoconductive surface to attract and transfer toner particles onto paper. The first commercial xerographic copier was the Xerox 914, which was introduced in 1959. Since then, xerography has become the dominant photocopying technology. Is xerography still … Read more


Troubleshooting is the process of identifying and resolving problems with computer hardware or software. Troubleshooting often involves trial and error, as well as a systematic approach to solving problems. When troubleshooting hardware, technicians may use a process of elimination to identify the faulty component. This involves removing, testing, and then re-installing components until the problem … Read more

Mantrap (interlocking door controller)

A mantrap is an interlocking door controller which is used to control access to a secured area. It typically consists of two doors which are connected by an electronic lock. The first door is usually an outer door which is unlocked and allows entry into the mantrap. The second door is usually an inner door … Read more