More about phone (291)

1-09-1995 | On much audio equipment, the headphone output is simply derived from the loudspeaker output via a series resistor: not a very elegant desi...

1-07-1995 | Although most modern telephones, in particular, those with a number memory, already have a flash key, there are many excellent sets aroun...

1-03-1995 | A switch, based on a PIC(1) RISC(2) processor, is described that enables mains-operated equipment, such as a computer, a coffee maker, or...

1-12-1994 | The push-pull driver transistors in output amplifiers must be as closely complementary as possible. The selector matches pairs of comple...

1-12-1994 | Although many older telephone sets are electrically and mechanically perfectly sound units, their speech quality is poor compared with t...

1-06-1994 | In the UKs Iiberalised telecommunications environment, opportunities exist for those able to provide innovative services costeffectively,...

1-04-1994 | Music should be heard and enjoyed as if the orchestra were right in front of you. Unfortunately, neighbours, children and other members of...

1-01-1994 | The switching unit described here is capable of controlling up to seven mains-powered loads with the aid of commands received via telephon...

1-12-1993 | Undesired listening-in to telephone conversations may be prevented by the present circuit, which requires only two components to protect...

1-12-1993 | The delay circuit ensures that a car's intertor light remains on for about five seconds after all the doors have been closed. This enable...