More about phone (291)

1-07-1991 | In many countries, unlike most of the UK, it is still not possible to parallel two or more telephones easily. The circuit described here...

1-03-1991 | It is often socially not acceptable to turn up the volume of your amplifier, receiver or television set. In such cases a pair of headphone...

1-02-1991 | Telephones for use on board aircraft, employing satellite systems around the globe, must be the ultimate in mobile phone use. What was on...

1-10-1990 | The telephone exchange presented here allows up to eight pulse-dialling telephone sets to be connected, and has an option tor connecting c...

1-01-1990 | This automatical telephone answering unit, designed by ELV GmbH, uses a 256-Kbit voice recording circuit to store and replay your spoken m...

1-07-1989 | 054 LOW-NOISE MICROPHONE PREAMPLIFIER The microphone preamplifier described is based on the SSM2015 from Precision Monolithics Inc. (Pmi), w...

1-07-1989 | 058 INFRA-RED MICROPHONE The circuit of this microphone was originally designed to mon- itor a 7-segment display used on the flight deck of...

1-09-1988 | _,eptembe„x MICROPHONE PREAMPLIFIER WITH ACTIVE FILTER by S.G. Dimitriou When a microphone is used a good distance away from an amplifier,...

1-07-1988 | 0 4 WIRELESS HEADPHONES (TRANSMITTER) A circuit for the transmission, with good quality, of the sound output of a TV re- ceiver over a coupl...

1-07-1988 | To arrive at a suitable headphone re- ceiver that meets the requirements of being light, battery-powered, and offer- ing good-quality reprod...