delay line
delay line An electronic device that produces a finite accurate time delay between a signal imposed on its input and the appearance of the same signal at its output. These devices may be used as short-term signal stores or to provide accurate delays in signal-processing circuits. In an acoustic delay line electrical signals are converted into a pattern of acoustic (sound) waves that travel through a medium between a transmitter and receiver.
Delay lines were the most common storage devices in first-generation computers: this acoustic memory was used, for example, in EDSAC, EDVAC, pilot ACE and ACE, UNIVAC 1, and LEO 1. In EDSAC (1949), quartz crystals were used as transducers and the ultrasonic pulses were passed along a tube of mercury about 5 feet (1.5 meters) in length. The delay was approximately 1 millisecond but it enabled nearly 1000 pulses to be stored. Later acoustic memory used magnetostrictive transducers and nickel-iron wire, with the electrical signals converted into stress waves.
Although delay lines as storage devices have been superseded by more cost-effective components they are still to be found in almost all computer motherboards, where they are used to equalize the delay between signals in parallel busses, as found with most microprocessors operating at 100 MHz or more. RCB tracks are used to present equal path lengths for each signal, enabling fast clocking to be used.
Delay lines were the most common storage devices in first-generation computers: this acoustic memory was used, for example, in EDSAC, EDVAC, pilot ACE and ACE, UNIVAC 1, and LEO 1. In EDSAC (1949), quartz crystals were used as transducers and the ultrasonic pulses were passed along a tube of mercury about 5 feet (1.5 meters) in length. The delay was approximately 1 millisecond but it enabled nearly 1000 pulses to be stored. Later acoustic memory used magnetostrictive transducers and nickel-iron wire, with the electrical signals converted into stress waves.
Although delay lines as storage devices have been superseded by more cost-effective components they are still to be found in almost all computer motherboards, where they are used to equalize the delay between signals in parallel busses, as found with most microprocessors operating at 100 MHz or more. RCB tracks are used to present equal path lengths for each signal, enabling fast clocking to be used.
More From encyclopedia.com
Bugs (microphones) And Bug Detectors , Bugs (Microphones) and Bug Detectors
█ BRIAN HOYLE
A key part of intelligence gathering and surveillance is the installation of listening devices. Th… Transducer , A transducer is an electronic device that converts one form of energy to another energy form for such purposes as measurements and information transf… device , de·vice / diˈvīs/ • n. 1. a thing made or adapted for a particular purpose, esp. a mechanical or electronic contrivance: a measuring device. ∎ an exp… Analog-to-digital Conversion , In the field of computing, information can be conveyed in digital or analog formats. Continuity is the differentiating factor between the two. For ex… Analog Computer , Computer, Analog
A digital computer performs calculations based solely upon numbers or symbols. An analog computer, on the other hand, translates con… Usb , USB Abbrev. for universal serial bus. An external peripheral interface standard for communication between a computer and external peripherals over lo…
You Might Also Like
NEARBY TERMS
delay line