Electric Delay Lines
Electric delay lines are used for shorter delay times (ns to several µs). They consist of a long electric line or are made of discrete inductors and capacitors, which are arranged in a chain. To shorten the total length of the line it can be wound around a metal tube, getting some more capacitance against ground and also more inductance due to the wire windings, which are lying close together.
Other examples are:
- short coaxial or microstrip lines for phase matching in high frequency circuits or antennas
- hollow resonator lines in magnetrons and klystrons as helices in travelling wave tubes to match the velocity of the electrons to the velocity of the electromagnetic waves
- undulators in free electron lasers
Another way to create a delay time is to implement a delay line in an integrated circuit storage device. This can be done digitally or with a discrete analogue method. The analogue one uses bucket-brigade devices or charge coupled devices (CCD), which transport a stored electric charge stepwise from one end to the other. Both digital and analog methods are bandwidth limited at the upper end to the half of the clock frequency, which determines the steps of transportation.
In modern computers operating at gigahertz speeds, millimeter differences in the length of conductors in a parallel data bus can cause data-bit skew, which can lead to data corruption or reduced processing performance. This is remedied by making all conductor paths of similar length, delaying the arrival time for what would otherwise be shorter travel distances by using zig-zagging traces.
Read more about this topic: Delay Line Memory
Famous quotes containing the words electric, delay and/or lines:
“It requires a surgical operation to get a joke well into a Scotch understanding. The only idea of wit, or rather that inferior variety of the electric talent which prevails occasionally in the North, and which, under the name of Wut, is so infinitely distressing to people of good taste, is laughing immoderately at stated intervals.”
—Sydney Smith (17711845)
“Keep on adding, keep on walking, keep on progressing: do not delay on the road, do not go back, do not deviate.”
—St. Augustine (354430)
“Scholars and artists thrown together are often annoyed at the puzzle of where they differ. Both work from knowledge; but I suspect they differ most importantly in the way their knowledge is come by. Scholars get theirs with conscientious thoroughness along projected lines of logic; poets theirs cavalierly and as it happens in and out of books. They stick to nothing deliberately, but let what will stick to them like burrs where they walk in the fields.”
—Robert Frost (18741963)