Teledeltos
Teledeltos paper is an electrically
Teledeltos paper has several uses within engineering that are far removed from its original use in spark printers. Many of these use the paper to model the distribution of electric potential and other scalar fields.
Use
Teledeltos provides a sheet of uniform
The resistivity of Teledeltos is around 6 kilohms / square.[2][i] This is low enough that it may be used with safe low voltages, yet high enough that the currents remain low, avoiding problems with contact resistance.
Connections are made to the paper by applying areas of silver-loaded
A sheet that is large in comparison to the experimental area is usually sufficient for modeling an infinite field.[3]
Modelling fields by analogy
Although the modelling of electric fields is itself directly useful in some fields such as
Before the use of Teledeltos, a similar technique had been used for modelling gas flows, where a shallow tray of
One of the most important applications is for thermal modelling. Voltage is the analog of temperature and current flow that of
As heatsinks are commonly manufactured from
This thermal modelling technique is useful in many branches of mechanical engineering such as heatsink or radiator design and die casting.[7]
The development of
Sensors
Teledeltos can also be used to make sensors, either directly as an embedded resistive element or indirectly, as part of their design process.
Resistive sensors
A piece of Teledeltos with conductive electrodes at each end makes a simple resistor. Its resistance is slightly sensitive to applied mechanical strain by bending or compression, but the paper substrate is not robust enough to make a reliable sensor for long-term use.
A more common resistive sensor is in the form of a
A similar linear sensor uses two strips of Teledeltos, placed face to face. Pressure on the back of one (finger pressure is enough) presses the two conductive faces together to form a lower resistance contact. This may be used in similar potentiometric fashion to the conductive probe, but without requiring the special probe. This may be used as a classroom demonstration for another electronic musical instrument, with a
Capacitive sensors
Although Teledeltos is not used to manufacture capacitive sensors, its field modelling abilities also allow it to be used to determine the capacitance of arbitrarily shaped electrodes during sensor design.[2]
See also
- Finite element analysis
- Hydraulic analogy
- Space cloth
Notes
- ^ Note that the resistivity units for a two-dimensional sheet are ohms / square (), not the ohm metre(Ω⋅m)s that would be used for the resistivity of a bulk resistor.
References
- ^ Grosvenor Hotchkiss, Electrosensitive Recording Paper for Facsimile Telegraph Apparatus and Graphic Chart Instruments, Western Union Technical Review, Vol. 3, No, 1 (January 1949); page 6.
- ^ ISBN 078035351X.
- ^ a b c "Field Plotting Using Teledeltos Paper" (PDF). Department of Electronic Engineering and Applied Physics, Aston University. Archived from the original (PDF) on 2004-07-18.
- ^ a b Bob Pease (30 May 1994). "What's All This Teledeltos Stuff, Anyway?".
- ISBN 1-85310-285-7.
- ^ Chamberlin, R.H. (1963–1964). "The Napier Deltic Diesel Engine in Main-line Locomotives". Proc. Inst. Mech. Eng. 178 (3): 66.
- ^ John L., Jorstad (September 2006). "Aluminum Future Technology in Die Casting" (PDF). Die Casting Engineering: 19. Archived (PDF) from the original on 2011-06-14.