Poncet Platform

A Poncet platform or Poncet - mount is a type of equatorial platform.

Function

It is named after its inventor. This type of telescope mount makes it a Dobsonian telescope to get a smooth tracking, as well as with reflectors or refractors which have a motor-driven GoTo mount, or another tracking system. The telescope thus follows the movement of the starry sky, without having to run the Dobson typical " Nachschubsen ". This gives room for longer observation times and also allows astrophotography on Dobsonian telescope, which is virtually impossible without equatorial platform because of Dobson was designed for purely visual observation.

Backgrounds and use

Invented in 1970 by Adrien Poncet. Described in 1977 in the January issue of "Sky and Telescope " and illustrated. Often a simple plywood construction designed with a strong ground, carrying the weight of a Dobson including substructure. The Poncet platform can be realized without complicated and expensive special tools, with DIY knowledge and a normal household workshop, as well as some materials which are available in any hardware store. There platforms were built in all sizes, from huge platforms that carry complete small observatories, to miniature formats. The angle of the circular cutout on the bottom edge of the upper plate is derived from the longitude, and makes it possible to shoot the entire superstructure in an imaginary extended axis of the Pole Star. Should the platform be used in an observatory which is located at 50 ° north latitude, the angle must be adjusted accordingly. One can therefore use only a function of location the platform. If you were to build a platform that is used directly over the equator, one would theoretically only one board screw it on a roll or barrel, it then the Dobson telescope mounted, and a längenregulierbare support strut mount. However, since few people live on the equator, a circle cut-out must be used (upper panel), which slides on rollers or bearings ( lower panel ).

The platform allows an adequate tracking even at higher magnifications and astrophotography. The Nachführdauer is usually limited to about 1 h, similar to a " barndoor tracker ", after which I reset the platform, then you must realign the Dobson, before you continue " spechteln " can. Another version of equatorial platform is the " Gee- platform " as well as the platform of Georges D' Automne.