Elements

A ZeroDew system consists of a digital controller and one or more heating bands. The controller can be directly connected to batteries or to a power source of the car lighter type (depending on the version). The bands must be connected exclusively to the controller by means of the 4 outlets provided for such purpose.

Use

  1. Place the band or bands on the telescope (or finder, ocular…) in such a way that the rugged part of the band remains towards the outside and the cable in the direction where the controller is to be installed. Try to place the band as close as possible to the element that is intended to be protected from the humidity (correcting sheet, objective of the refractor…). See photo below. Heater band fitted around the front of a telescope tube, secured with Velcro
  2. Firmly fix it with the Velcro.
  3. Connect the band or bands to the controller.
  4. At last, connect the controller to the power source.
  5. The outlet is adjusted by means of the potentiometer; it is convenient to reach the lower position where the humidity is avoided, in order to minimise battery consumption and to avoid excessive heating.

The controller has a system of protection against the discharge of the batteries; in the case when the outlet voltage of the battery reaches a minimum value, a red indicator shall light and outlet power shall cease to be supplied. That shall avoid the battery suffering irreparable damage.

Failures and repairs

If, for any reason, the ZeroDew controller ceases to work, first of all check the connections and the charge of the batteries, and also check if any fuse is blown (there is one of 10A within the controller, and in the version for the car lighter there is another one within the adapter—it is only necessary to unscrew the "nose" of the adapter to access it, no tools required—this last one is of 3A).

Safety warnings

  • The system must be exclusively connected to power sources or batteries of 12V.
  • The bands must be placed on the telescope, ocular, etc. before supplying power. Particularly, the resistors must never be heated while being wrapped on themselves.
  • The fuses must be replaced by equal ones.