This controller regulates the power of up to 4 dew heaters with RCA connectors. Each of the two dials controls 2 dew heaters. The power is off when the knob is to the left and the heating power increases by turning the knob clockwise. The two top connectors are controlled by the left knob and the two bottom connectors by the right knob. The controller needs 12V input voltage via a cigarette lighter plug. Power can be supplied by a power tank, sealed lead-acid battery or a suitable power-supply unit. The maximum input current is 10A (normally this power need is not necessary) so a 17Ah power tank or an equivalent battery is sufficient to last at least a whole night. Telescopes and camera lenses are made up of metal so they cool down fairly quickly outdoors. When air humidity reaches the dew point, moisture will condensate on optical tubes, lenses and mirrors resulting in a quick end to observations or photography. With open optical tubes, like Newtonian telescopes, dew does not only form at the outside of the tube but also on the primary and secondary mirror. Heating sleeves and heating elements increase the temperature close to the optics, thus reduce the risk of dew formation, but it can also increase tube turbulence due to unnecessary thermal output. Adjusting the thermal output by a controller is very important to minimise the turbulence caused by the heat. With this controller you can keep the temperature in the tube or around the optics only a few degrees above the air temperature, achieving dew protection and minimising tube turbulence. Another advantage of the temperature controller is the low energy consumption. With this controller you can use all common heating sleeves for secondary mirrors, primary mirrors, dew shields and dew bands with RCA connectors. Specifications Output 4 RCA connectors - controlled by 2 control dials Maximum current 10 Amp Power supply 12V DC (cigarette lighter)
