Posted: Thu Dec 14, 2006 10:52 am
Rich 1 is right. The DewBuster controller is very useful for the following:On the contrary, the controller may be essential. Most of us are using up to a 7AH battery only but these dew heaters are meant to be used with bigger batteries. Their current drain at default may be so high as to deplete your battery (which may be powering your scope also) before the night is over.
In addition, the heat is meant to be able to keep the scope warm in very cold weather, hence it may be too hot for warmer temp in this region...
1. It allows you to neatly link up to 8 dew heaters to one battery thru the controller. You need this many links for dew heater straps to corrector plate, eyepiece, finder objective, finder eyepiece, telrad etc.
2. More importantly, it also has a ambient temperature sensor link to the controller that allows you to set/vary the heat output to achieve, say, 4 deg C above the ambient temperature. The controller will automatically increase or decrease the heat accordingly as the night temperature varies thru the night. This effectively keeps dew away the whole night and you conserve your battery life so that you just need a battery which is smaller & lighter.
3. It has a built-in safety device and warning light to reduce and cutoff the battery once the voltage drops to 10 volts, otherwise the lead-acid battery may be damaged.