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Old 20-02-2014, 12:43 PM
PeterHA (Peter)
Murphy's Friend

PeterHA is offline
 
Join Date: Jun 2013
Location: Glen Waverley, Melbourne
Posts: 133
DIY dew controller and Telrad fix

All,
Following ideas others have published in the past, here my cheap dew controller and Telrad fix.
Aim was to have only one cable from battery pack to mount and only one from mount to telescope.

I have build a small dew controller using a $4 LED dimmer from eBay (only PCB) a small box (8x5cm), it has two outputs for heaters (up total 48W) and one input for 12V and allows an 12V output for the Nexus on the mount, so only one cable from Battery for all equipment.
A LED ramps in brightness with heater output, the heater circuit has a fuse.
The thing will attach per velcro on top of my Nexus WiFi which sits on the mount.


Also a Telrad mod with permanently build in heater (2 resistors total of 2W), a connection for a second heater and a connector to the controller. This will allow me to connect a scope heater strap with a short cable to the front Telrad connector and the cable from the second connector to the controller is the only cable between scope and controller on the mount.

Start of my prep for the dewy weather.
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