ok, I know its been a while. These days, I am rather busy elsewhere so get little time to work on electronics or radio, and so the blog updates come less frequently. Some recent family issues also have given me even less time.
But, theres nothing like an upcoming astronomical event to drive the completion of a project! Last night I spent a couple of hours meteor and satellite spotting with my eldest lad. With the Perseids meteor shower due to peak this weekend, I pushed myself to finally complete the Dew Heater.
Very little needed to be done, just the connections for the temperature sensor and building a power cable. Plus testing, and finally completing the housing.
The power cable is a DC jack to crocodile clip lead, to allow the controller to be used with my many standard 7Ah SLABs. The temperature probe, which will be secured to the camera lens by the heater strap, required some cross-over wiring to connect it to the phono cable tail I already had (salvaged) in its parasitic power mode - taking it from a 3-wire to a 2-wire device.
Testing using body heat and freezer spray showed the sensors to be working correctly, and the heater controls firing as expected.
The next test will be the big one - how well it actually handles its job of keeping the camera lens demisted in the early hours of tomorrow morning! With the controller dealing with the lens and ambient temperatures, and the dewpoint, and the camera running continuous 15sec f1.8 18mm ISO 1600 exposures, all I can hope for is clear skies!
