My rig is now almost complete as in the pic. The final piece will be the dew control. The ASIAIR Pro has 4 2.1mm round pin power ports although I think few straps are all RCA connectors.
I believe you can get adapters indeed ASI make a splitter with a round pin on one end and two RCA connectors on the other. I don’t know if anyone makes dew straps that already have a 2.1mm connector?
Anyway, the main point is, whilst I presume the ASIAIR can power them it is a simple on/off. Does anyone use this mechanism or do you need/use and separate controller and if so, which one?
You should really use some form of a controller so you don't cook your OTA and draw too much power from your battery (or power supply)
The simplest controller works basically like a light dimmer on your home. Turn a dial to modify the average current to the heat strip. (variable length of pulses to the strip depending on dial position)
This method is a bit hit and miss as you may or may not dial the right value to keep the dew off the mirror or lens.
Dew will form on the surface when the surface gets below the dew point. So a controller that monitors both temperature and humidity, calculates the dew point and keeps the surface above the dew point is the best. This will save unnecessarily heating the surface creating unnecessary hot air turbulence and also reduce battery drain.
A compromise controller is one that measures the ambient air temperature as well as the temperature of the surface and strives to keep the surface say 3 degrees above ambient. The Kendrick Digifire FX Pro is an example of this type of controller. (and the long-promised Kendrick Premier Controller due promised now for mid-2021 is an example of a dew point controller)
Some telescope controllers/power systems, also have built-in dew controllers of varying capabilities. You can usually pick the type by the controls and sensors. If they have a dial, odds are it's a simple controller. If just a temperature sensor near the band and an air temp sensor, I'd guess an ambient temp control. If they also have a humidity sensor, then probably a dew point controller.
I have the ASIAIR Pro
You can configure the dc output for dew control & then it reverts to a percentage Power output
You then use slider to adjust output to dew heaters