EAGLE allows you to distribute power to many devices used in telescopes and astrophotography (such as computerised mount, cooled camera, electronic focuser, dew heaters, etc.), thus eliminating the need for many different power supplies. Since the EAGLE allows you to have a unique power source (battery or AC adapter), it’s important to select the correct power source to properly power all the devices you want to use. CAUTION: EAGLE must be powered with 12V regulated voltage. You can use a power supply with 12V output voltage or a field battery. If you use a battery, this MUST be provided with a proper voltage stabilization. In case of any malfunction, immediately unplug the power supply.
Which power source have I to use for my equipment?
The power supply or battery you need to use to power the EAGLE and all peripherals connected to it depend on the electric current needed to power all the instruments and the EAGLE. Let’s make an example by considering the EAGLE basic model:
– Computerised mount: 4A maximum consumption
– EAGLE: 1A maximum consumption
– Cooled camera: 4A maximum consumption
– Dew heaters: 1A maximum consumption
In most instances, devices like your filter wheel, focuser and guide camera won’t require separate 12V power since they get their power through the USB ports of the EAGLE.
Total maximum power consumption: 10A.
So, for this setup, you should use the 12.8V 14A AC adapter. If you want to use a battery (WARNING: The battery must have a 12V voltage regulator with protection system) that can power the entire system for 8 hours (for example for the duration of an astronomical night), you will need a battery with a capacity of at least:
10A (consumption per hour) x 8 (hours duration) = 80A
TIP: the EAGLE automatically switch off if the input voltage (measured at EAGLE’s input power connector) drops below 11.6V not only to protect the internal computer but also any devices that are powered through the EAGLE.
This also means that you have to consider the voltage drop caused by the power cables itself. Since, any length or size of electrical wire will have some resistance, if we assume a total current of 10A and the size of power cable of 1,5mm2, a power cable with 2.5 meter of length will create a voltage drop of 0,5V. So if you have a large power consumption, not only you have to have a proper power unit or battery, but also the appropriate power cable connecting your power source to the power IN port of the EAGLE. This is why the 14A power unit for the EAGLE is already 12.8V instead of 12V. If you want to use a field battery, we suggest you to use a power station with lithium battery like the EvoFlow RIVER that provides 13.3V cigarette plug output. If you have a standard deep-cycle 12V battery, you could use a 12.8V inverter or, if you can’t find this option, you can add a 220V inverter and then the 14A AC adapter, also if the latter solution is of course less power efficient.
A quick note related to cooled cameras that can be used in astrophotography EAGLE-powered telescopes with batteries. By using our laboratory instruments, we checked that some cooled cameras may have a very high power consumption peak (even 30A) for a very short time (less than half millisecond) only at the instant they’re powered on. This could lead to an overcurrent protection when the EAGLE is powered with a field battery. In this case, the way to correctly power these cooled cameras through your EAGLE-powered telescope with batteries in the field is to:
- check that the power cable from your camera to the EAGLE is not plugged to the camera
- turn the EAGLE on
- connect to EAGLE’s WiFi network and start Remote Desktop connection to see EAGLE Manager interface
- turn on the 12V port where you connected the camera power cable
- plug the power cable to your camera