Appendix A: Determining Power Supply
Requirement Examples
EXAMPLE SETUP #1 – SIMPLE SETUP
- Celestron 8" Dew Heater Ring connected to dew heater port #1
Max current draw of 8" Dew Heater Ring = 1.7A
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Max power required for 8" Dew Heater Ring = 12V x 1.7A
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= 20.4W
- Celestron Advanced VX EQ mount connected to power port #2
Max current draw for Advanced VX EQ mount when slewing
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at highest speed = approximately 2.0A
Max power required for Advanced VX when slewing at max
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speed = 12V x 2.0A = 24.0W
- Smartphone connected to USB port #1 (for purposes of charging
smartphone)
Keep in mind that the USB ports supply 5V DC (which is the
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USB standard), while all the other ports supply 12V DC
Smartphone current draw when charging = 2.1A
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Power required for smartphone when charging = 5V x 2.1A
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= 10.5W
In this example, the total max power required by the controller would
be about 55W.
- If you have access to AC power, then the Celestron's AC Adapter-
5A can handle up to 60W and would be a good choice for powering
the controller.
- For portable setups, the Celestron PowerTank Lithium Pro can
provide up to 120W power (10A max current), so it would work well
with this example setup.
Since the battery capacity of the PowerTank Lithium Pro is
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158.7 Watt-hours, and the controller will use approximately
55 watts power, the battery should last almost 3 hours when
all the devices are drawing full power. Suppose you are using
auto smart control for the dew heater ring. In that case, you
can expect the battery to last significantly longer since the
ring will probably not be operating continuously at max power.
Similarly, if you are not repeatedly slewing the telescope at its
highest speed, then the power consumed by the mount will
be much less, further extending battery charge life.
EXAMPLE SETUP #2 – IMAGING SETUP
- Celestron 11" Dew Heater Ring connected to dew heater port #1
Max current draw of 11" Dew Heater Ring = 2.5A
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Max power required for 11" Dew Heater Ring = 12V x 2.5A
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= 30.0W
- Other manufacturer's heating band/strip for guidescope connected
to dew heater port #2
Max current draw for heating band/strip for guidescope =
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12
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approximately 1.0A
Max power required for heating band/strip for guidescope =
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12V x 1.0A = 12.0W
- Celestron CGX EQ mount connected to power port #2
Max current draw for CGX EQ mount when slewing at highest
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speed = approximately 3.0A
Max power required for CGX EQ mount when slewing at max
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speed = 12V x 3.0A = 36.0W
- Cooled CMOS camera connected to USB port #1
Keep in mind that the USB ports supply 5V DC (the USB
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standard), while all the other ports supply 12V DC
Cooled CMOS camera current draw = 0.3A
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Power required for cooled CMOS camera = 5V x 0.3A =
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1.5W
- Cooled CMOS camera's thermoelectric cooler (TEC) connected
to power port #3
Max current draw for cooled CMOS camera's thermoelectric
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cooler (TEC) = 3.0A
Max
power
required
for
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thermoelectric cooler (TEC) = 12V x 3.0A = 36.0W
- CMOS guide camera connected to USB port #2
Keep in mind that the USB ports supply 5V DC (the USB
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standard), while all the other ports supply 12V DC
CMOS guide camera current draw = 0.3A
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Power required for CMOS guide camera = 5V x 0.3A = 1.5W
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- Celestron Focus Motor connected to USB port #3
Keep in mind that the USB ports supply 5V DC (the USB
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standard), while all the other ports supply 12V DC
Max current draw for Celestron Focus Motor = approximately
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1.0A
Max power required for Celestron Focus Motor = 5V x 1.0A
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= 5.0W
In this example, the total max power required by the controller would
be about 122W.
- Since the max power required by the controller is greater than
120W (10A max current), you can only use the XT60 power input
jack to power the controller.
- If you have access to AC power, you could use a high-power AC-
to-DC power supply to power the controller.
If the output voltage for the AC-to-DC power supply is
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variable, make sure to set it to 12V before connecting it to
the controller.
- For portable setups, we recommend finding a 12V DC "marine
battery" or other portable 12V DC battery capable of providing over
122W power.
If you plan to image all night (8 hours) with this setup, you
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would need a marine battery with a capacity of 122W x 8
hours = 976 Watt-hours (i.e. approximately 82 amp-hours
@ 12V DC).
cooled
CMOS
camera's