Appendix A: Determining Power Supply
Requirement Examples
EXAMPLE SETUP #1
- 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 = 20.4W
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- Celestron Advanced VX EQ mount connected to power port #2
Max current draw for Advanced VX EQ mount when slewing at
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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
In this example, the total max power required by the controller would
be about 48W.
- If you have access to AC power, the Celestron AC Adapter-5A,
which can handle up to 60W, 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.
The battery capacity of the PowerTank Lithium Pro is 158.7 Watt-
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hours. The controller uses approximately 48 watts power per
hour. Therefore, the battery will last over 3 hours in this example.
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 operate 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
- 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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approximately 1.0A
Max power required for heating band/strip for guidescope = 12V
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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
In this example, the total max power required by the controller would
be about 78W.
- If you have access to AC power, a high-power AC-to-DC power
supply will work well for powering the controller. Celestron's AC
Adapter-5A would not work since its maximum is 60W.
If the AC-to-DC power supply voltage is variable, make sure to set
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it to 12V before connecting it to the controller. Also, remember
that the power input jack is tip positive.
- For portable setups, the Celestron PowerTank Lithium Pro can
provide up to 120W power (10A max current), so it would work with
this example setup. However, it may not have enough power storage
capacity for your entire observing session.
The battery capacity of the PowerTank Lithium Pro is 158.7
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Watt-hours. The controller will use approximately 78 watts
power per hour. Therefore, the battery should last about 2
hours in this example. 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 operate 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.
- For portable setups that you plan to run all night, we recommend
a 12V DC "marine battery" or other portable 12V DC battery with
high power storage capacity.
If you plan to image all night (8 hours) with this setup, you would
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need a marine battery with a capacity of 78W x 8 hours = 624
Watt-hours (i.e., approximately 52 amp-hours @ 12V DC).
ENGLISH |
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