Power Supplies & Accessories


If you are using household current, it must be converted to between 11.5 and 18 volts DC (12.5V to 16V recommended), and your power supply must be rated for the amp requirements of your system: If your system draws 3 amps, then your power supply must be rated for at least 3 amps. We recommend a 5 amp rating as a minimum for all of our current GTO mounts. Again, it is a good idea to have the mount operate on a dedicated power supply and power your accessories from an additional supply. It isn't that your Astro-Physics mount is a power-hungry monster.  It's that other accessories - especially dew heaters - can really cause some major short term voltage fluctuations and can draw significant amounts of current.

In extremely cold climates, it is recommended that you keep your power supply in a heated environment when not in use or warm it up a bit before turning it on. Once it is operating, it will generate enough internal heat to function at full strength well below its rated lowest temperature. Turning the unit on when its components are below the rated temperature is not recommended. Keep in mind that power supplies are not really designed for outdoor use. Fortunately, we don't observe in the rain, so it normally isn't a problem for us to use these devices outdoors. However, keep in mind that power supplies are not waterproof or double insulated. They should not be left outside exposed to the elements. For safety, we recommend plugging these units into a GFCI protected circuit.

We recommend, as a minimum, that a 12-volt, 12-amp hour rechargeable battery be used for all of our mounts.

If you are planning to use your own battery, it is recommended that a deep-cycle battery be used. The battery should be dedicated to the mount for optimum performance. Accessories should be powered from an additional battery whenever possible. Please see the Servo Drive manual that came with your mount or view the current GTOCP4 Servo Drive manual on the Technical Support page of our website for additional information.


13.8-Volt, 5-Amp Regulated Power Supply with Cigarette Lighter Receptacle (PS138V5A)

For individuals wanting to use household current, we have a 115 volt AC converter that puts out 13.8V DC at 5 amps. This voltage-regulated unit should serve most users' needs. It has protection circuitry to guard your valuable equipment. It is not recommended for extremely cold climates where a higher voltage is needed for satisfactory mount performance. If you are powering several devices like dew heaters, cameras and motorized focusers, we would advise you to have one converter dedicated to the mount only, and one or more for your accessories.

Input: 105 to 125 volt 60 Hz AC
Output: 13.8 (+/- 0.3) volt DC; 5 amp continuous, 7 amp peak
Output Ripple: 150 mV RMS
Operating Temp. 32° F (0° C) to 104° F (40° C)
3 1/4 H x 4 7/8 W x 7 1/4 D; 5 1/2 lb.

For those of you travelling internationally: According to Pyramid, you MUST transform 220 volt 50 Hz current to 115 volts before using this power supply. They say it will operate at the proper voltage at either 50 or 60 Hz, but at 50 Hz AC input, the unit will provide slightly less amperage. We have not tested this assertion from Pyramid.

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25 Amp Variable Volt Power Supply (PSVPW25A)

This 25 amp power supply offers the advantage of variable voltage so that you can dial up 15 volts and keep the mount motors happy when they are powering heavy loads or when they are being used in cold climates.  

The Powerwerx dual metered digital power supply is designed to supply 25 Amps continuous and 28 Amps surge. It features user variable output (5-16 VDC) by adjusting the front mounted knob, or fixed 14.1 VDC output. Power output is through the rear mounted 1/4" binding posts, using ring terminal connects (available as part of our CP4 power cable set), banana plugs or compression connectors. 

We always recommend that the mount have its own power supply and that other accessories be on a separate supply.  Use one for the mount and one for the accessories.   This power supply will allow you to set voltage at 12 volts instead of 13.8 volts if sensitive CCD cameras are being used. 

  • LED display – volts and amps
  • DC output – fixed 14.1 and adjustable 5-16 volts
  • Output amperage – 25 amp continuous and 28 amp peak
  • Input voltage – user selectable 115 VAC or 230 VAC
  • Fan: Quiet internal cooling fan
  • Rear mounted ¼” binding posts
  • Compact – 6.1” x 5” x 2.5” (155 mm x 127 mm x 64 mm)
  • Weight: 3.7 lbs. (59 oz.)
  • Meets CE/LVD standard for export to EU

The PSVPW25A power supply is cooled by convection and forced air cooling (normal airflow around the power supply in combination with a temperature controlled fan to improve cooling at higher levels of use). The fan is temperature activated and the speed is controlled by a sensor. When the temperature rises, the fan speed increases

Important note:

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DC Inline Watt Meter and Power Analyzer (CABPPWM)

This easy to use meter is ideal for monitoring eight electrical parameters that are essential to electric power safety and performance: Amps, Volts, Watts, Amp-hours, Watt-hours, Peak Amps, Minimum Volts (Sag), and Peak Watts. It connects via Anderson Powerpoles and can be easily installed inline on the CP4 power cable.  Its high contrast blue backlit display and auto reset feature make this a very useful watt meter and power analyzer. 


  • Amps (Current) & Peak Amps – Peak amps show if excessive amps are being drawn:  The Amps (A) value displayed shows the average current over the last screen refresh. The Peak Amps value (Ap) displays the maximum current drawn since the meter’s last startup.
  • Voltage & Minimum Volts – Confirm that the desired voltage is being delivered & if battery is low voltage:  The displayed Volts (V) value is the average voltage from the last screen refresh. The displayed Minimum Volts (Vm) value is the minimum voltage or “sag” measured on the source side, since the meter’s last startup.
  • Amp-hours (Charge) – Estimate how much battery will be needed:  The displayed value is the total charge delivered in Amp-hours since the meter’s last startup. It is measured from the load side for the most accurate results.


  • Voltage: 0 ~ 60V, 0.01 V resolution (5 to 60V without optional auxiliary power connector)
  • Amps: 1 ~ 130A, 0.01 A resolution (50A continuous, 130A peak)
  • Watts: 0 ~ 7800W, 0.1 W resolution
  • Amp-hours: 0 ~ 65Ah, 0.001 Ah resolution
  • Watt-hours: 0 ~ 6554Wh, 0.1 Wh resolution
  • Display: High-contrast blue backlit LCD display
  • Size: 3.3 x 1.7 x 1.0" (85 x 42 x 24mm)
  • Weight: 0.18 lbs. (82 g)
  • Warranty: 1 Year Limited Warranty

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CP4 Powerpoles to Alligator Clips (CABPPAL)

Expand the versatility of your mount.  This alligator clip power cable adapter enables you to power your mount from a car or a deep-cycle marine battery (deep-cycle batteries are recommended).  Equipped with Anderson Powerpoles, as used with the CP4 power cable, you can connect directly to battery terminals.  Includes 7.5 amp in line ATC fuse.

Don't feel restrained...grab your mount and a battery and head to a dark sky site!

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Kendrick Alligator Clips (KDRALL)

This handy adapter by Kendrick Astro Instruments enables you to power your mount from a car or a deep-cycle marine battery (deep-cycle batteries are recommended). Equipped with a female cigarette socket receptacle, you can connect directly to battery terminals with the power cable included with your Astro-Physics mount. Includes 7.5 amp in line ATC fuse.

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This page was last modified: February 28, 2018

Astro-Physics, Inc.
11250 Forest Hills Road, Machesney Park, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847