|C-7 Home Page C-7 News Consignment Library Products & Services Product Lines Order Search C7.com|
QUESTAR POWERGUIDE I DRIVE & CORRECTORThis accessory made by Questar has been discontinued and since replaced by the Powerguide II.
This article is provided as a courtesy by Company Seven for those customers who have helped to keep us in business.
The original internal Powerguide system of the 1980's and it's successor the Powerguide II are each an electronic regulated drive and corrector system powered by one 9 volt battery that allows the user to operate the Questar at a precise Sidereal or Lunar rate anywhere in the world - north or south hemispheres, completely independent of wall current or other external power sources. The Powerguide also provides the means to vary the rotation speed of the Right Ascension motor to make fine tracking adjustments. The internal Powerguide systems are arguably the most important innovation that has been developed for the Questar since its introduction.
Above page title: Questar logo used by the company through the 1980's into the 1990's.
Background The Questar 3-½ and Questar Seven telescope drive fork bases are furnished with a fork style drive base with a set of three very lightweight alloy legs. The legs thread into the drive base at two points on the side, and one at the bottom to form a tripod that is adjustable for latitude. This tripod permits the telescope to operate off of a table top. Alternatively, the telescope may be Pole Aligned atop an optional field tripod such as the Questar Tristand. The fork mount is normally provided with a 120 Volt A.C. (or 220 volt optional) motor system with an AC power cord. The AC cord plugs into a wall outlet and this starts the fork tracking at a Sidereal rate that permits accurate tracking of stars, planets and most other celestial objects as the Earth rotates. Since the motor is a non reversible synchronous motor one must specify either North or South Hemisphere when ordering this drive system. This basic arrangement is completely satisfactory for a person who operates the telescope for viewing only from one location that has A.C. power such as at a school, or on a home deck.
Powerguide I is the optional quartz crystal frequency regulated drive system for the Questar. A drive base equipped with Powerguide I incorporates a servo motor with drive corrector circuitry powered by a common alkaline 9 Volt D.C. battery housed in the hand-held controller. The endurance of this highly efficient system provides up to twenty four (24) hours of service and nearly double that time with a long life lithium 9 volt battery. This capability to operate from a battery eliminates the need to be located near an AC power source.
The hand-held control paddle controls all functions including the selection of drive rate (Sidereal or Lunar), fine speed correction changes of ±1.4 or 10X Sidereal. All control is done with the "On Off" switch and four (E-W-N-S-) push buttons; there are no switches on the drive base - all is on the hand paddle that plugs into the bottom of the base. An internal Quartz reference circuit continuously checks motor speed every 0.6 Arc Sec. and adjusts it as necessary. But the most important aspects of this option are that it frees a person to travel around the world, to the North or South Hemisphere independent of external power supplies.
The development of the 9 volt Powerguide systems was accompanied by the introduction of an optional Motorized Declination Assembly for the Questar 3-½ Fork. This accessory includes a Declination Hand Control wheel that replaces the original, and the Motor and Support Frame that is attached onto the Fork Tine meshing with the new Declination Hand Control wheel. The only Questar 3-½ Motorized Declination Drive and the Questar Seven Motorized Declination Drive options are for use only with those Questar Fork Mounts that incorporate the Powerguide II drive and control system. There is no longer any Declination Motor made that is compatible with this original Powerguide system.
Right: Questar Powerguide I Control Panel and Hand Control. The rectangular black plastic lid covers the battery compartment. Controls left to right: Power light, switches for On-Off, N-S, and input for 12 vdc, outputs for optional illuminated reticle and Declination Motor (110,214 bytes).
Set up and Operation:
Right: Questar Powerguide I hand held control paddle (85,603 bytes).
Company Seven recommends this be used as a fine positioning aid, it is not designed as a slewing motor to drive the telescope back and forth across large areas of the sky.
Furthermore, if you do plan to store away the telescope for extended periods then we recommend removing the battery, or storing it separately within a Zip-Loc style bag. In this way if the battery leaks it will not corrode the internal portions of the telescope base. When storing the telescope over long periods, particularly in humid climates, then it is a good practice to store the telescope with desiccant in the carrying case. Also periodically turn on the Powerguide I drive and allow the motor to run for several hours, this will help to prevent oxidation from accumulating on the motor brushes thereby increasing reliability. Do not be concerned about running the Powerguide I for too long, we have tested the motor of one unit by running it continuously for more than two years (>17,530 hours!) before we finally turned off its power supply.
Powerguide I Drive Specifications*
We invite you to visit our showroom near Washington, D.C. to see a Questar first hand. Or contact us by E-Mail to email@example.com, or by telephone at 301-953-2000. The showroom is open Monday to Friday 11 am to 6 pm, Saturday 11 am to 5 pm. We are closed on Sundays, on U.S. Holidays, and from 25 December through 1 January inclusive.
Contents Copyright 1994-2006 Company Seven All Rights Reserved