Looking for info/help on 4 wire DC motor - Page 1
Forum section: electronics / general

author: Sixuno
author_rank: Newbie
timestamp: May 24, 2012, 12:43:48 am
content: Hello all!I'm looking for information regarding a 4 wire dc motor that I have. I'm not sure if it's considered a stepper motor or not.All I know is the part number stamped on the side ( VG02E005-0001 ).This motor is one of four used to control the movement of a camera inside a seeker head used in an obsolete guidance section. I'm looking to make some type of simple circuit to manually control the motors inside the seeker. My goal is to make a static display of the seeker head for our unit, more of a gee wiz memento to remember the weapon as its retired.I'm envisioning controlling the camera gimbal inside by means of a analog joystick of some sorts or even two potentiometers.I can follow simple schematics for the most part, but I'm just a tinkerer in general so be easy on meIf someone can design some simple control, I can send you a few of these motors for free for helping.

author: PeterG
author_rank: Frequent Contributor
timestamp: May 24, 2012, 01:51:29 am
content: Looks like a Stepper Motor. Have a look at these sites for info on there operation.http://en.wikipedia.org/wiki/Stepper_motorhttp://www.solarbotics.net/library/pdflib/pdf/motorbas.pdfRegards

author: free_electron
author_rank: Super Contributor
timestamp: May 24, 2012, 04:51:27 am
content: Steppers would not be precise enough for such an app. Looks more like a brushless dc motor with a centertap.Do a measurement. Take one wire and measure the resistance to the three others.If you find one wire where all three others give the same reading you have a star configuration with centertap.If you only find 1 other wire that connects then you have a stepper.

author: PA0PBZ
author_rank: Super Contributor
timestamp: May 24, 2012, 08:32:01 am
content: Searching on google makes me think it's not a motor at all but a variable resistorhttp://www.wbaviation.com/nsndetail.cfm?NIIN=013902497&pn=89684Looks like the motor is VG02E004-0001:http://www.wbparts.com/rfq/1420-01-388-6288.htmlAnyway... Don't try to power it up before you are sure, the magical smoke might escape

author: PeterG
author_rank: Frequent Contributor
timestamp: May 24, 2012, 08:58:31 am
content: Hmmm.... According to this site, VG02E005-0001 is for a component for a Guided Missile.http://www.parttarget.com/1420-01-388-6288_1420013886288_VG021002-001.htmlJust try getting that through customs LOLRegards

author: amyk
author_rank: Super Contributor
timestamp: May 24, 2012, 10:18:44 am
content: Quote from: PeterG on May 24, 2012, 08:58:31 amHe did say "guidance section" and "weapon" in the original post...Also found some more info the says it's a 10k rotary pot manufactured by Boeing that costs $2500+.To figure out the connections, you should measure the resistances across the wires while turning the shaft.

author: Sixuno
author_rank: Newbie
timestamp: May 24, 2012, 11:02:15 am
content: Yea, I'm sure this all sounds crazy to some but with the all up round weapon retiring, all this excess stuff to support it goes to the trash or gets shredded and recycled for the most part.I'll do the measurements when I get to work and report back the findings soon.

author: Sixuno
author_rank: Newbie
timestamp: May 24, 2012, 12:49:49 pm
content: Received the wiring schematic today that covers entire unit.Hope this is one step closer to making them workI'll still take the dmm to each lead.

author: free_electron
author_rank: Super Contributor
timestamp: May 24, 2012, 02:51:22 pm
content: From that schematic and the colors on your picture it looks like you only have the pickoff assembly... The motor itself is missing.

author: Sixuno
author_rank: Newbie
timestamp: May 24, 2012, 04:03:10 pm
content: Negative, I pulled the entire camera gimbal out of a working guidance section.This pic should give you an idea of how it mounts. The camera mounts directly to one motor and a stabilizer motor on the other side.When you apply power to the stabilizer motor, the hollow shaft seems to align to a preset magnetic field. I think 2 wire motor just keeps the whole camera stable and centered so the heavy camera in the middle doesn’t smack the side of the frame.

author: codeboy2k
author_rank: Super Contributor
timestamp: May 24, 2012, 06:38:57 pm
content: If it's a seeker, won't that be an IR camera inside it? If your goal is to control the camera with a joystick, you probably want a visible spectrum camera. You can swap it out for a normal camera on the gimbals, but you might have also gained a nice IR camera.Good for finding hot spots on circuit boards, depending on it's resolution (which might not be too high, if it's designed to be at the nose of a missile), it only has to find the heat of a target and lock on.

author: SeanB
author_rank: Super Contributor
timestamp: May 24, 2012, 08:40:13 pm
content: Seekers generaly do not use a camera, most use a IR detector that is kept at cryogenic temperatures, and use the spin stabilisation of the missile to provide error information either with a chopper vane or a moving head to track the target. Only the "made for TV" missiles use a camera, mostly because they are designed for hitting a ground target either designated by a laser painter or by being guided onto the target by a terrain recognition computer.Nice thing was that the high pressure nitrogen that was used to provide the actuator operation was also used as the cooling system for the sensor, as reducing the pressure down to operating pressure meant it came out of the regulator at low temperature. So what if it only provided 5 minutes of cooling......... It only needed 45 seconds in most cases.

author: Sixuno
author_rank: Newbie
timestamp: May 24, 2012, 09:21:47 pm
content: Seeker is a general term we call the nose/camera portion of the overall system. This one doesn't actually track a target automatically, just gives the weapons officer the ability to fly it to target while using the IR/tv camera. While I think it would be awesome to enable the video somehow that would be way above my ability. Their is a small IR camera/sensor inside and the part number listed on that unit comes up costing $38k. I guess having this technology 15 years ago cost a bit more to produce then now. I don't think the resolution would compare to todays technology.Google AGM-130 and you can see what these came off of.SeanB is correct on cooling it. This unit holds a 6K PSI Argon tank to keep everything cold.The image attached shows the IR sensor( bottom right), that little nub at the bottom is the cut stainless line that connects to the Argon regulator.I have both IR and TV versions to tinker with. But my main goal is to get the camera gimbal moving by some crude method.I hope I did this right.Rotating shaft clockwise only and measuring with a Fluke 1587 on auto range.black - red constant 10.64k ohmsblack - yellow starts 1.0 ohms to 15.49k ohms, starts 1.0, climbs to 15.49k then restarts at 1.0black - green 2.823k to 5.453k, it starts 2.823k climbs to 5.453k then lowers back to starting 2.823 (like a sine wave)green to yellow 9.62 to 18.90k, hits 18.90 then resets to 9.62green to red constant 5.471kred to yellow 1.0 to 24.02k, starts 1.0, climbs to 24.02 then restarts at 1.0