D
Don Bruder
Guest
I've got the lens assembly out of a defunct camcorder (brand, type,
basically *EVERYTHING* about it unknown, other than it's pretty hard to
not know what it is) that's in good shape, so I'm wanting to use in a
project. Unfortunately, this lens unit came out of a "junkbox"
situation, so I have *NO* idea what the driving circuitry looked like -
I've just got two two-pin plugs and a four-pin plug dangling in space.
Oh, and the two-pin plug for what is quite obviously intended to be used
as a "Hey, stupid! You've already cranked the focus knob as far as it
can go, so I'm shutting things down" limit switch. The only identifying
markings on the entire unit are on one of the motors (Focus motor,
labeled "Tokyo Micro - P1111") and the lens shroud ("Made in Japan")
It has three motors on it, one for focus, one for zoom, and one driving
the aperture. The ones for focus and zoom are conventional two-wire
"wants DC of the right polarity for the desired rotational direction"
units. They behave exactly as expected.
The third motor, controlling the aperture, is wired - and under testing,
behaves - strangely. There are no markings of any kind on this motor -
if there ever were, they have either faded, eroded, or otherwise been
obliterated.
From it come four wires: brown, red, orange, and yellow, leading to a
four-pin plug that, "reading" left to right, puts them in the same order
listed.
On the motor, there are two columns of four solder pads, one on each
side of the shaft. A "picture" follows:
o Empty Empty o
o Red Yellow o
o Brown Orange o
o Empty Empty o
First thought: Some sort of stepper motor?
(FWIW: "Used" shaft rotation is approximately 1/3 turn before hitting
mechanical stops at either end of the range, and is spring-returned to
the "full-closed" - counterclockwise - position when no power is applied)
Take a SWAG that Brown is probably ground and the other three wires are
three phases of a stepper motor. Test this theory by hooking brown to
ground, and hitting each other wire with +5 volts. Results:
Red - Rotate clockwise to stop (full open aperture)
Orange - No reaction
Yellow - No reaction
OK, that sorta panned out, but not really...
Let's see... Yellow as ground?
Brown - No reaction
Red - No reaction
Orange - Rotate clockwise to stop
OK, I've established that either red/brown or orange/yellow swing it to
the stop when Brown/Yellow respectively are treated as ground and +5V is
applied to the other wire. At least it's SOMETHING, right?
Reverse polarity by putting the +5V on the brown or yellow, and use the
red or oragne as ground, and try it again.
Results are identical to those already noted - specifically, red/brown
and yellow/orange both cause it to swing to the full-open position.
Red "hot" and Orange "ground" does nothing visible, as does the reversed
polarity version.
Red/Yellow does nothing for either polarity.
Orange/Brown likewise does nothing regardless of polarity.
Seemingly, polarity is of no interest. That means it pretty much has to
be a stepper of some sort. Doesn't it?!? Or perhaps this thing is a
round solenoid???
Can't be... The whole point of an aperture in photography is to offer an
adjustably-sized hole for the light to go through - It's NOT an "all or
nothing" situation - that's what the shutter is for. A typical camera
usually uses about 6-10 preset "f-Stop" values, although the mechanics
of the aperture are almost always such that an effectively infinite
number of stops COULD be used if so desired. Which takes me right back
to the stepper motor concept - By properly stepping, all the f-Stops
that are likely to be desired/functional for the camera in question
should be achievable. But I haven't ever encountered a stepper motor
that behaves like this one. (if that's indeed what this is) Besides...
every stepper motor I've encountered "clicks" to each step - This unit,
when using a snippet of wire or similar "pusher" so I can get to it,
rotates freely other than the spring - no noticable resistance or
cogging - just a smooth, very-little-effort sweep from one stop to the
other.
Similarly, I don't think it's a case of "apply the right juice, get the
desired f-Stop", since using a pot wired into the mix doesn't reliably
"repeat" - I put a 1K pot in series with the hot wire, and until the
resistance drops to a certain point, there's no reaction, and once past
that point, the aperture doesn't repeatably open to the same degree for
any given setting. Even more important, it "jitters" a bit, like it
can't decide where it ought to be - Which makes it TOTALLY unsuitable
for photo/video work. For this application, it needs to go to "point X"
and stay there, rock solid, until specifically told to go to some other
point. This thing "wiggles all over the place" if the lens assembly is
bumped, moved, etc while power is applied - Not exactly "go to point X
and stay there" behavior, and particularly unwelcome in a camera that's
likely to be moving to follow the action it's looking at.
All of this combines to leave me right back where I started: Wondering
how to drive this motor so I can use the aperture of this lens in a way
that's at least somewhat like what was intended.
So, I turn to the group in hopes that somebody reading has a clue what
kind of motor I'm messing with, and how to drive it. Anybody?
--
Don Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004.
Short form: I'm trashing EVERY E-mail that doesn't contain a password in the
subject unless it comes from a "whitelisted" (pre-approved by me) address.
See <http://www.sonic.net/~dakidd/main/contact.html> for full details.
basically *EVERYTHING* about it unknown, other than it's pretty hard to
not know what it is) that's in good shape, so I'm wanting to use in a
project. Unfortunately, this lens unit came out of a "junkbox"
situation, so I have *NO* idea what the driving circuitry looked like -
I've just got two two-pin plugs and a four-pin plug dangling in space.
Oh, and the two-pin plug for what is quite obviously intended to be used
as a "Hey, stupid! You've already cranked the focus knob as far as it
can go, so I'm shutting things down" limit switch. The only identifying
markings on the entire unit are on one of the motors (Focus motor,
labeled "Tokyo Micro - P1111") and the lens shroud ("Made in Japan")
It has three motors on it, one for focus, one for zoom, and one driving
the aperture. The ones for focus and zoom are conventional two-wire
"wants DC of the right polarity for the desired rotational direction"
units. They behave exactly as expected.
The third motor, controlling the aperture, is wired - and under testing,
behaves - strangely. There are no markings of any kind on this motor -
if there ever were, they have either faded, eroded, or otherwise been
obliterated.
From it come four wires: brown, red, orange, and yellow, leading to a
four-pin plug that, "reading" left to right, puts them in the same order
listed.
On the motor, there are two columns of four solder pads, one on each
side of the shaft. A "picture" follows:
o Empty Empty o
o Red Yellow o
o Brown Orange o
o Empty Empty o
First thought: Some sort of stepper motor?
(FWIW: "Used" shaft rotation is approximately 1/3 turn before hitting
mechanical stops at either end of the range, and is spring-returned to
the "full-closed" - counterclockwise - position when no power is applied)
Take a SWAG that Brown is probably ground and the other three wires are
three phases of a stepper motor. Test this theory by hooking brown to
ground, and hitting each other wire with +5 volts. Results:
Red - Rotate clockwise to stop (full open aperture)
Orange - No reaction
Yellow - No reaction
OK, that sorta panned out, but not really...
Let's see... Yellow as ground?
Brown - No reaction
Red - No reaction
Orange - Rotate clockwise to stop
OK, I've established that either red/brown or orange/yellow swing it to
the stop when Brown/Yellow respectively are treated as ground and +5V is
applied to the other wire. At least it's SOMETHING, right?
Reverse polarity by putting the +5V on the brown or yellow, and use the
red or oragne as ground, and try it again.
Results are identical to those already noted - specifically, red/brown
and yellow/orange both cause it to swing to the full-open position.
Red "hot" and Orange "ground" does nothing visible, as does the reversed
polarity version.
Red/Yellow does nothing for either polarity.
Orange/Brown likewise does nothing regardless of polarity.
Seemingly, polarity is of no interest. That means it pretty much has to
be a stepper of some sort. Doesn't it?!? Or perhaps this thing is a
round solenoid???
Can't be... The whole point of an aperture in photography is to offer an
adjustably-sized hole for the light to go through - It's NOT an "all or
nothing" situation - that's what the shutter is for. A typical camera
usually uses about 6-10 preset "f-Stop" values, although the mechanics
of the aperture are almost always such that an effectively infinite
number of stops COULD be used if so desired. Which takes me right back
to the stepper motor concept - By properly stepping, all the f-Stops
that are likely to be desired/functional for the camera in question
should be achievable. But I haven't ever encountered a stepper motor
that behaves like this one. (if that's indeed what this is) Besides...
every stepper motor I've encountered "clicks" to each step - This unit,
when using a snippet of wire or similar "pusher" so I can get to it,
rotates freely other than the spring - no noticable resistance or
cogging - just a smooth, very-little-effort sweep from one stop to the
other.
Similarly, I don't think it's a case of "apply the right juice, get the
desired f-Stop", since using a pot wired into the mix doesn't reliably
"repeat" - I put a 1K pot in series with the hot wire, and until the
resistance drops to a certain point, there's no reaction, and once past
that point, the aperture doesn't repeatably open to the same degree for
any given setting. Even more important, it "jitters" a bit, like it
can't decide where it ought to be - Which makes it TOTALLY unsuitable
for photo/video work. For this application, it needs to go to "point X"
and stay there, rock solid, until specifically told to go to some other
point. This thing "wiggles all over the place" if the lens assembly is
bumped, moved, etc while power is applied - Not exactly "go to point X
and stay there" behavior, and particularly unwelcome in a camera that's
likely to be moving to follow the action it's looking at.
All of this combines to leave me right back where I started: Wondering
how to drive this motor so I can use the aperture of this lens in a way
that's at least somewhat like what was intended.
So, I turn to the group in hopes that somebody reading has a clue what
kind of motor I'm messing with, and how to drive it. Anybody?
--
Don Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004.
Short form: I'm trashing EVERY E-mail that doesn't contain a password in the
subject unless it comes from a "whitelisted" (pre-approved by me) address.
See <http://www.sonic.net/~dakidd/main/contact.html> for full details.