Trotec EC060V - Shutter does not operate

[Martin72]

Hi,

A few weeks ago I´ve bought a used thermal camera from trotec, model EC060V.
It seems to work, but one thing is very irritating, couldn´t describe it better:
It seems, the cam display is in "persistence mode", parts of the former object you´ve examined will be "stored" and overlayed with the actual viewing...
In general, the handlig of the cam functions is complicated to me - So is it a "mode" which can be deactivated ?
Or is this simply a malfunction ??

(picture of the cam will be uploaded in the next days)

Martin

EDIT : Title changed

[Bill W]

Is the 'persistence' also inverted ?  That will be the calibration flag is stuck open.

If you hold your hand over the lens it should be fine for about a minute until the next 'calibration'.  You would expect to hear a click as the flag gets driven over.

Bill

[Fraser]

I carried out a teardown of the SATIR minIR80 some time ago. It is basically the same as your Trotec unit in terms of hardware.

https://www.eevblog.com/forum/thermal-imaging/thermal-camera-_teardown_-the-satir-minir80-by-fraser/

You can unscrew the lens completely to view the FFC shutter operation. As Bill_W states, this sounds like a problem with the FFC shutter either mechanically sticking open during the FFC event, or an issue with its driver electronics preventing it operating. If the FFC shutter remains open during an FFC event, the scene that the camera is viewing gets used to create the flat field image and the scene is likely anything but thermally Fiat ! The temperature measurement accuracy will also likely suffer as a result of such a fault.

Fraser

[Martin72]

Hi Guys,

Thanks for your posts, a few minutes ago I´ve tested it again, in the Livingroom.
Holding the cam in direction to the lamps on the ceiling, focussing it clear and sharp...looks good.
After a while, maybe it´s the minute, it stucks shortly (refresh? Can´t hear a sound), then you see what´s actual on the screen plus again the lamp but somekind of inverted.
And it stays, even when you turning to something else in the room.
After a while, maybe again the minute (must measure it), it vanish.
Hopefully it´s something which can be fixed...

Martin

[Fraser]

Those are the symptoms of a non functional or intermittent Flat Field Correction shutter.

You will need to investigate whether the shutter is jammed against its fully retracted end stop or some other mechanical hindrance has occurred. If you hear even the slightest click from the cameras lens area when it is trying to operate the FFC shutter, you will know that the solenoid drive is still operating. I would expect a sticky FFC shutter myself. You will need to dismantle the camera to inspect the very thin shutter flag and its drive system. See my teardown of the SATIR version for details.

FLIR cover the use of the FFC shutter here……

https://www.flir.co.uk/support-center/oem/what-calibration-terms-are-applied-in-the-camera-there-is-the-ffc-and-also-the-gain-calibration.-are-there-others-can-i-do-my-own-calibration/

Fraser

[Vipitis]

As said before, this sounds very much like the shutter flag not being moved at all. Do you have any shadows in any corners? That could mean the shutter is stuck half way.

I have experienced that with one of my cores and managed to repair it by simple adjusting a screw a bit so it could move again, cycled it a few times and carefully tightening the screw once again so it operated as expected.

If you can take the lens off take a look. There are different assemblies for shitter flags, so a possible repair might look different. Also depending on how severe the fault is.

[Martin72]

Another point (maybe) :
I don´t hear a thing, not a "click", nothing...
It would be a pity if this one couldn´t be fixed, in general it seems it is a "fast" one, moving objectives are displaying without remarkable delaying.
160x120, -20 to +250 degrees celsius aren´t that bad, even today.
And main thing (for me), it´s manual focussing...

Well, next Weekend I´ll tear it down and hopefully se what´s going on there.

Martin

[Spirit532]

Another point (maybe) :
I don´t hear a thing, not a "click", nothing...
It would be a pity if this one couldn´t be fixed, in general it seems it is a "fast" one, moving objectives are displaying without remarkable delaying.
160x120, -20 to +250 degrees celsius aren´t that bad, even today.
And main thing (for me), it´s manual focussing...

Well, next Weekend I´ll tear it down and hopefully se what´s going on there.

Martin

If you don't hear a click, then the shutter is stuck. Literally not moving.

[Martin72]

Hi...

Digging this thing out, starting with a stupid question:

"Unscrew" the objective, I can see the sensor of the cam - But how can I identify the shutter ?
I see a black area, nothing else...

[Martin72]

*Push*

Here a pic after releasing the objektive...
Where is the shutter ? 

[Fraser]

I did a tear down on this camera in its “Satir” branding here….

https://www.eevblog.com/forum/thermal-imaging/thermal-camera-_teardown_-the-satir-minir80-by-fraser/

Having looked at that thread, sadly I did not show the FFC flag operating but you can see its actuator solenoid in the lens block. If you operate the camera without a lens mounted you should see the FFC flag move across the face of the microbolometer when an FFC event occurs.

Fraser

[Fraser]

I have dug out my MinIR80 and will check the FFC flag operation for you. On charge now.

The flag will come in from one side of the microbolometer. It is not an iris type. It is only seen when brought into the optical path.

Fraser

[Fraser]

Whilst looking at the microbolometer window (lens removed for visibility), the FFC flag swings down from the top left with its arm pivot point located top right.

The flag is square in shape.

Fraser

[Fraser]

The FFC flag rotary solenoid is ringed in the attached picture. You can see the return spring that it acts against and that returns it to the parked position.

Fraser

[Martin72]

Thank you !
Will check this tomorrow.
Martin

[Fraser]

While you have got the camera apart, you might wish to gently clean the microbolometer window with a micro-fibre cloth and some IPA. Your looks particularly contaminated with dust / dirt.

Fraser

[Martin72]

Hi,

Will do and:
Teared apart now...

But following the plug to the pcb doesn´t make me happy, it seems someone has done some soldering to the pins...
So the issue was known I guess..

[Fraser]

The obvious tests are ….

1. Continuity check on FFC flag solenoid.
2. Check of FFC Flag solenoid with low voltage and a series current limiting resistor to avoid overcurrent. It will not need much, say 2V with a 1K resistor to start with and if no movement, creep up to 5V and see if the solenoid operates or at least looks like it’s trying to move. If not, yet it has good continuity, it is a mechanical fault. Either the flag mechanism is jammed or a detached magnet inside the solenoid.
3. If the solenoid is OK, monitor its input connections whilst the camera PCB is attached and running. The lack of a FFC event drive pulse to the solenoid would suggest a failure in the solenoid driver circuit or associated PCB traces.

Fraser

[Martin72]

Hi,

The DC-resistance of the Coil from the "Solenoid" is 6.9 Ohms....A supply with 100mA limited runs into its currentlimit without driving the solenoid.
The mechanic is manually free moveable, you can see the shutter then.

[Martin72]

The area around the plug, pics taken with andonstar microscope.

[Fraser]

In my comments on the Satir version that I dismantled, I said that some connectors appeared to have been hand soldered, and not with any great skill ! My pictures of the same PCB show similar questionable soldering on that same FFC solenoid PCB connector. I think that may be just the way these cameras were built.

I am a little surprised that the FFC solenoid did not operate at 100mA. It would be worth seeing if the drive pulse is present for the FFC solenoid. If it is, it suggests the issue may well reside inside the solenoid. the resistance you measures on the solenoid pins sounds about right to me. Hence my comment about including a resistor in series to limit current. I would have expected a current of less than 50mA to show activity in that solenoid but, if i am honest, I cannot remember the last time I tested one as all the ones I disagnosed had either corrosion induced issues or failed windings at the output pins.

Fraser

[Martin72]

Well, 5v/6.9Ohms are about 720mA so no wonder the supply shut down.
Solenoid...Is it a motor/servo which drives the shutter ?

[Fraser]

There should not be 5V across that solenoid. It should be powered in a controlled manner to avoid such excessive current. I would expect a switching transistor and current limiting resistor combination in the simplest configuration plus a diode to deal with back EMF. It may have a darlington driver in the adjacent IC marked 330h or it may be some dedicated solenoid driver IC.

[Fraser]

It is worth noting that the actuator is a limited rotation solenoid and not a motor. It contains a field coil and a shaft that is attached to a steel segment or even a magnet. It is like any other solenoid except that it rotates a shaft rather then producing a linear motion. It is effectively a low resistance coil, just like in a relay.

Fraser

[Martin72]

It may have a darlington driver in the adjacent IC marked 330h or it may be some dedicated solenoid driver IC.

It is exactly this IC (U10), the connections of the solenoid goes only to this one, more exactly the "plus" line, minus is gnd.
Tomorrow I´ll examine the area around the connector, trying to get a signal for the scope.