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 Posted: Thursday Apr 26th, 2007 09:13 pm
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A re-vamp is now urgently required.

- needs customer light level adjustment NOT from a POT has to be able to be achieved from Comfig.

- the actual LLsensor HAS to be supplied housed in some form - its no good just supplying the sensor

- would be nice to have lux level feedback

- we also add a feed back loop ino our service schedule to tell us when the sensor is not working - this could be a standard response.



 Posted: Saturday May 5th, 2007 10:20 am
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Any other suggestions.

Dont forget we use a single light sensor for multiple applications not just direct comfort so the price could be higher.

Also I have always had an issue with the mounting of the sensor. Its NO GOOD just supplying the sensor it needs to be housed PROPERLY.      Nigel .......

 

So any chance of an update to the light sensor!

 

 



 Posted: Saturday May 5th, 2007 10:33 am
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ident
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We produced the LSM some years ago but have only sold about 10 - 20 sets per year
Due to the problems encountered by some users because of hysteresis and the difficulty of completely preventing some multiple switching, we have decided not to continue to supply it.

For those who need this type of product there are other alternatives eg from Velleman see
http://www.velleman.be/ot/en/product/view/?id=344193
which has been used by one of the users on the group with success


For UK the dealers for this can be found at
http://www.velleman.be/dealer/search/?step=3&cid=57&did=1



 Posted: Saturday May 5th, 2007 10:47 am
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Perhaps the reason why you only sold so few is because of the reasons i have outlined!

 



 Posted: Sunday May 6th, 2007 02:17 am
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ident
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Perhaps, but nevertheless we have to focus our efforts on products that are essential for the product and cannot be obtained elsewhere. If there are better alternatives by other manufacturers then we should spend our time on other more important products, (some of which you have been asking for). The reality is, our resources are limited - the more time we spend on something, the less time we have for other products.



 Posted: Tuesday May 8th, 2007 10:57 am
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I will look into this matter for the UK and hope to post a new message in a week or so.  I will confer with other distributors in the first instance.

Noted about the packing & lux sensing. 

I am surprised so few LSMs were sold as the light / dark event is certainly useful perhaps people have been using alternatives for somewhile.

Nigel



 Posted: Thursday May 10th, 2007 01:52 pm
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Yep would agree dusk/dawn detection is a good starting point and I have typically used mains based units with relay outputs to do this. Seem to be better built than LSM and more reliable long term. Perhaps that is why you do not see to many modules sold.

Lux level would be better however because the thresholds for external lighting are different to those needed to operate internal lighting. Back to needing easy to implement analogue I/F's into comfort. Could make do with 0-3V that we have now but would need buffer/scaling amp to light sensor.



 Posted: Saturday May 12th, 2007 03:48 am
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One of the features we are adding in future would be sunrise/sunset settings in Comfort and Comfigurator and automatic time change for Daylight savings, so that may meet part of the needs for the LSM.

Update.
Sunrise and Sunset Times, Daylight saving automatic time changes, testing for Night time has been introduced in Firmware 5.121 and Comfigurator 3, see http://www.comfortforums.com/forum20/1004.html

Last edited on Sunday Oct 31st, 2010 02:44 pm by



 Posted: Saturday May 12th, 2007 09:49 pm
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ndh
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Ref the manual 1.0.2

Page 2 mentions:

'supplied 10K Ohm resistor'

'This resistor matches the resistance of the Light Sensor at normal light conditions'

Page 4 indicates LDR will have a resistance circa 75K

Is there an error here?

Page 2 also mentions:

'check the wire resistance does not exceed 100 ohms'.

What to do if this is exceed please?

I have a user where the cable is long and the on/off point is barely achievable.



 Posted: Sunday May 13th, 2007 02:05 am
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The resistance in page 4 is specified at a certain light level. Hence 10K can be acieved under "normal" light levels
How far is the LSM cable and what wire are you using. Normal alarm cable is 8 ohms per 100 m, so 100 ohms would be 1.2 KM.  There may be other problems with the wiring

Try reducing the series resistance to achieve hogher sensitiviy/gain



 Posted: Sunday May 13th, 2007 11:39 am
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garym999
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The gregorian clock function will be handy but when you are talking lighting control, it does not map to local weather (light) conditions. So a Lux level sensor would still be handy.

Nigel, The implied 75K on page 4 is the approximate resistance at 10 Lux... (ref datasheet). The resistance range just shows how inaccurate these sensors are.

The effect of the sensor wiring (100R) is going to be minimal.

In practice I would suspect external interference or induced voltages in the cable. Is the sensor cable running along side mains cables etc. If the cable is screened this should be less of a problem.

To mitigate this I would remote mount the whole PCB assy in a IP rated clear case and ensure that it is sealed around the cable entry correctly.

Alternatilvely use a mains based dusk/dawn relay. It might need to be modified to produce a set of volt free contacts but I have found them easy to implement and have suitable hysterisis built in (30secs +) so you do not need any special coding to ensure reliable operation. Oh and it is in a weather proof housing with proper conformal coatings to protect the PCB and sensor.



 Posted: Sunday May 13th, 2007 12:13 pm
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garym999
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I have the Velleman MK125 kit here on the bench.

It has built in hysterisis but it is implemented rather crudely. It takes about 5 seconds for a switch over but once this has been reached the hysterisis time drops as there are no lockout timming circuits involved. So the implication is that you will still have to program in the reliabilty aspect.

However I do not have any real life experience of it.



 Posted: Saturday Sep 27th, 2008 01:53 pm
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andrew
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I built my own, specifically because I needed two outputs, one for switching indoor lighting and one for switching outdoor lighting. The unit uses only one photocell, but has two separately adjustable outputs. Maybe something worth thinking about if a new light sensor is designed.



 Posted: Sunday Sep 28th, 2008 02:35 pm
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garym999
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Actually a common problem. So a properly designed LSM that outputs an stable analogue value in to Comfort. Then you can use this to trigger different events based on differning light levels.



 Posted: Sunday Sep 28th, 2008 03:51 pm
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slychiu
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There are a number of wireless light and other sensors using Enocean technology which shall be a good option to use with Comfort when the UCM/Enocean is ready



 Posted: Thursday Oct 21st, 2010 06:38 am
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blowoutbedding
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The ambient light sensor on the newer Unibody MacBook Pro (all models: 13″, 15″, 17″) is available on macbooks. it located directly next to the iSight camera at the top of the display.



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