New configuration option needed for specific but popular setups eg. LED strips

[nepozs]

New configuration option needed for specific but popular setups eg. LED strips

[bramstroker]

Would be easy to implement a "multiply factor", but how does a user determine the correct multiply factor? And will this be consistent over the whole brightness / color temp spectrum. Not sure about these things.

[nepozs]

how does a user determine the correct multiply factor?

It is very simple - LUT file must contain power value for 1m of strip or 1 piece of lamp - calculated after measure.

Some words about measuring:
eg. if LUT file is created using 5m of strip then every power value in ready made LUT file must be calculated by division by 5
if it was measured for 2 lamps connected then values in final LUT file should be divided by 2

Of course power draw used by driver will be also divided - so I've suggested measuring just after opening a box - it will minimize differences in real use - I think when someone buys 5m starter kit, he won't use only 0,5m of strip, but rather 4,5m or so.

And about use multiplier - if someone uses 4.5m of strip then he stets multiplier to 4.5 if 7.5m then 7.5

Some words about our measured values - they are not absolute exact, I can say that no one has laboratory conditions at home, so the values contains fluctuations due to voltage changes (power depends on voltage), due to parameter fluctuations in devices like bulbs and in our measurement devices and due to variable power factor, so it is best we can do.

It is voltage in my home (average graph) - it is only 1,6% fluctuation between real value and mean 240V~, but there are places with lower mean voltage (eg. 230V~).

[bramstroker]

I will give this another thought.
Not sure if we should divide values to have the LUT files converted to 1 meter (for hue ledstrip for example), or we use the default length as base. For the Hue lightstrip the default length (as you buy it in the store) is 2 meters, so imo the LUT file should be for the stock model (which is 2 meters). When the user has extended the strip he can apply the multiply factor accordingly. But he shouldn't need to do anything when using the default model, because this will be error prone.
But also see this post, he said power should be the same even when the led strip is extended.

I know we don't have laboratorium conditions at home, when the measured values are close enough users have a good indication about there power consumption which is what this component is all about. It does not has to be scientifically perfect.

[nepozs]

For the Hue lightstrip the default length (as you buy it in the store) is 2 meters, so imo the LUT file should be for the stock model (which is 2 meters). When the user has extended the strip he can apply the multiply factor accordingly. But he shouldn't need to do anything when using the default model, because this will be error prone.

Maybe it is really better solution, but linked above Ikea lamps are sold separately (and only requirement is not to exceed the driver specification), so how they should be measured?

I think about conversion to unitary value, because it does not matter if starter-kit contains 2m of strip or 5m of strip or 2 lamps or 3 lamps, but maybe better is to measure standard contents of the package as single unit.
It is just to be documented properly, but some kind of multiplier/factor is a must (because I do not know any person who use standard length of strip :P).

Something about my "laboratory"

[bramstroker]

Haha nice laboratory ;-).

I have also found this article https://atomstar.tweakblogs.net/blog/17888/measuring-calibrated-hue-energy-usage-via-bridge.
This guy had measured 2m and extended 4m strip, but the 4 meter strip only uses 40% more power (not 100% more). So this feature will be almost undoable to implement :-(

[Leatherface75]

Haha nice laboratory ;-).

I have also found this article https://atomstar.tweakblogs.net/blog/17888/measuring-calibrated-hue-energy-usage-via-bridge.
This guy had measured 2m and extended 4m strip, but the 4 meter strip only uses 40% more power (not 100% more). So this feature will be almost undoable to implement :-(

Could be a standardvalue for 2 meters and then a configure option for additional meters.
The reason it doesn't take 100% more power is that with addional meters it will affect the brightness because total lumen is still the same with addional meters. 40% additional more power sounds infact much for me.
Would be nice with results from other configurations but maybe it's 20% more power for each meter?

[OzGav]

Another case when the multiplier would be useful is in my house I have a room with 6 RS125 downlights. I don't need to have a sensor for each of them so currently I have a powercalc sensor for one of them and then I have a template sensor which multiplies that one by six for the total room power when that one is on (since they all get turned on and off as a group). It would be great if I didn't need the template sensor but I could just use the multiplier. This isn't an isolated case for me, My dining room has two identcal bulbs and I have corridors with 3 and 4 identical bulbs....

[bramstroker]

Haha nice laboratory ;-).
I have also found this article https://atomstar.tweakblogs.net/blog/17888/measuring-calibrated-hue-energy-usage-via-bridge.
This guy had measured 2m and extended 4m strip, but the 4 meter strip only uses 40% more power (not 100% more). So this feature will be almost undoable to implement :-(

Could be a standardvalue for 2 meters and then a configure option for additional meters.
The reason it doesn't take 100% more power is that with addional meters it will affect the brightness because total lumen is still the same with addional meters. 40% additional more power sounds infact much for me.
Would be nice with results from other configurations but maybe it's 20% more power for each meter?

I have installed some led strips myself (just the standard ones) with a custom led driver and a gledopto controller (so I can control them via zigbee). Each led just draws a certain amount of power on full brightness so I just make sure the LED driver has enough amps to control the full length on full brightness. So in this circumstance doubling the amount of meters will also double the amount of watts.
The Hue driver (adapter) is rated for a max amount of amps, so when you make the strip to long it each individual light will not have enougt power, thus resulting in a lower brightness output.
The problem is we don't know which kind of configurations the user has, so it will be a lot of guesses.

[bramstroker]

Another case when the multiplier would be useful is in my house I have a room with 6 RS125 downlights. I don't need to have a sensor for each of them so currently I have a powercalc sensor for one of them and then I have a template sensor which multiplies that one by six for the total room power when that one is on (since they all get turned on and off as a group). It would be great if I didn't need the template sensor but I could just use the multiplier. This isn't an isolated case for me, My dining room has two identcal bulbs and I have corridors with 3 and 4 identical bulbs....

Yes this is a perfect usecase for this feature request. I also have a room with 6 GU spots and now have 6 power sensors (and a template sensor to sum them up), but it would be much nicer to have a single power sensor as I also control these as a group.

[bramstroker]

See #103

[bramstroker]

I have added some information to the readme about the new configuration option.
See:
https://github.com/bramstroker/homeassistant-powercalc/tree/feature/multiply_factor#sensor-configuration
https://github.com/bramstroker/homeassistant-powercalc/tree/feature/multiply_factor#multiply-factor

Let me know if you have any additions.

[Leatherface75]

Nice option that should fix the above example with a factor of 1.4 for example.

[bramstroker]

Nice option that should fix the above example with a factor of 1.4 for example.

Yes exactly, if you want 40% more power you use 1.4.

[nepozs]

I have also found this article https://atomstar.tweakblogs.net/blog/17888/measuring-calibrated-hue-energy-usage-via-bridge.

In this case results of the measurement of the strips look unbelievable, efficiency of driver depends on load, but such a big difference is not possible (it is likely only in case of overload when driver is full saturated) as it @Leatherface75 said before.

The problem is we don't know which kind of configurations the user has, so it will be a lot of guesses.

It is not our problem - when configuration is build within specs (driver isn't overloaded) - additional (or subtracted) load could be estimated as linear change, so multiplication factor is OK.

But standby_power is the same in all cases (added or subtracted driver load) - it concerns strips driver and integrated lamps driver (as Ikea models mentioned in first post), but…

Different case is a group of any independent bulbs or lamps (when each uses own driver) - in such case standby_power should be also multiplied.

[bramstroker]

Feature has been merged to master. Closing this issue