new P7 driver 3amps?

[CM]

Their 90%-95% efficiency claim is suspicious. I wouldn't believe it until someone measures it and states the condition under which it was tested.

 

[CM]

double tap

 

[SUBjohan]

Their 90%-95% efficiency claim is suspicious. Sounds too good to be true.

Its is to good to be true. :mecry:
But 83,5% is good enough for me

I have measured the thing and I have to say I like it.
Unlike I have read somewhere else these drivers do have a memory function.
They will start working from 4,7Volts, they will stop working at 4,0Volts than the driver goes into a verry verry low mode (3mA to the led).
I did'nt see any flickering

Well here are the measurements in a excel file.

All measurements where made with calibrated meters.

Greetz Johan

 

[StefanFS]

Its is to good to be true. :mecry:
But 83,5% is good enough for me

I have measured the thing and I have to say I like it.
Unlike I have read somewhere else these drivers do have a memory function.
They will start working from 4,7Volts, they will stop working at 4,0Volts than the driver goes into a verry verry low mode (3mA to the led).
I did'nt see any flickering

Well here are the measurements in a excel file.

All measurements where made with calibrated meters.

Greetz Johan

How does the memory function work? In the drivers I got it just progresses to the next level every time you turn it on. Turn it off on low and it's on high the next time you turn it on.

Your numbers seem to be good as I get ~2.7 A in the 6-7.5V range on high. ~80% is not bad. You did a lot of work to get that table on input/output, nice.

Stefan
-----------------------------
Edit! 2008-08-08.

One driver was obviously mangled in transit and malfunctioned. I rewired the other drivers and after that they seem to have a memory function when off for 5 sec. or longer. On 6 AA NiMH it will drive an SSC P7 to spec., more or less.

 

[SUBjohan]

How does the memory function work? In the drivers I got it just progresses to the next level every time you turn it on. Turn it off on low and it's on high the next time you turn it on.

Stefan

Just turn it off in a mode, wait a bit and turn it on again and then its in the same mode as before.

Perhaps there is a difference in drivers, because my driver also came with a sort of rubber protection thingy for the coil wich is not seen on the KD pictures.

Greetz Johan

 

[jirik_cz]

Good work SUBjohan. If you don't mind I've made graphs from your data.

 

[SUBjohan]

Good work SUBjohan. If you don't mind I've made graphs from your data.

Nice :thumbsup:

 

[StefanFS]

Just turn it off in a mode, wait a bit and turn it on again and then its in the same mode as before.

Perhaps there is a difference in drivers, because my driver also came with a sort of rubber protection thingy for the coil wich is not seen on the KD pictures.

Greetz Johan

Incredible! They have different versions in the first batch. I have no form of memory in the ones I received. Turn it off on high, wait, it turns on in the low level next time it's turned on! And they had the rubber protection sponge.

 

[SUBjohan]

Incredible! They have different versions in the first batch. I have no form of memory in the ones I received. Turn it off on high, wait, it turns on in the low level next time it's turned on! And they had the rubber protection sponge.

This is really incredible!!! but not in a good way
Perhaps Kai could give a anwser to this problem ?

Greetz Johan

 

[Bimmerboy]

Perhaps Kai could give a anwser to this problem ?

In my experience, when buying cheap, "made in China" stuff, two units of the very same item produced in China will, many times, have similar, but somewhat different components. That the supposedly same driver, received by two different people, works differently should not come as a total surprise.

My suspicion is that you will not get a clear, understandable answer on this one, if any.

 

[Meterman]

Well here are the measurements in a excel file.

All measurements where made with calibrated meters.

Hi SUBjohan,

Your excel file is a very good job!

I like precise measurements, in German I say "WER MIT MIST MISST, MISST MIST." It's a pity that in translation the play on words gets lost.

How do you measure currents? My new AC/DC current clamp (Chauvin Arnoux K1) has a span from 1mA to 4500mA and very small jaws.

Wulf

 

[StefanFS]

In my experience, when buying cheap, "made in China" stuff, two units of the very same item produced in China will, many times, have similar, but somewhat different components. That the supposedly same driver, received by two different people, works differently should not come as a total surprise.

My suspicion is that you will not get a clear, understandable answer on this one, if any.

That can be true sometimes. I have been lucky with the stuff from China I have been using so far, but I try to select what seem to be good quality. Buying cheap has different meaning in different parts of the world, I know that it can sometimes mean 'trash' or low quality in the US. Here cheap (billigt) can also mean that you made a bargain. I think there might be different UI versions coexisting and that the seller missed this detail, and the versions are mixed. The driver works well and seem to be very well built, it's the software that differs in the sense that my units have no memory function.
Stefan

 

[SUBjohan]

Hi SUBjohan,

Your excel file is a very good job!

I like precise measurements, in German I say "WER MIT MIST MISST, MISST MIST." It's a pity that in translation the play on words gets lost.

How do you measure currents? My new AC/DC current clamp (Chauvin Arnoux K1) has a span from 1mA to 4500mA and very small jaws.

Wulf

Yes, in The Netherlands we have the same kind of saying "Meten is weten, maar dan moet je wel weten wat je meet".

I used 4 GossenMetrawatt Metrahit 29S multimeters so could measure everything in the same time.

Greetz Johan

 

[Meterman]

I used 4 GossenMetrawatt Metrahit 29S multimeters so could measure everything in the same time.

That's really a bunch to have a lot of precision at the same time!

Of this series I employ a Metrahit 27M, specially designed for measuring mainly mΩ and μΩ.

But I'm afraid we go OT.

Wulf

 

[manne]

Thanks for the usefull measurements SUBjohan, the poor efficiency on med and low looks like they use a improper way to dim, like simply a PIC (12f629 or something similar) that PWM the input voltage per MOSFET oder regulator's enable pin, can you confirm this? So maybe it should be possible to modify it to one mode?

 

[TorchBoy]

... the poor efficiency on med and low looks like they use a improper way to dim, ...

Add to that, I'm disappointed the medium isn't more logarithmically placed between the other two, but that wouldn't suit everyone either. It would be nice to be able to set them wherever.

 

[Galiphrey]

That drop of efficiency for medium makes it look like the driver is loosing the same amount of power whether in medium or high mode (instead of loss being as a proportion of the mode).

 

[spencer]

Mine has a memory function. Just got this driver and so far I like it.

Excellent work on the measurements SUBjohan

 

[DocD]

So i've been reading the replys and it seem to be a positive towards these driver's but they are not very efficent on med and low ? in the real word does this shorten run time by converting power into heat ? how does it hold up against other drivers ? cheers DocD

 

[StefanFS]

So i've been reading the replys and it seem to be a positive towards these driver's but they are not very efficent on med and low ? in the real word does this shorten run time by converting power into heat ? how does it hold up against other drivers ? cheers DocD

They seem to work well enough. About efficiency on low & med real world runtimes needs to be performed in addition to the calculations made.

Stefan