LED Driver alternative

[Avo Mk8]

Good spot, I think you're right and I've edited the above post. Can we discover the relationship of resistor to current for Gen. 1 drivers?

I found this (description! of link in my post #7) see below:
My attempts at unravelling this from the 274uA current, (presumably from 12V) - and I really haven't understood this - suggested someting like 7V across Rset, which would be driving the lamp a bit over 400mA.



Post crossed with yours Lucien!
I thought I had worked out the source impedance of the 274uA and I had a potential divider of that and Rset which led to a voltage across Rset that I mention above.
Clearly something wrong with that!! Yes - it's a constant current source DUH! Prefer your version.

 

[Lucien Nunes]

Oops, post crossed with yours.

It seems the Gen1 interface sets the fraction of the rated output current, not the absolute current, in the relationship: Iout = Inom ((Vset-1)/9). Vset can be derived from an active voltage source in a remote control, optionally referenced to the driver's +12V aux supply, or can be created passively by a resistor driven by a constant 274μA bias current that flows out of the control terminal. Thus for a 16kΩ resistor:
Vset = 274μ * 16k = 4.4V
Iout = 700 * ((Vset-1)/9) = 263mA

That's an even lower fraction of the panel's rating and is starting to sound unlikely.

To set a Gen1 driver of 700mA rating to 605mA with a resistor, one would need:
Vset = 605/700 * 9 +1 = 8.8V
Rset = Vset/274μ = 32kΩ or 33kΩ as the nearest preferred value.

Perhaps we are not seeing the colours on the resistor correctly, but I can't resolve them to anything like 33kΩ

 

[KAZ786]

hi,

coming back to this after a couple of years;
resistor colors are as follows Orange,blue, black,red, brown

Tridonic Linear Outdoor LCO 75W LED Driver fixC L SNC2 (500mA)

A fixed output built-in LED driver providing a 500mA output current at a 92% efficiency. This driver was designed for luminaires of protection class I.

bltdirect.com

Is this still an option

 

[Avo Mk8]

resistor colors are as follows Orange,blue, black,red, brown

The resistor value appears to be 36K 5%, a little off Lucien's 33K sum above.
If it is 36K, I calculate it's programming the power supply to produce 684mA, somewhat over the target 605mA.
Maybe that's why lamps were suffering?

Is this still an option

Yes I think so.

The Tridonic driver will give 500mA so the lamps will produce a little less light output, but they ought to last longer!

 

[plugsandsparks]

Sadly these drivers are now discontinued, been looking for a couple of 100W versions and had to resort to Ebay.
The replacements are current set by NFC programming which you can get done but there is a charge. No sure of the available steps and you may get closer to 600mA rather than settling for 500mA
If you go to the Tridonic website its straight forward to choose a suitable driver