I have a bridgelux BXRA-50C2600-B-00 with the specs being 3040 lm @ 700mA and 37.4V

I'm driving it with a FlexBlock A011 how I have it connected is Vin to my supply and LED +/- to the LED

Now in the datasheet it says in this mode it's in Buck-Boost mode in which it allows the input voltage to be below, the same, orabove the output voltage.

I only ask because if it's really at 3000 lm it seems well not as bright as I thought.. I've messed around with a 700 lm LED before

 

/me still waiting for the question.

 

I'm asking why run it as boost only? in the datasheet it says the default mode is buck-boost but in the default mode is it enough to drive a 37V LED?

page 4

http://www.luxdrive.com/content/FlexBlock_A011_V1.pdf

 

I'm asking why run it as boost only? in the datasheet it says the default mode is buck-boost but in the default mode is it enough to drive a 37V LED?

page 4

http://www.luxdrive.com/content/FlexBlock_A011_V1.pdf

Ok. If I understand the datasheet correctly, you are using Default (Buck-Boost Mode), then: Vout=48-Vin
Vout is forward voltage of your led, 37 volts
Vin is external voltage to the led driver
So.
37=48-Vin
Vin=48-37
Vin=11 volts

If I understand datasheet correctly, in order for you to power the led you need to input 11 volts to the FlexBlock when FlexBlock is in Default mode of operation, that will result in the output that is 37 volts that you need to power the led.

 

Ok. If I understand the datasheet correctly, you are using Default (Buck-Boost Mode), then: Vout=48-Vin
Vout is forward voltage of your led, 37 volts
Vin is external voltage to the led driver
So.
37=48-Vin
Vin=48-37
Vin=11 volts

If I understand datasheet correctly, in order for you to power the led you need to input 11 volts to the FlexBlock when FlexBlock is in Default mode of operation, that will result in the output that is 37 volts that you need to power the led.

To measure the current I measure between supply ground and LED + right?

 

To measure the current I measure between supply ground and LED + right?

The current through the LED?

 

The current through the LED?

yes that is correct

 

yes that is correct

In order to measure current, you need to place current meter (or multimeter set to measure current) in series with the device whose current you want to measure. In this case current meter will be in series with led.

So. On FlexBlock run wire from LED+ to positive terminal of the current meter, then run wire from negative terminal of the current meter to the positive terminal of the bridgelux, then run wire from negative terminal of bridgelux to the LED- on the FlexBLock.