Driver Settings and Current consumption

Hey there,

I just upgraded to an M140 2W Laser for wood engraving.
For the dummyload test I used 6 diodes and a 1ohm resistor.

With a multimeter connected to the restistor I increased the current through the driver up to 1600mV = 1600mA.

The weird thing is that my powersupply only showes a current drain of about 0,8A.

Aso it seems to me that the laser-intensity does not equal 2W right now.

The question is:
Am I doing something wrong?
Is it just a missunderstanding that the powersupply and
diode current should be quite equal?

Could it be that I have destroyed the diode already?

Thanks for any help or comments

Thomas

What driver are you using?

marcuspeh said:

What driver are you using?

Click to expand...

I'm using one of these

Laser Driver


Wavelengths: 405nm – 660nm (adjustable output voltage)
Output Power: 200 - 2000mW (2.5A maximum)
Output current set using multi-turn pot on the circuit board
Input Voltage: 12V nominal, 8-14V AC or DC
Dimensions: 49mm x 29mm x 15.5mm; mounting holes are M3 16mm separation
Optional TTL modulation: 5V, 20kHz

You should be using three diodes and a 1ohm, not 6 diodes. This will more accurately replicate the voltage drop of a blue diode.

You are using a buck driver. It is a type of DCDC converter. It, like transformers, can lower the voltage to increase the current capability. Or in some designs can increase the voltage at the cost of reduced current capability.

In short, input current is expected to differ from output current.