manually setting badboy output current

[tylerdurden]

When manually setting the babboy's output level, if I am only using one resistor, does it matter if it's on the R2 or R2A pad?

What about for downboys, wiz2 etc?

Thanks.

 

[tylerdurden]

BTW, is there any way to test that the resistors are seated correctly other than a full-on test with emitter and full power? Can I just probe somewhere with a multimeter and read the resistance? I can't get my probes on the pads without touching the resistor itself, which would defeat the purpose of testing the solder joints.

 

[dat2zip]

On all the current revision boards it will not matter which location the single resistor is located. Either one will do.

Testing if the resistor is correct.

On the Badboy. Applying 1.5V should have voltage on the output since the IC is below switching levels. A Luxeon attached should show 3V or so if it's soldered. Zero volts there is no sense resistor.


Downboy. Similar thing. Applying a voltage less than Vf should put it in DD and the Luxeon should get the full Vin applied across it. 3V is a good voltage to test 1W/3W white Luxeons. ~2-2.5V for Amber/Red ones. It's safe to slowely ramp up Vin and see if you are in DD. The LED should light dimly at around 2.5-3V depending on the Vf bin code of the LED you have hooked up.

I personally ramp up Vin using a power supply for both of these configuration and note when the LED just barely light up. This is very consistent for the same converter board. Noting when a good one fires up and then using that as a go no go test is what I do.


Revision 4 should not fry if no load. Another test method is to touch Vin to 3V and measure Vout with a Voltmeter. It should boost and regulate to 20V or so.

I would recommend to just tap it on the battery and then remove it. The output should remain at 20V for some time.

A 10X loupe is a good inspection tool. With a 10X loupe you can see the solder joints very well in good lighting.

No clean flux pens help immensly in soldering the resistors on. I dab the solder pads with no clean flux, press the resistor down and touch one side and then the other with the soldering tip.

Wayne

 

[tylerdurden]

Thanks for the tips. I definitely need the loupe, the magnifying glass desk lamp I have isn't enough.