Setting the milliamps on a driver question

[Momo66342]

I understand the whole thing about having a test load and a multimeter.I just dont get one thing.How do I connect the driver to the test load? Also, how to I connect the multimeter?

 

[elitesniper]

connect probs one both sides on the 1 ohm resistor?

 

[Bionic-Badger]

Solder (or just connect) the test load on as if it were a diode. In fact, most test loads have diodes on them, so use the same polarity (+ or -) as you would your laser diode. A laser diode is just another "load" -- just it's hard to measure the current on it. So we use a test load, which is "calibrated" with a known resistance that you can measure for the current.

 

[chipdouglas]

hey momo, i have referred you to www.rog8811.com in the past. it is a great website. give it a try, it won't bite! not only is it user friendly, but there are lots of pictures.

 

[Gryphon]

Connect the positive of the test load to the positive output lead of the driver and the same for the negative, just like hooking up a laser diode. Then place one lead from your multimeter on one lead of the 1ohm resistor and the other multimeter lead to the other lead of the resistor so that you are measuring across it. Set your multimeter to millivolts and power up your circuit. Calculating 1mV = 1mA, adjust your driver so that your millivolt reading is that of what you want in mA.

Ex: If you want 110mA for a 803T, then adjust your circuit till you read 110mV across the 1ohm resistor.