I am building a laser plotter with a dismantled etch a sketch. A stepper motors are attached to each knob and controlled via two ULN2003s by my parallel port. The laser is attached to the stylus of the etch a sketch and its driving circuit, which is in turn connected to a 7.2V 1400mAh rechargeable Ni-Cd battery.
I have a big problem though! The parallel port must also be able to switch on and off the current from the battery to the laser driving circuit, which is a maximum of 400mA. I just recieved four 4N35 Optocouplers that I ordered:
http://www.datasheetcatalog.org/datasheet2/1/03tgz200g5x4946jka7isojyj5wy.pdf
And I realize that their absolute maximum collector current is 100mA. Im not entirely sure how I would use these at the moment, but I think a maximum collector current of 100mA will not do, as the 400mA should be flowing from collector to emitter.
Your advice is appreciated. What is the best way to switch on and off 400mA of current from one pin of my parallel port? Should I just go looking for another optocoupler with higher current rating? Am I on the right track generally?
I have a big problem though! The parallel port must also be able to switch on and off the current from the battery to the laser driving circuit, which is a maximum of 400mA. I just recieved four 4N35 Optocouplers that I ordered:
http://www.datasheetcatalog.org/datasheet2/1/03tgz200g5x4946jka7isojyj5wy.pdf
And I realize that their absolute maximum collector current is 100mA. Im not entirely sure how I would use these at the moment, but I think a maximum collector current of 100mA will not do, as the 400mA should be flowing from collector to emitter.
Your advice is appreciated. What is the best way to switch on and off 400mA of current from one pin of my parallel port? Should I just go looking for another optocoupler with higher current rating? Am I on the right track generally?