DVD-RW (Liteon) teardown stuff details (motors,laser diodes IR & red visual,etc) - Page 1
Forum section: electronics / projects

author: eneuro
author_rank: Super Contributor
timestamp: July 08, 2015, 12:20:37 pm
content: Hello,I've made teardown of DVD-RW (Liteon) to reuse a few components in another project and trying to findout more details about stuff like thisIts laser optics probably will be very usefull in custom encoder since it has decent (huge) magnification when combined with second lensOf course we can find in DVD-RW red laser diodeIR laser diode (invisible be very carefull with those DVD-RW laser diodes) is available too-maybe it could be usefull as light source in this encoder, but of course a lot of attention should be made and ensure to make its output very low power...Not sure which laser diode is used as lightscriber to groove DVD/CD marks?Update: I've found exellent teardown of those laser diodes therePowerful laser diodes from DVD-RW driveQuoteAnyway, we have quite nice 3 phase BLDC motor there with analog Hall sensorsClassic DC motor used to open DVD-RW front doorsSo. we have 3 low power electric motors and optics for encoder module-looks like it can be reused in... small pick & place prototype I'm working on, since no huge motors needed to drive its axis, but a few more encoders to easy estimate overall position, so it doesn't matter for the moment what kinds of motors will be used, since control logic will be similar-bigger motors will need more power, but mechanical concept remains the same-no huge precision needed to pick & place SMD components, while final component placement will be corrected using visual camera (usb microscope) top viewTrying to findout more details about this motor (DC I guess) which moves laser diodes and optics module, since I'd like use it with custom driver to hold USB microscope and move in Z vertical axis:More detailed view below-it has E232171 markings and 10 Ohm resistance between right two pins, but it looks like there is no pure resistance between another two left pinsWhat can be purpose of those two left pins in this motor?

author: amyk
author_rank: Super Contributor
timestamp: July 08, 2015, 01:09:16 pm
content: That head motor is a bipolar stepper, similar to the type found on floppy drives.

author: eneuro
author_rank: Super Contributor
timestamp: July 08, 2015, 01:21:29 pm
content: Thanks, it is nice to know that this laser diodes & optics holder motor it is some kind of stepper -I should be easier to control its position, since it is difficult to add there decent resolution optical encoderBut there is no pure resistance between those two left motor connectors and those another two (10 Ohm)?Update: OK, maybe those left two pins were well insulated or battery going dead in multimeter and missed that those left two pins should be another pair of windings of the bipolar stepper motorI've spare ULN2803, so will try build something to drive this bipolar motor tooDriving a Bipolar Stepper Motor with Arduino and ULN2803AGAnother interesting usage of those DVD bipolar steppers thereDIY BioPrinterQuoteLooks like they have similar parameters? 10 Ohm phase coil resistance, 5V, 20 steps per rotationSample datasheet:http://robocup.idi.ntnu.no/wiki/images/c/c6/PL15S020.pdfHolly crap! They are used in small CNC plotter and it worksMicro Mini CNC Plotter - Part 1 - XY Using DVD SteppersMicro Mini CNC Plotter - Part 2 - Testing Hardware and SoftwareI do not know why those Youtube links doesn't work under my Firefox?Wow, really nice tiny bipolar steppers from crappy DVDs, etc