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Open Source Micro Cassette Player
It wont look like the elbow elbow cassette player (different)
It wont look like the elbow elbow cassette player (different)
got the motor in the mail !
Hey everyone, I took a different approach to the cassette tape speed and I found an alternative motor for driving cassette tape. I did simulations to play the cassette tape and the rpm varies between 20-50 rpm. The motor is small which is good becauseit keeps the small form factor.
Small change on Distributor to Wuhan P&S
Ok i'm just ordering parts for measuring RPM from EMF. Based off the overall project I think only an arduino pro mini or teensy might be used. Thats good because the cost to build this thing will dramatically decrease.
The tape has to move at a constant 4.76cm/s rate. Based off the protoype design it didn't include the tachometer to measure the linear speed.
Im going to list 3 ways it may play correctly
Thanks to @Morning.Star for recommending a pre-amp for the Casette Tape Head. A Youtube video a google search later
http://piperidis.smartdev.gr/MyWebPage/Contructions/Amplifiers/tapeplayer/tapeplayerEN.htm
I ran out of 0805 cap SMDs just looking around for some assortment packs on ebay.
So far I was looking for a Square Card reader in my room, since they use tape heads. I found a 1st gen Square card reader and a 5th gen square card reader (which broke into tiny pieces when i tried taking it apart ). Based off Google search this 1st gen tape head reads mono audio. The next part is to design and assemble an amplifier to play audio off the cassette.
@Morning.Star Microchip TC652 uses FanSense(tm) to sense commutation of a DC brushless fan. They basically AC couple the current signal from a sensing resistor.
The speed is (was) normally stabilized without a tachometer, except in high class tape decks. Often analog motor control chips were used which evaluate back EMF of the motor and/or implement some kind of "negative resistance" to compensate for the rotor resistance. Without this resistance the moor speed would be perfectly proportional to the applied voltage, independent of mechanical load.
Sometimes such a control circuit was included into the motor casing.
Another possibility would be a brushless motor, where you get inherently a frequency proportional to it's speed. This can also done sensorless by evaluating back EMF of the winding which is not driven at the moment.
Thanks for the insite I will have to do research into back EMF, and the different possibilities including some that you suggested/.
https://www.precisionmicrodrives.com/application-notes/ab-021-measuring-rpm-from-back-emf
We meet again lol
hackaday.io/project/20876-origaime-cardware-bis/log/59055-skunkworks
right at the bottom...
Except my motor has a commutator. I was thinking of sampling the feed and counting the EMF spikes for metrics as a free replacement for encoder wheels etc, but I'd never heard of it being done. Damn, but at least I know it works. :-)
Ricardo Ferro
barb
Adam Smallcomb
FourthLevelMfg
Very cool nascent project. Looking forward to seeing how things progress!