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    closed loop DC motor speed control

    havent got around to trying it yet :rolleyes:.....
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    closed loop DC motor speed control

    I dont know of any way of extracting a reference sync...
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    closed loop DC motor speed control

    The generator motor outputs about 6V at the required speed....yes the top shaft is the main projector shaft
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    closed loop DC motor speed control

    With the gearing I have, about 3000 RPM at the motor gives about 1000 at the shaft......11V @1.2A
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    closed loop DC motor speed control

    piclt : for reference I checked the motor current with absolutely no load and nothing connected to it and guess what....at 12V it was 400mA :) Maybe the spec got confused in translation.....anyway as previously stated it is quite a powerful motor
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    closed loop DC motor speed control

    Problem is I don't think there's any way of getting to the sync pses from the camera (camcorder) - a Sony FDR-AX53
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    closed loop DC motor speed control

    Wow..... I had previously proved that recording the cine film worked with the original AC motor but over time there was a slight drift and therefore the black bars. I fitted the DC motor in order to be able to control it's speed a bit "easier" (????)
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    closed loop DC motor speed control

    well yes.... at 1fps it would take around 5 hours to copy a 20 minute film... As we are heading towards PICAXE would it not be easier to re-fit the slotted opto switch that I originally suggested and program the pic to count the number of pulses, compare that with the required number of pulses...
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    closed loop DC motor speed control

    Hmmmm....I am using that motor but it doesnt seem over stressed.....and after 20 minutes running is barely warm! The spec says it is a 12V 30W motor which would equate to 2.5A....there is also a 24V version which would still be 1.25A.....that 400mA looks wrong, it is quite a "beefy" and powerful...
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    closed loop DC motor speed control

    the motor pulls about 1.3A at the desired speed I am using STP55NF06L VMOS as they have always been my choice and seem to work well in just about anything, it does not even get warm so I know it is fully conducting
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    closed loop DC motor speed control

    apologies...I WILL be running it from an old laptop PSU - 15V@5A....at the moment I am running it from my bench PSU at about 12V, tweaked to get 1000RPM at the shaft in your previous post you asked "Where does Picaxe fit in.? " :) I do not know how to tweak a switch mode PSU....and it is all...
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    closed loop DC motor speed control

    I ran it from a stabilised PSU (an old laptop one)....."the picaxe fits in" as the motor speed will vary very slightly due to load, friction, temperature and who knows what else is still needs to be regulated
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    closed loop DC motor speed control

    I have already replaced the bulb with a DC driven LED and there are no issues with it :) Main problem now is to get the motor speed precise...I have engineered the attached to drive a small DC motor which generates 6V at the required speed I am still favouring a PICAXE PWM controlled system...
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    closed loop DC motor speed control

    Again thanks... I don't THINK the frequency matters here...it is the mark-space ratio that is important as that is what is controlling the motor speed
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    closed loop DC motor speed control

    hmmm...would something as simple a a CMOS based 555 variable mark-space generator circuit do the trick... ....adding an averaged voltage derived from a slotted opto switch to pin 5 of the 555 to give feedback/control feasible ???
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    closed loop DC motor speed control

    ....but maybe not within mine :(
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    closed loop DC motor speed control

    Thanks for your prompt response I can sort / make any electronics hardware as required...there will (can) be no synchronisation between the camera and projector ....which is why I need a precise and accurate speed controller. I have set it (with voltage only) to run at about the right speed...
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    closed loop DC motor speed control

    I am trying to copy old 8mm cine film to digital using a projector I have been through hoops of trial and error and have settled on videoing the actual film itself using a close focus lens looking directly at the film gate (i.e. emulsion side) with the projection lens removed as it gives...
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    Android app

    Waaaaaaay above my head :(
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    Android app

    I'm sure it's been asked many times but is there or will there ever be an app for Android to connect to PIC......even if we can't program it, something to monitor any sertxd commands would be helpful when debugging
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