Viewing 8 posts - 1 through 8 (of 24 total)
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  • #7470
    Picmicro675Picmicro675
    Moderator

    Hello forum,
    I'm imagining a method to control the AC motor that keeps the rpm stable. For the number of components I think I put a PIC, you also win economically.
    The fact is that for an oversight of the purchase I only have MOC3061 in the drawers, who are with the ZCD. Then I would suppose to split the half-waves of a second proportionally. I was thinking of finding the space inside the drill to be able to mount an optical or Hall effect sensor. If the space is enough, maybe I could mount everything inside the shell of the drill, without taking out the speedometer signal.
    Col PIC, I would have thought of using a regular transformer in order to catch the half-waves after the diode bridge, but this does not allow miniaturization. The zero crossing signal should give me an interrupt to indicate the pause start period for attacking the TRIAC, but not with the MOC3061. It would also keep the count to arrive at a second so that timer 1 counts the impulses of the speedometer. Timer0 should count a pause period before triggering the TRIAC and a period to disconnect the TRIAC gate on.
    In the sense of partializing the number of half-waves, I am not yet clear which method might be suitable. In a way, a dozen values ​​could also be determined, which would be the percentage of a second, in fact they are 100 half-waves per second. Maybe we start from 10% and go up to 100%. In practice it can be said that they would be 2 whole waves for the minimum and a break of others 48, or interleaved 1 every 10. The calculation varies slightly going up in percentage, if we have 20%, then they would be 1 its 5, if it were the 30% we try to distribute it 3 its 10, and so on.
    Then the speed feedback should vary with an intensity proportional to the distance to be reached.

    Let me know your opinions. Maybe I'll have to go get the MOC3023 (who are more sensitive than the '21)…

    #7472
    Amilcare
    Keymaster

    I have in mind a sinusoidal regulator with alternating 230V input and output 0 – 225V with regulation trimmer and transistor instead of the triac. Give me a few days to be able to test my idea. It could also be a hole in the water but if I don't try I will never know.
    I don't know if your half-wave suppression system could be valid for an engine, I used a similar system for heating the welder but I never considered the feasible thing for an engine. Maybe I'm wrong I'm not too well versed in 230V electric motors

    #7475
    A_X_CA_X_C
    Keymaster


    I don't know if Hamilcar has to do in this period but I will pass you a pattern that in the past made for me

    #7477
    Picmicro675Picmicro675
    Moderator

    Beautiful scheme, after all I don't need to go to the moon, if it regulates fairly well I can also use the OP-AMPs.
    Well today I went to do some spesucccia and in the end I took the MOC3021, but it would be for the method for a double insulation circuit. Then input transformer and the Triac piloted by the MOC3021.
    I was looking for capacitors from 0,47 uF per lo snubber, but I only found it 0,56 uF. I don't have the correct idea how to fix the fact, I'm in approximation.

    I'll do some experiments, with this scheme, but I guess I don't have such big resistances, maybe I'll have to put the smaller ones in series.
    Thanks for the idea…

    #7479
    Amilcare
    Keymaster

    They are pretty big 0.56uF alternating for a snubber
    If you were to use them for a ballast power supply you could get us on 40mA
    A bit’ perhaps you have written badly and are 56nF, in that case you don't have to do anything the snubber is fine with that value too.

    #7481
    Amilcare
    Keymaster

    That scheme has the advantage of having a departure without excessive cues and rules from 100% a 30% without power loss, under al 30% the regulation shows power losses but it works.
    The pattern is not all mine is a reworking with European components of a Russian pattern used in their professional drills.
    Processing was necessary as not all components have a European equivalent. I chose it for its compactness and simplicity, if you require good powers remember to fin the triac because it warms up a little’

    #7483
    Picmicro675Picmicro675
    Moderator

    On capacitors that I found it says 564 630V 😛
    It is easy that the circuit of the scheme will be the optimal choice for keeping everything inside the drill. Or I should change the cable and use something that leads out 6 wires, so that I make the ring closed with the speedometer. If it were to shorten the time I could even take it one that comes from the east. But I would say that as a hobby I am interested in assembling it by myself.

    #7485
    Amilcare
    Keymaster

    564 It is like saying 56 followed by 4 zeros = 560.000pF = 560nF = 0.56uF far too short to short the triac
    The reactance added to the resistance is equivalent to 5.8k to shunt the triac when it does not conduct

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