6 Replies Latest reply on Jan 13, 2021 3:49 PM by powerking

    DC Generator

    powerking

      Hi, I would like everyone's option, on making a generator from a PMDC motor

      The primary and only task would be to charge a motorcycle size 12v battery. If I used a PMDC motor would I be able to fit a rectifier / regulator to convert the charge to dc and stop the battery overcharging, would this work?

      Or is it more complex than this, (and no I can't use a alternator as it will not fit).

      Cheers Wayne

        • Re: DC Generator
          dougw

          The short answer is a DC motor can be used as a generator. You will need to figure out what happens at all speeds.

          It might be useful to look at small wind turbine generators.

          Alternators are also available in a lot of sizes from micro alternators on up.

          How much space do you have?

          How big is your engine?

          How much current needs to be generated?

          How fast is the generator rotating? How is it connected to the engine?

          2 of 2 people found this helpful
          • Re: DC Generator
            jw0752

            Hi Wayne,

            The only need for a rectifier would be to block the battery power from causing the motor being used as a generator to draw current and run. Once you have the DCPM motor spinning fast enough to generate a voltage that is in excess of the battery voltage and junction drop of the diode a charging current will flow into the battery. As Doug points out you have left a lot of information out of your question and so our response to your question is qualified and limited.

             

            John

            3 of 3 people found this helpful
            • Re: DC Generator
              powerking

              Thanks for the replies, yes sorry I failed to explain clearly what I'm trying to achieve. I am also a novice in this field(so please be patience with me)

              My plan is to do a long trip on a 1920's motorcycle, and I would like to have reliable lights should for some unlikely situation ever need them. Also I would like to be able to recharge my phone by installing a power outlet on the bike.

              The motorcycle does not require the battery to run as it is magneto ignition, the battery would be only for lights and the power outlet

              the original 6v generator(which I do not have) is 84mm diameter and about180mm long. I would like what ever I use to look similar, but be a 12v system

              I not sure  what current I need to generate or size of motor,

              As you could imagine motor speed would vary and it would be driven off the motorcycle engine(1000cc) by belt

              Please let me know if you require any further info or is there a better way, or is it just a bad idea

              Cheers Wayne and thanks for your help

              2 of 2 people found this helpful
                • Re: DC Generator
                  jw0752

                  Hi Wayne,

                   

                  With this much potential power it would be advisable to have a regulator circuit to control the voltage that is applied to the battery. You may be able to find something that is designed for use on a commercial motorcycle electrical system.

                   

                  John

                  1 of 1 people found this helpful
                • Re: DC Generator
                  powerking

                  Thanks everyone for your help much appreciated