Hello all, I am thinking about using my lego motors with my arudino to use my vast collection of legos as a base for a rover robot i want to make.
I know i will need to use a motor controller chip or 2 to make it work thats no problem. The only thing im worried about is the fact that lego motors are very good a generating current and voltage if they are turned passively. I dont want to pass this voltage back into my system as it may damage the hardware,(im aware that i can use diodes to prevent this) however beyond this i think it would be interesting to attempt to turn that generated power into something i could recharge a LiPo battery with. This power harvesting would allow me to recycle power and keep my robot going longer. I am preaty good with hardware but i dont know of any ICs that support what i am looking to do.
If anyone knows of an IC that is designed to use power generated by a motor to recharge batteries then i would be open to any suggestions.
This is the same technique used in many hybrid cars, they use the breaking force of the electric motor to recharge batteries, train engines have used the technology for over a decade.
The only thing im worried about is the fact that lego motors are very good a generating current and voltage if they are turned passively.
That applies to all motors.
Normally this reverse voltage is shunted by a diode placed across the motor, but if you want to make use of this power then you can use diodes to direct it to the right place. However it is not as easy as it sounds because the voltage you get is peaky and generally not sustained.
Mike, I agree i was thinking of using diodes and then reverse direction diodes to send the power where i want it. The problem i am trying to overcome is how to store the power to something sustainable, maybe capacitors to build up something reasonable then dumping it into a charge system. I know it can be done, because it is done on large scale, my goal is to bring it down to a mA 5-12V level.
There may not be a specific IC that does this for me, and i know i can just waste the generate power into diodes, but it would be very innovative to be ables to harvest this power into a charge circuit.
The power you are talking about is going to be miniscule because of the size of the vehicle.
Fun idea, and I certainly explore many "pointless" things myself, but just keep in mind the problems of scale that you are going to encounter with this one.
If you were to build a bigger, and more importantly HEAVIER, vehicle, then you would have useful amounts of energy to withdraw as the vehicle is slowed.... but now you would be needing bigger motors and batteries to get it moving in the first place, and before long, you would also have something with enough energy in it to do damage if it "moved" someplace it shouldn't.....