ok guys this dose not have anything to do with robots
but a circuit im working on.
ok i have built an ac to dc converter/tripler (a basic rectifier)
it takes 1.5 to 2.5v ac (from a stepper motor used as a genarator) and puts out about 6 to 7 volts dc
but with little to no amprage/current i lose it though the circuit
so my ? is how can i boost or dubble amprage/current if at all posible
i have googled to no end but im not shore what it is im looking for
so there for a tool (google) is only good if you know how to use it.
any help is great
thanks
You can’t get something for nothing!
If you triple the voltage, you will similarly divide the current by three.
Alan KM6VV
thats what i thought 
so to get more out i would need more in
thanks
you are dealing with a couple of issues… first the stepper motor is not designed to be a generator, and second your rectifier circuit has poor efficiency.
If you were to put a load on the stepper output directly you would most likely observe the voltage falls off pretty quickly. stepper motors have lots of poles (200 is pretty typical) and each is relatively small cross sectional area.
your rectifier, assuming you used a full-wave bridge, if constructed with common silicon rectifier diodes like 1N4001 will drop 0.7V on each leg. so you loose 1.4V right off the top and it gets worse as the current goes up.
if you were to try a small brushless hobby motor (using a 3-phase rectifier) like used in r/c planes, helis, and cars you would get better results because it has a lot fewer poles and they are physically much larger. keep in mind you are still using a motor as a generator so it’s not going to be great but for the same size package as the stepper motor it will be better.
you should also try shottkey diodes, such as a 1N5819, in your rectifier as they will have less forward voltage drop and therefore you waste less energy in the diodes. a three-phase rectifier is similar to a full-wave bridge with (3) pairs of diodes rather than (2). look it up, it’s not that hard to find. 
Hold on here. So you have this working? It depends on what you mean by increase the amperage. If you use the circuit to charge a cap, you may be able to build up some energy that can be dumped in short order. But if you are looking for a continuous current then you need a larger motor, regardless of the type. Can you explain the goal a little better?
yes i do have this working in the fact that it takes my small ac stepper motor’s ac voltage and tripels the voltage and puts out dc
there is no real goal here just experaminting (learning)
but i was trying to run a smaller dc can motor with the stepper motor
yes i would be looking for constent current not a short burst
so it seems i would need a) a bigger stepper or b) try out the dc motor and circuit above
thanks you guys are so great
there is no better community than the one here