DC Motor/Alternators

Have you done any research on your own? If yes, tell us what you have already done. It sounds like you are just starting?

Have you looked at any of these?

1. Alternator - Wikipedia, the free encyclopedia This output is rectified by a rotating rectifier assembly, mounted on the rotor, and the resultant DC supplies the rotating field of the main alternator and ...
   en.wikipedia.org/wiki/Alternator
2. DC Power Engineering - Welcome - 7:26amDC Power Engineering Inc. is a manufacturer of superior quality high-output alternators. Our mission is to fulfill our customers needs by offering the ...
   www.dcpowerinc.com/

never tried it

but if you take the output form an alternator before its rectified that would give you the ac portion and dc from the rectifiers as normal.

downside of course is any ac taken will reduce avalable dc.

but its just a thought

Certainly one can generate multiple stator voltages with one rotor magnetic field spinning. But I know of nobody that does this. A possible reason for this is that the multiple voltages will be correlated to each other. So any required voltage regulations of the separate voltage outputs must be accomplished separately from the alternator rotor field control. In contrast, this configuration is ideal when making identical amplitude multiple phase AC voltages that will be driving a common load.

This is very unclear and confused.

"Normal Amp AC" could be anywhere from 5 to 5000, or even wider range.

Generally you can't reduce (by much, anyway) both the current and voltage to a motor.

What proportion of the total loads is 220 VAC versus 24 VDC?

"As many as possible"? Hundreds, thousands, millions?

Why would the answer differ for a 10-hp versus 5-hp motor?

Guidance: please state what it is actually that you are trying to do, in engineering terms.

Most common engine driven welders have the ability to produce power on both the line level AC auxiliary power outputs and the welding level DC ranges simultaneously.

24 VDC at 60 amps would not be a problem for the welding output while still supplying 240 VAC on the auxiliary power outputs.

Use the alternator from a small gen set for the AC, then rectify the AC to give you the DC you are looking for. Automotive alternators produce AC internally, but they are very sensitive to rotation speed, generally requiring a lot more speed than a conventional gen set.

If I may understand U properly, confirm U are designing and the project is still at the design level? I will suggest U take some leave and think about what u intend to do or showcase and what it will mean to Ur prospective users or targeted audience.

U project is in design level and Ur already searching the globe for the above items.

Any design that is not 70% local content in terms of raw material and total cost is already in problem.

What U want is available, U can also achieve that by using a generator and a converter or U may have to work on some available Miller welding machines since they meet Ur specifications.

Secondly 5 or 10HP is the power rating of Ur motor, what do u want to reduce here and at the same time achieve high performance of Ur intended design. The possibility is remote. U can only reduce the size of the motor.

Selecting drivers or starting procedures are different from reducing any other parameters permanently and yet maintaining a large size motor.

DICKSON

Dear Lawrence,

Go back to basics, know that 1 electrical horsepower = 746 Watts. Neither alternators or motors are 100% efficient and shaft horsepower for a motor can be expressed as HP = (Volts * Amps)/ (746 / efficiency), and Volts * Amps is the DC input power used by the motor. You can of course use the AC voltage output from single or three phase alternator winding(s), but if you also rectify this AC voltage for DC loads , the switching transients will appear on the AC outputs as near zero volt crossing noise that you will have to live with. Conventional DC motors use commutators with brushes and carry a friction, size, weight, and noise penalty over modern permanent magnet 3 phase AC motors. You must provide much more information if you want to determine drive requirements etc. Include the nature of the loads, speed requirements and starting torque loads as a minimum. Don't forget to explain the particulars of the alternator driver and number of phases required. How much money you have can then answer the question of maximum quantities. BTY what is this for?

Luther M

dear Lawrence, what do u want to do??? from where u use the power? is it come from generator? or electric motor? in both case u can use 220 Alternator.it maybe 1 PH or 3 PH. after got the AC power u should use transformer for drop the voltage and rise the Amps. because V=IR. if u want to get 60 Amps then u have to use 15 Amps diode or high in bridge for DC. but if u want to use the DC against battery then u have to use a good filter. u can mail me at subha_rya@yahoo.co.in subhajit

Lyn has lots of good advice , as do some of the others. However, there's an expensive way to do this, and a cheap way to do this.

Get a 220v generator which is significantly overpowered for your load, and belt on a self regulated automotive alternator. It sorta dictates that you need to get an electric start machine tho', as there needs to be a dedicated drive on the 'front' of the engine for this, and you really don't want a recoil starter in the way.

This is the cheap way. The cruncher is your need for 24v.

Here in OZ we have a couple of companies which produce diesel powered 24v gensets for the marine industry, but that's not a problem, 'cause they use industrial engines as the donor, and they come with a fan and radiator, which is discarded in the marinisation. They run to 120a output @24v If you used one of these, you could apply an inverter to handle the AC load.

If you wanted a few of these you maybe could start a business in OEM manufacture?

Cheers,

Stu.

What is the available prime mover:Diesel, gas, natural gas, propane, electric, fuel cell,solar, wind?

Must have this information to proceed.

If electric, all you need is a rectifier system and voltage regulator(s).

A generator or alternator of the requested size (10HP) will require approximately twice as much HP input as you expect out.Larger motor/gen. sytems are more efficient, but not much.

More info needed.

HTRN