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# How can i increase amperes ?

I am making a college project for science fair, and i have made a generator with DC motor of 24v, 0.33 amp and 7.92 watt. When i rotate the motor it gives 24-27 volt of dc voltage. Now i want to convert that DC voltage into AC by connecting a converter of 12 volt, 7 amp. I have made i rectifier which converts the 24 dc into 12 dc voltage, but when the converter does not start. Can you please tell me what may be the faults? If the apms are less, can i increase the amps? If the amps are 0.33 can i increase them to 7 amps?

## Comments

Best Answer 4 years ago

Well you just can't convert 24 volts, 0.33 amps, 7.92 watts, to 12 volts, 7 amps, 84 watts, no mater what you do.

24 x 0.33 = 7.92

12 x 7 = 84

Even at 100% the best you can do is 12 volts 0.66 amps.

To get 7 amps you need to reduce the voltage to 1.13 volts.

Answer 4 years ago

If i reduce the voltage, the converter which needs 12 volts and 7 amps to run will not function.

Now what about if i uses a dc motor of 24 volts, 200 watts which will be of 8.33 amps, will it be possible that the converter can convert the DC voltage of around 24-27 volt into AC voltage.

Answer 4 years ago

That might work.

At 50% efficiency you get 100 watts and that should be plenty to run a 84 watt circuit.

Remember since you are using a motor as a generator at best you can produce 50% of the motors capacity.

Answer 4 years ago

"Remember since you are using a motor as a generator at best you can produce 50% of the motors capacity."

I don't disagree, but why is that? What losses are present inside a motor being used as a generator? Is it because the output mechanical power is 80%ish less than the input electrical power due to losses and running it the other way (maximum nominal speed and mechanical power) and that 20%ish loss goes the other way?

Answer 4 years ago

Sorry for taking so long I was on the road.

Car alternators are only 50 to 60% and they are made for generating electricity, most high efficiency generators only produce 80%.

Without knowing the motor or conducting tests on the motor 50% is giving it some benefit of the doubt.

Answer 4 years ago

Thank you sir for your reply.

According to you motor is not better equipment to produce voltage. From best of your knowledge can you please suggest me another thing of better result?

Answer 4 years ago

Thanks Sir, for your valuable suggestion. Any other suggestion for me.

Moreover can you please tell me about another college project which can astonish my teachers.

4 years ago

What are these amps going into ?

A drawing would help a lot to answering your Question..

Some basic understanding, a machine (DC motor) that runs on one third of an amp CAN NOT deliver 7 (seven) amps as a generator.