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Topic: PWM 12V 150Amps output signal using arduino is it possible ???? (Read 4772 times) previous topic - next topic

fungus

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

DuncanC


Does arduino capable of output 12V and 150amps PWM signal ??? if not can anyone make me plan of using micro-controller in PWM 150 amps output.. what I mean that I want to use micro-controller in developing PWM circuit that can output  of 30- 150amps/12v . where the amps can be assigned and controlled in the sketch of micro-controller frequency as well.


Let's make sure we understand each other.

The Arduino is a low power device. It has several PWM outputs at 5 volts and around 20-40 mA.

It cannot output any more than that. Period.

However, you should be able to build an amplifier circuit that will take the logic-level outputs of an Arduino and turn them to high power 12 volt output. Some high power MOSFET transistors with very low internal resistance.

Varying the output current is also possible. You'd need to build a current limited power supply that can be digitally controlled.

I'm not an EE, I'm a software guy. I can't design these circuits myself, but I know enough to know basically how they would work, and how to search for the correct information.

Now, as to the purpose of your project: You're looking to split water into hydrogen and oxygen? Bear in mind that every step in a system like this has some amount of inefficiency. (According to the second law of thermodynamics, converting energy from one form to another always results in some losses to heat.)
A car's gas engine is quite inefficient. It only turns about 20% of the energy in Gasoline into useful work if I remember correctly. The rest is lost as heat.

If you want to split water using a car, you have to first burn gas and convert the energy into rotational energy, at a huge loss. Then you have to convert that rotational energy into electricity using the car's alternator. (Again at a pretty substantial loss.) Then you need to switch and manipulate that electricity to vary the current and pulse width, with MORE loss. Finally, you use that energy to split water into hydrogen and oxygen. That part is fairly efficient, but does still have losses to heat.

You will only get a single-digit percentage of the energy in gasoline stored in your output hydrogen. Most of the energy will be lost.

Another problem:

A car's alternator is not designed to put out 150+ amps of power continuously. You will likely overheat and burn out the alternator in a fairly short period if you do run it at that level of load constantly. In fact I doubt if a car's alternator is even rate for a peak current of 150 amps. That's a LOT of juice. A car's battery can put of that kind of current for brief periods, but not continuously.

MarkT

Splitting water with electricity isn't great efficiency either.  High power PWM is
efficient though, >95% isn't implausible.

Thinking about it PWM won't work either, as you get side-reactions if the voltage is too
high (even for a short time).

So you need a buck-converter topology, an inductor capable of 150A at efficient PWM
frequencies is going to have to be wound yourself using litz wire I reckon.

Since the potential to split water is about 1.2V, think many 1000's of amps for electrolysis
on a scale to help power a car - in practice stacks of cells are put in series so the current
is lower and the voltage higher.  Perhaps you just need 8 or so cells in series from 12V?
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

Pelleplutt

1. http://www.youtube.com/watch?v=QV-OBwXKthY
2. http://www.instructables.com/id/How-to-assemble-a-HHO-Generator-and-why-it-works/

1. Are Mythbuster always right?
2 Do not belive all on the net!

The theory is it should help the gasolin burn faster.

I think it's BS

Pelle

polymorph

I seem to recall that the maximum efficiency of electrolysis of water is only about 70%. And that the maximum theoretical efficiency of the Carnot cycle in an engine is just under 70%, but the actual efficiency in modern engines is considerably lower.

So already 50% of the power is gone. IE, 2hp (about 1500W) from the alternator nets about 1hp additional power at the engine. Then the alternator is not 100% efficient. The battery is not 100% efficient at storing and releasing power.

Even if everything was 100% efficient, you'd have broken even.

BTW, there is no such thing as "HHO gas". It is H2 and O2 mixed.
Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - https://tinyurl.com/Technote8
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

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