Dual Direction Electric Generator

So, you have some mechanism that has some waste that you see, and you want to harvest it? This waste is in the form of reciprocal linear motion, the extension and frequency are both irregular?

Is this generator scheme of yours a sacred cow? That is to ask, are there other harvest schemes that you might consider, or are you stuck on finding this ratcheting high-loss motor-cum-generator idea?

We have build a wave carpet: http://taflab.berkeley.edu/uc-berkeley-ocean-wave-energy-converter/ We want to transform the linear motion produced by the wave fluctuation into rotational motion and convert that into electrical energy.

???

Your linked page tells me that the system already uses pumped storage hydro to harvest electricity, which I believe is one of the better ideas for wave energy harvest.

Wave energy harvest schemes are viewed around here with a jaundiced eye, and rightly so: most we are presented with are WAY more scheme than energy harvest.

Your wave carpet and pumped hydro storage seems like a pretty good idea... if it really can withstand the unkind environment in which it operates.

The problem with the pump system is the the damping is not linear. This is making it very difficult to measure the energy output. We are trying a new method of energy measurements, and because electrical energy is the end output goal, we thought why not hook it up directly.

If you are looking for usable electrical energy why are you looking for "new methods" for energy measurement?

"This is making it very difficult to measure the energy output."

How about volume of water lifted, vertical lift, and time?

That happened to be the exact way we measured it before. We just want to have a new method now so that we can confirm our results.

Your hydraulic connections are a mystery, but basically you have a set of double-action pumps with a common outlet. You use the flow from that outlet to drive a turbine, which drives a generator in a single direction, and you then measure the output of the generator and relate it to the measured vertical movements of the pumps. Job done.

This is what we have already done. But energy is lost in the system do to the pipes and the pump. We were wondering if we could directly hook up a mechanical system that would obtain the energy with less loss.

A pair of one way slip clutches would do you more oog bing id set up properly they will keep the generator spinning the same direction regardless of the stroke length or direction.

That setup alone will solve a lot of your problems.

Sealed Sprag Clutches would be something to look at.

You will probably have to design and build a generator like this.....You could have the up motion turn the rotor and the down motion turn the stator, that way you are essentially turning the generator one direction...2 opposing ratcheting systems...I believe it would be a unique design....I don't see this ever becoming cost effective....

While researching generators we called a company and they told us that a motor like this might work: http://catalog.orientalmotor.com/item/all-categories/smk-series-low-speed-synchronous-motors/smk5100a-aa?plpver=11&categid=100&prodid=3001052&origin=keyword It has three cables. One will output energy while the motor spins in one direction, and the other will output with the motor spins in the other direction, and the third is a ground. Is this a possible set up?

No clue....but I will say that using a piece of equipment for something other than it's intended purpose usually does not pan out....and there's the loss of momentum switching directions, this may result in overheating....

Duplicate thread.

I'm stunned too, good answer, I was about to sugest a brushless AC servomotor with a 3phase rectifier bridge, and then you measure your amps and volts as usual.

Does this include a diode bridge?

What does a diode bridge do?

Ha, ha. Good one.

_{(I hope you're being funny.})

A diode bridge converts a positive and negative voltage waveform to a positive or negative voltage waveform. [You really cannot find an electrical engineer, student or professor at Berkely? That sounds very strange to me.] For your concerns this will mean that regardless of your dynamo spinning clockwise or counterclockwise the output voltage will always be the same. For multiple reasons (pun intended) I suggest that you consider looking at the poly-phase system one finds in an automotive alternator. The mechanical loading will be smoother on whatever mechanism turns your water flow into dynamo spin.

A diode bridge lets the little electrons go over the river and not fall in.

But they can't go home again.

Dear Redfred.

actually it was the very basic thing to explain the function of the bridge rectifier its used to convert the AC to DC and you can find it at the secondary coil of every AC/DC power supply or on the car alternator .

Why not attach several linear elements to a crank, just like any engine?

Would this work with varying wave nights? Would a crank only work for a certain range of aptitudes?

Sorry for the typo. Will a crank shaft work for different amplitudes of waves? If the wave amplitudes are too small they will not be able to push the crank shaft to perform a full rotation. Is there a way to avoid this?

This will always be a problem...think of no waves. A crank could work and maybe a flywheel to maintain momentum?

Lyn says it won't work.....he may have said why, but I wasn't really paying attention...

You NEVER listen to me!

Consider the inertia of a spinning armature. Now, consider the energy required to stop the armature, spin it up in the other direction enough to generate some power.

I also don't understand the need for a "calibrated" motor. Just measure the output and be done with it.

I'm skeptical of this whole thing.

How complicated do you want to have this?

Motion in a magnetic field produces electricity. So why not using a swimmer and a coil and measure it this way. This will cover all amplitudes.

A linear generator will do.

Have fun!

As a student 50 years ago, I had studied Rosenberg generator used in railway coaches to charge the lead acid batteries. After the advent of silicon rectifiers they have become obsolete

Yes worthy of scrutiny....

http://en.wikipedia.org/wiki/Metadyne

since long the people are doing the experimenting to generate the power from sea waves and by my point of view the linear generator with spring return will be the best idea .

and the minimum lose of energy .a cylindrical coil and shaft with the permanent magnets will work well for it .the vertical installation of the linear generator will make it more efficient the wave will rise the shaft and the wave+gravity(and the weight of shaft of course )+the spring will return it .

so the return to the direction of ground will be more force-full then the rising ,so you can use the 2 linear generators parallel and and engagement system to downward movement to get the double force .

i hope you guys will forgive me for my poor English.

I need to ask, why are you investing sums of money in a 60 year old project that has proven to be inefficient? There are many wave generators built and operating and none very successfully. They worked on hydraulics, pneumatics, air pressure from blow holes and it was not efficient.

With a rack and pinion you loose direct energy by operating through a mechanical movement, which has major limitations. The rack having additional forces applied at each neutral moment when you try to reverse the generator on each stroke of the rack.

Additionally, waves do not carry forward in a uniform manner and set duration of time, therefore the forces exerted on the rack, in a mid stroke, when a rouge wave hits the carpet would inevitably strip the rack or bend it or snap it out of its mounting frame.

By the time one has found a manufacturer of the generator you are seeking, the costs would outweigh any conventional generator costs that could be spun by a piston and con rod. Besides this, there are easier, cheaper and more cost effective ways to generate electrical power at sea rather than from the seas.

If you want to play with an action that changes reciprocal motion to rotary, check out the Nordic Track ... the reciprocal motion of the skis keeps the flywheel spinning on the same direction via clutches...the length of the stroke makes no difference.

Why not design the rack and pinion setup so that no matter the direction of the rack motion it rotates the generator in the same direction regardless. Two racks, two gears, two unidirectional bearings(or one way clutches, whatever you want). Then you don't have to reverse to direction of the generator and you can harvest the momentum of the generator parts instead of fighting them.

This works on a linear drive and rotates in one direction. Would generate on the down stroke and given enough inertia would continue to run during the upstroke. Generate DC and use inverter.

Hello pal:

Here you go, forget about ratcheting devices with clutches, too much loses, read also my post ## in this thread.

Here you can se what a full bridge rectifier does, and how it will supply positive voltage to your load regardless of your servo motor (now working as a generator) rotational changes.

Regards

We ocean engineers find all of this to be very strange.

With distance down below the wave train, the orbital motion from which energy may be extracted diminishes; i. e., the greatest energy potential is at the surface, not at some shallow bottom location.

The future of wave energy extraction is to do so with an enhancement of pay-back by placing energy extraction systems at the surface on near-shore locations where rising sea level and storm driven tides and waves are incurring erosional attrition of the super-tidal beach and uplands (most of the east coast of the USA and some of the west coast). The design and sizing of the extraction devices should be to withstand and achieve the highest percentage of energy extraction under the most severe sea state conditions.

Finally, blanketing the bottom has all manner of impacts to biota of the benthos, as well as alterations of turbidity and bed load of sediments that will be in suspension.

imfisher - change your fundamental direction of problem solution to include the preceding. The first to come up with a system that works will get a Nobel in engineering, if one should ever exist.

USEPA has a grant that, if pursued with the dual purposed I have discussed, may be a worthwhile venture for you. If interested, email --

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Maybe look in this type of generator. https://www.google.ca/search?q=toyota+linear+generator&biw=1152&bih=739&tbm=isch&tbo=u&source=univ&sa=X&ei=EBNRVPn8L4m8yQS844LwBQ&sqi=2&ved=0CEIQsAQ

You could cover the oceanic "Garbage Patch" with this so as not to be a complete waste:

Why not forget the rotary motion and just use a linear alternator?

I have one of these (which I just learned is called a Faraday Flashlight) in my glove compartment which uses that principle (principal?).

You need a WIRO (whatever input rotational output). This has already been invented , and readily converts wave motion to rotational energy (and hence to electric power).