Power requirements in amp hours for project

[ararrati]

Hi guys,
I have been working on an automation of a cart. The cart wheels are producing a current of 14 Amps for 5 minutes for every cycle(1.16 Amp hour stored in a battery). while the cart is running there are 2 actuators operating. One actuator uses 10 amps for 5 seconds (only 0.01388 A*h??for every cycle) and the other one 1.3 amps for 26 seconds (.001 A*h only?? for every cycle). Are my conversions correct? The cart seems to be producing much more amps hour than what I am actually using?

 

[berkeman]

Hi guys,
I have been working on an automation of a cart. The cart wheels are producing a current of 14 Amps for 5 minutes for every cycle(1.16 Amp hour stored in a battery). while the cart is running there are 2 actuators operating. One actuator uses 10 amps for 5 seconds (only 0.01388 A*h??for every cycle) and the other one 1.3 amps for 26 seconds (.001 A*h only?? for every cycle). Are my conversions correct? The cart seems to be producing much more amps hour than what I am actually using?

How does a cart *produce* power? Do you mean it needs those power numbers to move? What voltage is your battery?

 

[ararrati]

Hi berkeman,
there is an alternator attached to a wheel which produces electrical charge. Cart moves through a winch. I am planning on installing 3 * 125A.h 12V batteries. Power numbers are for opening gates in the cart. The cart is fairly large (10 tons).

 

[berkeman]

Hi berkeman,
there is an alternator attached to a wheel which produces electrical charge. Cart moves through a winch. I am planning on installing 3 * 125A.h 12V batteries. Power numbers are for opening gates in the cart. The cart is fairly large (10 tons).

Wow. Can you give some context to your question? Can you post some pictures? I have trouble understanding why there is a winch-driven cart generating and storing electricity. Thanks.

 

[Averagesupernova]

Berkeman, have you gotten the disease that seems to grow here on pf? :) I have noticed that what seems to me to be enough information in various posts is often thought by other members not enough. Nothing wrong with plain old curiosity though. I recall starting a thread one time wondering if a certain part existed off-the-shelf based on my loose description. Some folks were very helpful, others were not. Would not help unless I gave a detailed description of the whole project. One member (no longer a member) went so far as to say my way of thinking is why planes crash, nuke plants blow up, etc. etc.
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Now to answer the OP. There is nothing to say that you cannot charge a lead-acid car battery (for instance) more than you are taking out of it. There is a limit to this of course. I don't think 14 amps in a typical car battery in cycles is that big of a deal. Of course you have not said how long the cycle is. You say 5 minutes of charging, but have not mentioned how much down time.
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Edit: I am curious too about just what the whole project involves.

 

[berkeman]

Sorry if I'm being overly dense, but I still have no idea what a winch-driven cart is, and why/how it would generate energy...

 

[AlephZero]

I'm imagining something like this, with doors for the loading and unloading mechanism that are "self-powered."

There are the remains of a 150-year-old rail line near where I live, which had ten cable-operated inclines powered by stationary steam engines in a distance of 30 miles, with the steepest gradients about 1 in 8. The "road" down this hill (continuing along the right hand side of the water reservoir in the distance) used to be a part of the track.

 

[ararrati]

Yes, it is exactly the same idea alephzero pictured. The cycle is 120 times/day. So, 5 min charging and 7 minutes down time. The idea is to not have an operator near the cart when the doors open and unload.

 

[berkeman]

Ah, thanks Aleph!

@ararrati -- can you just use the winch itself for re-generating power on the descent? Or is that what you intend? Put the battery circuitry at the winch at the top of the hill... Are there also counter-weights to equal the weight of the empty cart?

 

[Averagesupernova]

He needs power ON the cart and cannot run electrical wires to the cart.

 

[ararrati]

Yes, the cart goes over blast furnaces which temperature may reach over 200 F. So cables are undesirable. electrical/mechanical components will be on the cart (isolated and cooled).

 

[jim hardy]

So the batteries are just powering something on the cart, and that something is NOT the latch solenoids that control its motion up and down the hill, nor the winch that does the work of pulling the cart up the hill ?

I trust that when power is off those "latch" actuators go the "latched" position , that is they grab the winch cable or do something else to stop the cart, else you have a runaway cart .

Observe elevator brakes:
http://www.warnerelectric.com/elevator-brakes.asp
http://www.msha.gov/S&HINFO/TECHRPT/HOIST/PAPER5.HTM
http://www.mayr.com/fileadmin/user_upload/Branchen/Elevator_Brakes.pdf
http://www.mayr.com/en/products/safety-brakes/

Since i don't know what it is you are powering i felt obliged to caution about elevator safety.
Hope it was wasted effort.

If you're just opening gates to dump the load, surely it's "energize to dump" ?

old jim