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Discussion Starter · #1 ·
These are some great batteries. They charge fast are lite weight and they are 18v and 3amp hour. On a Aristo Pacific I get almost 3 hours with lights and sound and 2 hours with smoke and lights and sound. They fit in tenders and the double door box cars great. Have 12 already and can recharge at any time. Jake http://www.tylertool.com/makita56.html
 

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Yep, look like nice batteries, but at $80 each, don't know that they are really that exceptionally priced. I would not say great, would say reasonable. Remember that the Aristo batteries have per cell monitoring in the pack, a lot more protection, so you get a few more things, like smaller size.


Regards, Greg
 

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yes you can't really beat Li-Ion for weight/size, and you can't beat NiMh for value...as long as you got the room. I got NiMh's stuffed in most of my tenders! :D
 

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Torby
I have been using the 7.2v version of those from "all battery" for a couple years now. It is a great value. I also use a few li-ion but only when I have a space problem.
 

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Trying to figure out how to cram one of those IED's into my Annie's tender.
 

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Discussion Starter · #8 ·
Greg, At the current sale price I agree. But it you watch this site they go on sale for $99.00 at times. They have all the protection built in and they full charge in about an hour with the makita charger. Two batteries can be charged at once so when one needs to be changed there's a charged one ready to go. This is great for shows. Attach in the tender with alligator clips and your good to go. I have tried all types of battery packs and most take up to 4 hours to charge. One other plus is they have a 2 year warrenty and they replace no questions asked, I even dropped one on a concrete slab and they said send it in and they covered it. Because the charger has temp sensor as it charges and conditions the battery and shuts down when complete it makes it worry free. And since its LI-ON once charged it will stay fully charged for months where the others start draining the minute you take them off the charger. Also your site has allot of great info. Thanks Jake
 

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here's what i use for my battery boxcars wire em in series with wire set also sold on that site. Works great most of my runs are an hour or less never have tested (at least not yet) how long they will run. The Regal
http://www.all-battery.com/ProductImages/nicd-pack/Nicd7.2V2400x2.jpg And they are nicads which to me are safer .Believe only $26 for two!!! 2400mah
 

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They're wired in series so they're just 1 19.2v battery.
 

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please explain, I'm electronically stupid! Do you need a diode or rectifier etc.?

HOW?

got a picture? lol
 

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Jake, at $50 that is a deal, I will agree. The 2 year warranty is also a bonus.

Looking at that price and with the additional information, I would agree that it's a good deal.

(Home Depot sells Rigid tools, and they have a LIFETIME warranty on their batteries. I'm not sure you can get that warranty if you buy a charger and battery combination alone, but it's something to consider also).

Regards, Greg
 

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Posted By Biblegrove RR on 02/07/2009 11:37 AM
please explain, I'm electronically stupid! Do you need a diode or rectifier etc.?

HOW?

got a picture? lol


Diode and rectifier are essentially the same thing. They both pass electricity in one direction only.

The term Rectifier is usually used to mean a device that is converting Alternating Current (AC) to Direct Current (DC) by allowing the current to pass only when the polarity is one direction... thus you lose 1/2 of each cycle of power. Through correct usage of 4 diodes you can get both halves of the AC cycle and that is called a bridge rectifier.

The term Diode (means "Two Terminal") is usually used when you are working with very small power amounts (Radio signal detection, etc.) or where you are just attempting to let small currents flow in one direction and block possible currents in the other. With putting two batteries in parallel a diode (or rectifier) is placed in one lead of of each battery to allow current to leave the battery but block current from the other battery from flowing back into it.

If somebody doesn't beat me to it, I will go make a couple of drawings of what this is about.

The symbol in a schematic of an electrical circuit is a circle with an arrowhead against a flat line. By the way, the arrow head of the schematic symbol for a diode represents a "Cat whisker". The first diodes were a hunk of galenite crystal sitting in a pool of Mercury, the pool of Mercury being one connection to the circuit. And a thin sharp pointed wire that was poked at some place on the crystal. Where the wire touches the crystal, the pressure of the wire point causes the phenomena of passing current in one direction only between the crystal and the wire.
The older engineers will talk about "Conventional Current" flow and say that "Current" flows in the direction of the arrow.

UNFORTUNATELY, this is now known to be backward from what is actually happening in "Electron Current" flow. Years ago when electricity was first being understood they had a 50/50 chance of knowing which way it was flowing and they guessed wrong. They labeled a battery cell as having an excess of "electricity" on one terminal and that it "flowed" out of a battery and into the other terminal. They thus labeled the one they thought had the excess as "Positive" and the other as "Negative". They then said that a Diode allows current to flow from the "Positive" terminal to the "Negative" one. Thus the arrow also pointed that way. Too bad... Electricity is actually Electrons flowing from the Negative terminal to the Positive and thus it is flowing the opposite way that the arrow is pointing.

Anyway, if you want to use a diode (rectifier) to prohibit electron flow INTO a battery, you arrange the diode so that electrons cannot go into the Negative terminal OR out of the Positive terminal. From an electronics point of view, it doesn't matter which lead of the battery the diode is attached to as long as it is pointing the right direction to stop current flow in the wrong direction... from a practical point of view it is usually put into the same lead on all the batteries in a device. There may be some nuclear physics point of view that would say it is better in one lead than the other; I have heard it argued, I just don't remember what was determined to be the best.
 

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Well Greg beat me to the Bridge schematic, but here is mine anyway. Sure hope I got the polarities right on everything, I think I reversed every symbol at least 2 or 3 times!


Follow the red and green arrows and notice that no matter which way the current is flowing in the AC side it is just one way in the DC side.
 

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Short of time now.

I'll explain tomorrow.
 

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Discussion Starter · #18 ·
OK, a question then on the bridge rectifier. I have 2 of the old Lionel ZW transformers in mint condition (mother-in-law used to work for Lionel after WWII in Irvington NJ 1 block from where Aristo is now) that are not being used. Can I use these with the bridge rectifier and if so what size and how to hook up and what voltage and amperage is expected ?? Thanks Jake
 

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Well, Greg and I both missed indicating something that would be needed in addition to the bridge rectifier... the output is labeled as 'DC' but that is actually a pulsing Direct Current, also known as full wave rectified AC. It may all be current flowing one direction, but it is surging at 120 surges per second, going from 0-Volts to Max Voltage at twice the AC line frequency(120 surges per second for 60 Hz line frequency).

You would need to add some filtering to the output to smooth the pulses out to a flat Direct Current. The filter would be a pair of capacitors and a large inductor (coil). The inductor kind of smooths out the peaks and the capacitors hold a charge to fill in the gaps between, the combination of the two will smooth the voltage and current out. Without the filtering it might run a DC motor okay, but a sound card (you'll get a lousy 120Hz "hum" in the output at a minimum and total loss of control of what sounds play and when!) and fancy electronics to control lights or on-board speed control would probably go nuts.

Now you are gonna ask what size capacitors and what size coil...right?


Ugh! Now we are into actual design and not just the theory that I am struggling to remember.


The size of the components (capacitor, inductor, and rectifiers) will depend on what maximum current and voltage is to be supplied. The number of filter stages will determine just how pure the DC will be... one stage of filtering will leave a volt or two of ripple on it, which is still probablly unnacceptable for modern electronics in the train controller and especially in a sound card!

A high response rate Voltage regulator on the output might help with the ripple, but a second or third stage of filtering would help too.

Theory says.... the maximum DC that can be supplied will be about 0.707 times the maximum AC voltage. minus the losses in the bridge rectifier and the filter components (a few Volts per filter stage) and the current will be about what the AC transformers are rated at as long as the filter components can handled it.


Dain'g yer still wanting to know what components, ain't ya?!

I fear that is beyond me at the moment... if you are intent upon using the transformers you have, supply their ratings here and I will see if I can resurect the forumlas someplace... but I think this may be more expensive and "TROUBLE" than buying a power supply built by someone for the purpose... not that it cannot be done, but you need to be intent on doing it before you decide to start and if you don't know exactly what is needed or how to calculate it yourself then you are treading in difficult waters.
 
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