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Advantage Hobby . Revolution Models . CarbonXtreme

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Align T-REX 600N 700N > Voltage Regulator: Align 2 in 1 or Fromeco?
 
 
Ace Dude
Elite Veteran
Location: USA

Quote 
Who said you cant ? The 611 manual says 6.0v.

Actually, Futaba says so:

http://www.gpmd.com/cgi-bin/wgpinf100p?&I=FUTM0825



06-21-2007 Over year old.
 
 
Ticidytoc
Senior Heliman
Location: Los Angeles, Ca.

Quote 
(higher voltage could damage the servo)

Meaning running at 6.0v will wear out the servo faster. This is why I run a diode, no need to prematurely wear out my servo motor.
06-21-2007 Over year old.
 
 
JeffM1999
Senior Heliman
Location: Thornton, CO

LOL, did anyone see that pic of Alan Szabo Jr. on that Duralite webpage? Pretty old. He was still flying Airtronics and Raptors. My how things have changed since then.

Anyway, I would say that the Arizona is nice, but it is pretty bulky. I don't have the Align to compare it to. Anyone help me out there? I like the pin flag switch option on the Arizona. It is one more thing to possibly lose at the field, but it is nice to know that if it fails, everything will just stay on.

I thought the 9252s were 4.8v only, that one kinda surprised me.

Definitely only run the 611/9256 at 4.8-5.1v. Or run an inline reg for the servo, like others have mentioned. The Amp and sensor can handle 6v, but the servo won't for long.

________________
Magnum Fuels
06-21-2007 Over year old.
 
 
JeffM1999
Senior Heliman
Location: Thornton, CO

One more thing I just thought of. Why would you even want to run the amp and sensor at 6v anyway. Its not like a servo where you are going to get extra speed or anything out of the amp/sensor anyway, so why mess with it?

________________
Magnum Fuels
06-21-2007 Over year old.
 
 
MJWS
Key Veteran
Location: Airdrie, AB - Canada

OK. Time to get down and dirty.

Servo motors run on Watts. (Volts * Amps)

The Fromeco regulator is LINEAR. That means it converts the uneeded excess voltage to heat. So if there is 7.4V coming from the pack and you are set to 6V regulated with a 1 amp load (6 watts) you will need to waste (1.4V * 1A) 1.4 watts of energy. Thus the super huge heat sinks to handle large currents.

With ALL linear regulators the mah available is fixed by the pack. Doesn't matter if it is 5 cell nimh at 6V or a Lipo at 8.4V. 2000mah is 2000mah is 2000mah. The excess voltage just makes the system work harder as it must be burned off. There are NO gains to run time by using higher voltage lipos. The gains come from larger lighter packs with more mah because we can use lithium chemistry.

The Align Regulator is also LINEAR. Linear regulators have an advantage in that they typically produce little or no radio interference and they are incredibly robust and cheap to build. Downside is they can't handle very high voltages as everything not needed is burned as heat.

Switched regulators are another animal completely. The Ultimate BEC, PARKBEC, and DURALITE regulators are all switching regulators. These regulators can convert voltages very efficiently (~95% for a good one).

With a switched regulator when we ask for the same 6w (6V * 1A) load, it will only draw the current it needs to from the pack. So at 8.4V it will only need 6w / 8.4v = 0.71A (+5% loss) so .75A instead of the full amp of current. So we gain ~25% more available capacity at 8.4V (2s) instead of a 6V pack with both being 2000mah. Combine that with the fact that we can run larger lipo packs for the same weight and it is a huge bonus.

With a good switcher you can actualy run a tiny 3s pack and get long runtimes. Same Load: 6w / 12.6V = .47A (loss excluded) so a 1000mah 3s pack will last roughly as long as a 6V 2000mah pack.

LiPo vs LiIon? We run $10,000 dollar GS planes and 5000w heli's on the Lipos some are supposedly afraid of. LiIon is NOT SAFER than LiPo. When they vent it is far more violent. LiPo was developed to help deal with that (and other reasons). LiIons become safer when they have safety circuitry built in and dedicated chargers. Unfortunately we tend to remove all the protective devices when using lipo's. (Read about that somewhere else. Try RCGROUPS.) The lipos's are getting used because they are common and capable of much higher current. I have 800mah lipos that can match duralites 4000mah LiIOn packs in terms of current capacity and weigh 1/6th.

Someone else can hit the peaked voltages on good 4 cell and 5 cell NIMH packs. It sure as hell aint 4.8V. Which would be why many 4.8V servos are extremely happy on 6V REGULATED. With a tail servo you take your life in your hands as they are on the ragged edge of high performance. They draw a ton more current under higher voltage. That makes heat. Heat kills em.

The 611 Amp is happy to 6.0V in the manual. By that a 5 cell nimh pack is inferred (7.8V+ peaked). The 9256 is only rated at 4.8V a 4 cell nimh is inferred. (6V peaked) That surface charge is gone fairly quickly under normal use. So the 9256 would run at around 5.5-5.2 for much of the charge.

Good Luck,

Mike
06-22-2007 Over year old.
 
 
JeffM1999
Senior Heliman
Location: Thornton, CO

Thanks for the info MJWS. I was under the impression that the Arizona was a switching reg, but I guess it never clicked that the HUGE heatsink was probably there for a reason.

I have both the Duralite 7.5A, 5.1v reg and the Arizona reg. I was debating which one I shouild put into my new 600N. I had decided on the Arizona because I think the switch on the Duralite is crap, and I really like the pin flag switch on the Arizona, but your post has made me rethink it. Which one do you recommend that I run?

Sorry for 'hijacking', but I still think this is relevant to the thread, and others might find it useful here, too.

Cheers!

________________
Magnum Fuels
06-22-2007 Over year old.
 
 
BlakeMcBrayer
Elite Veteran
Location: Georgetown, Ky

Myself, I a far bigger fan of a LINEAR regulator. In theory, I do like the efficiency of a switching regulator, but I'd prefer to not risk any possible RF interference. Yea, the LINEARS are not as efficient and give up the extra voltage as heat, but it's almost impossible for them to generate RF.



Quote 
LiIon is NOT SAFER than LiPo.

I do STRONGLY disagree. The chemistry is more stable under normal conditions and it's darn near impossible to get them to vent. Lions have an internal safety (inside the cell can) that will physically break when the cell is being overcharged. This structure is in the power path and when the Lion layers swell within the can from being overcharged, it breaks. This stops the charge before the cell generates enough pressure to vent.

Do me a favor, in a safe plae, hook a Lipo and Lion directly to a 12 volt power source and let me know what happens to each type. I'll be happy to provide you with a few Lion cells for the test, just as long as you video it and post the video.

.

Don't come off the throttle untill you see your GOD!
06-22-2007 Over year old.
 
 
JeffM1999
Senior Heliman
Location: Thornton, CO

Good to know Blake, thanks!

I would gladly give up some battery capacity for the much lower chance of RF interference. Especially since I have a 4800 Relions and 4000 duralite that I will be running on a 50 size machine. Both batts are overkill for me, as far as capacity is concerned. I could probably fly 12 flights on the 4800 and 9 flights on the 4000 before a recharge. My nerves would not be able to handle that many flights in a day anyway!

________________
Magnum Fuels
06-22-2007 Over year old.
 
 
MJWS
Key Veteran
Location: Airdrie, AB - Canada

Personally I think the dual voltages on the Arizona combined with the pin flag switch is pretty hard to beat. I've always found Duralite products superb but over priced. For me it isn't about trying to get as many flights as possible in without recharging. I'm never comfortable flying the middle and bottom of a pack I want to know beyond a shadow of a doubt that I will have reliable consistent power.

I'd MUCH rather run a lighter pack and just field charge it or swap them. The battery is SO accessible on this bird you could say it was designed around the small regulated light pack model. Ten second swap. Plug in a fresh one and fly without carrying dead weight.

The switcher will get you more flight time from your packs. Only downside is the cheap switchers are sometimes terribly noisy electrically. Not an issue on a well designed product like the Duralite.

Btw, the reason you'd run the amp and sensor (611) on 6V instead of the lower voltage is that an inline step down (diode) for a single servo is incredibly elegant and robust solution. The amp and sensor are just as happy on the main bus. The less current we have to drop the less heat we create.

My 600N runs 2s unregulated A123's the voltage is low enough (6.3V) that it performs like the upper middle of a 5 cell pack. But it does it without sagging for 95% of the discharge. 9256 is stepped down. No switches or other crap in the way. Plug in the deans and Fly. Recharge in as little as 8 minutes.

Mike
06-22-2007 Over year old.
 
 
JeffM1999
Senior Heliman
Location: Thornton, CO

That is a nice solution. I guess you would save a bunch of weight if you only had that little step down in-line reg instead of a bulky Arizona or Duralite reg.

Out of the two choices I have, I am leaning towards running the Arizona because of the pin flag switch and also since I just learned about how much less RF it generates.

Thanks!

________________
Magnum Fuels
06-22-2007 Over year old.
 
 
MJWS
Key Veteran
Location: Airdrie, AB - Canada

Here is a nice site for ya Blake. It isn't my opinion I've cited. I agree with you on the linear btw. Simple, cheap, no rf. But a switcher CAN be designed well and do give the flight time advantage.

http://www.batteryuniversity.com/partone-5.htm

Quote 

Lithium-ion-polymer has not caught on as quickly as some analysts had expected. Its superiority to other systems and low manufacturing costs has not been realized. No improvements in capacity gains are achieved - in fact, the capacity is slightly less than that of the standard lithium-ion battery. Lithium-ion-polymer finds its market niche in wafer-thin geometries, such as batteries for credit cards and other such applications.

Advantages

* Very low profile - batteries resembling the profile of a credit card are feasible.
* Flexible form factor - manufacturers are not bound by standard cell formats. With high volume, any reasonable size can be produced economically.
* Lightweight - gelled electrolytes enable simplified packaging by eliminating the metal shell.
* Improved safety - more resistant to overcharge; less chance for electrolyte leakage.

Limitations

* Lower energy density and decreased cycle count compared to lithium-ion.
* Expensive to manufacture.
* No standard sizes. Most cells are produced for high volume consumer markets.
* Higher cost-to-energy ratio than lithium-ion

Mike
06-22-2007 Over year old.
 
 
JeffM1999
Senior Heliman
Location: Thornton, CO

Interesting that they are saying LiPos are safer than Li-Ions....

I have always heard the opposite.

________________
Magnum Fuels
06-22-2007 Over year old.
 
 
MJWS
Key Veteran
Location: Airdrie, AB - Canada

You have to consider that in industry both chemistries get the same protective circuitry. The polymer is soft and designed to vent slow. The Li Ions have a nice little bomb casing if you blow em up right. RC completely messes up the whole deal but some RC Li Ions have protection built in.

It's just information. Take it however you like.

Mike
06-22-2007 Over year old.
 
 
Ace Dude
Elite Veteran
Location: USA

Quote 
LiIon is NOT SAFER than LiPo.

THAT is COMPLETELY wrong. THAT is why Fromeco ONLY sells LiIon RX PACKS.



06-22-2007 Over year old.
 
 
MJWS
Key Veteran
Location: Airdrie, AB - Canada

You would know ACE DUDE. I bow to your far superior knowledge to anyone that actually designs these for a living. Yep You MUST be right. /Sarcasm off

RC anecdote and a couple guys building a regulator. I'll definately consider that the ultimate source of truth. And Btw you've severly misquoted them. Fromeco's peerless line is safer due to circuitry great wise one..

There are only thousands of sites by the industry people that designed and built these citing form factor and safety as primary advantages of the polymer design. Google is your friend.

Here's another. http://www.treehugger.com/files/200...ium_polymer.php

And another
http://www.ulbi.com/engineers.php?ID=4
Quote 
Lithium polymer batteries have comparable energy density to lithium ion batteries and are achieving cost parity. The cells are sealed in a plastic aluminium laminate, so if the battery sees an overcharge condition, the seal ruptures and vents any gases due to electrolyte oxidation and the cell shuts down rather than having steel or aluminium casings fragment, as in the case of lithium ion batteries that may result in metal shards

I can go on all day Mr. Wizard. I bet if you look REALLY Hard you can find some 13 yr old with a slow stick that holds yours. Good for you.

Mike
06-22-2007 Over year old.
 
 
DS 8717
rrProfessor
Location: Here wishing i was somewhere else

http://www.rcbatteryclinic.com/

Heres a very good article on lithium batteries,click on lithium technology.
06-22-2007 Over year old.
 
 
Ace Dude
Elite Veteran
Location: USA

Quote 
You would know ACE DUDE. I bow to your far superior knowledge to anyone that actually designs these for a living. Yep You MUST be right.

Thank you.

Quote 
And Btw you've severly misquoted them. Fromeco's peerless line is safer due to circuitry great wise one..

I didn't misquote anyone. The Peerless line was discontinued a while back. What's your point?

What you don't understand is that LiIon cells contain safety devices to prevent thermal runaway making them much safer than LiPo cells which do not contain such devices.

You can read all about them LiIon cells and the safety devices they contain here:

http://www.rcbatteryclinic.com/lithium-ion.html

The bottom line is that LiIon cells are safer than LiPo cells.



06-22-2007 Over year old.
 
 
Rockohaulic
Elite Veteran
Location: Valencia, CA, USA, 3rd Rock from the Sun

OK - back on track with a stupid question.

Since some Voltage Regulators require you to run an in-line diode for the tail servo anyway, why can't I just do the following:

Run a tried-and-true 5 cell NiMh RX battery, and then step down the voltage to the Tail Servo with the $3.99 diode from Align. I would get my high voltage (6 volts) to my cyclic servos, and the whole thing would only cost about $40!!!!

I got a helicopter for my girlfriend,
It was a good trade!
06-22-2007 Over year old.
 
 
Ace Dude
Elite Veteran
Location: USA

Quote 
Since some Voltage Regulators require you to run an in-line diode for the tail servo anyway, why can't I just do the following

No voltage regulator requires you to run an in-line diode for the tail servo.

Why not just use a 4 cell RX pack? Many folks have used them for years with success.



06-22-2007 Over year old.
 
 
Rockohaulic
Elite Veteran
Location: Valencia, CA, USA, 3rd Rock from the Sun

Can't get the high voltage to the cyclic servos with a 4 cell.

The Align 2 in 1 doesn't step the voltage down to the tail servo, so you have to do it with a diode.

I got a helicopter for my girlfriend,
It was a good trade!
06-22-2007 Over year old.
 
 
4 pages [ <<    <     1      2     ( 3 )     4     NEXT    >> ]2027 viewsPOST REPLY
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Align T-REX 600N 700N > Voltage Regulator: Align 2 in 1 or Fromeco?
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