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Old 10-22-2019, 06:29 PM
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This is on the dreaded F-B site, so Google this:

POWERBOX "IN THE SHOP" AMPERAGE TEST!!
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Old 10-22-2019, 06:31 PM
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Quote:
Originally Posted by wyo69cowboy View Post
I've read more than once what navyguy757 was saying, in that running a regulated voltage keeps servo response the same. For the guys that run HV servos, I've heard of setups using a 3S lipo, regulated to 8 or 8.4V. I also noted PAU's response that his top pilots just swap packs every couple flights to keep the voltage up.


Would a 3S lipo regulated system be a good way to go, if you're worried about keeping voltage constant to the servos? Myself, not being an IMAC or pattern pilot, am pretty sure I wouldn't notice the difference anyway, but am just curious...
On another thread I investigated using 3S regulated, XPS explained the numerous reasons not to do this. I run dual Tattu 5200mah 2S and after 3 15 minute flights still at 8v. Use a larger capacity battery to keep voltage higher longer or as the PAU pro's do recharge often.
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Old 10-22-2019, 07:01 PM
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Originally Posted by Airiley View Post
Most of them have a dropout voltage, some voltage that the battery has to be above the desired output for the regulator to be able to regulate to that point. For example a 6 v regulator with a 1 volt dropout voltage would need 7 volts to be able to regulate to 6. If input voltage falls below 7, I believe output voltage will also start dipping.
What I also believe but not 100 % on, if this is a 5 amp regulator, the output will never go above 5 amps, even in the above dropout condition. (lets assume 5 amps continuous and peak)
There is an entire class of LDO Low Dropout voltage regulators whose input voltage does not need to be much higher than desired output.
Yes, linear voltage regulators should continue to output voltage even when the input voltage is below the desired regulated voltage but the output will be the spec. drop out voltage below the input. Switching regulators are a whole different animal and how they act will be completely dependent on their design. Some will have a spec. input voltage "range" in which they will output the desired voltage. Outside of that voltage range they may just shut down. In some cases the input voltage can actually be below the desired regulated output voltage and the device will still work. Other simpler switchers will work within their spec range and only the mfgr can tell you how they will work outside that range.
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Old 10-22-2019, 10:01 PM
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Originally Posted by eheliflyer View Post
XPS,

I am right with you on most everything you have said here. Except when you are saying that Military uas systems do not use regulated voltage, at least that is what I feel that you were eluding to. In my 14 years as a UAV operator, spanning over 5 different platforms in Tier 2 and Tier 3 size groups, there are always regulators used in these systems. I am not saying you are wrong, but my experience in with assets in an operational environment use regulated voltage.
It's ok I was an AT in the Navy for 6 years, and now am Into facility power more than anything, which I will concede electrical is different than electronics but ohm's law kirchoff's law, inductive reactance and capacitive reactance and time constants are still going to be the same lol.

and while it may be true at this scale regulation does not make sense. you wont find a single facility or industrial equipment that does not have regulated power. well, at least 99% in the US do.

I now that regulators in THESE cases may be NOISIER but the sag I was referring to was the decline of the voltage over time (discharge) as it dips slightly lower than its full charge. it will maintain said set voltage for a longer period of time. however the current pull from sag etc, should not happen if you build it properly. said voltage drop will happen regardless if you cannot handle the amps its pulling, you would obv use a regulator that can handle the output you need say 100a on a RC plane regulator. if they have them that high.
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Old 10-22-2019, 10:44 PM
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Originally Posted by XPS View Post
That's not true, but most of the old archaic systems do use regulation and pretty heat sinks on their products.
it actually is, I suppose saying EVERY powerboard out there does, but there really are only a few at least decently known ones. smart fly has regulated outputs, powerbox has them. even the turnigy ones have them.

Quote:
Originally Posted by XPS
These are modern times. We don't use Futaba S3003 servos with 24oz of torque and Nicad batteries anymore. The reality is that the fewer the "pieces" in your system, the less likely you are to have a failure. Regulators are the number one source of power related failures in RC. As a radio manufacturer for more than decade (the creator of full range 2.4GHz systems for RC) I can tell you I have personally seen many hundreds of regulator systems fail in our customer's setups.
Maybe they failed, but how many were improper usage? just as it was my fault I shorted the battery out on your product does not make it bad does it? I was just a little frustrated it did not have isolated inputs, some others do have a balancing feature that does electrically isolate them, weather its needed or not prob does not matter. some others have that feature.


Quote:
Originally Posted by XPS
Really? Did you do any research on this? Our Arizona corporation filings are within 6 months of each other (SmartFly was 6/26/06, XPS was 1/17/07), but XPS was formed in mid-2005 as a private entity from my RC car company (DEI - where I developed power systems) that was started in 1993. PowerBox Systems GmbH was formed in 2010 from what I can tell.
yes you can claim you were AROUND longer, but you did not produce the powerboard even close to that long. how long has this board been out? I prob should have specified, but the powerbox and smart fly's have been around longer than the x10 or the x24

and fyi smart fly which is Quest Engineering & Development, Inc. has been around since around 1990 or so.

BUT they were not making smart flys then, BUT the smart fly has prob been around longer. as has powerbox. i THINK for the powerboard aspect even powerbox had been around longer as well. granted you may have had the x10 for a while, that i do not know, the x24 though ie) your break into the powerboxes was rather recent was it not?


really though at the end of the day especially since we are on my thread now and not your product group page I am free as a consumer to like or dislike any freaking part of any product out there. I never insulted you directly and in the PRODUCT DISCUSSION section of RC groups I voice my CONSUMER opinion on features that I felt were lacking compared to the competition (smart-fly, powerbox etc).

regardless of how bad I may have been, as a business owner and manufacturer you should have AT MOST offered a simple:

"I am sorry you dislike these features, the reason we feel that it was better to omit those features from our powerboard the x24 is because... blah blah blah

I think you will actually enjoy the product if you give it a chance, test it out on the set up and on ground testing before flight and I am sure you would be happy."


But instead you were wanting me to prove why I should do it that way rather than selling me on why I should change ALL of my planes to x24's THAT alone prevented me from really giving a crap about the product any more.

I will admit I can very argumentative, however it absolutely takes two to tango. with most others varying degree of stances, and have not had to argue with the ones that came about presenting their point differently.

Ironically you still have yet to offer any insight into my use or experience thus far with this product, which I have began to set up spite the issue as I popped it opened and looked for any damage and did not see any. as well as after testing my battery on a series of cycles.

instead you still wanted to ramble and be the right one but most of the time did not explain why you would be the right one in some of the cases. but I guess regardless of how stupid I sounded, or if I was just utterly wrong or not. you neglected the literal cardinal rule of business.

I hope you have enjoyed making a one time customer out of me.


Quote:
Originally Posted by XPS
Ok, care to elaborate? I can certainly explain to you from a engineering standpoint why unregulated power is substantially better for RC systems. Guess which is used in large commercial and military UAV projects. The simple explanation is that removing a regulator removes one more piece of hardware that can fail, but there are many other benefits that direct power provides.
I replied to the one above who also was in the military with essentially the reply to this point here.


On a side note to everyone else on here, thanks for the help and advice for the actual topic on hand. since my experience with the x24 was actually on a different applicable thread ie, the x24 discussion thread on here and rcgroups.
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Old 10-23-2019, 01:34 AM
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Originally Posted by Airiley View Post
XPS, how are you capturing your amp draw ?
I built a telemetry sensor for the XtremeLink radio system that measures voltage and current 10,000 times per second and averages it by 10 (so 1,000 times per second smoothed). The min/max values are stored in EEPROM and the data is sent via the telemetry. You are right in the fact that you need something with a very fast capture rate. Most of the wattmeters measures 1 time per second and average over a longer period of time.
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Old 10-23-2019, 01:36 AM
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Quote:
Originally Posted by eheliflyer View Post
XPS,

I am right with you on most everything you have said here. Except when you are saying that Military uas systems do not use regulated voltage, at least that is what I feel that you were eluding to. In my 14 years as a UAV operator, spanning over 5 different platforms in Tier 2 and Tier 3 size groups, there are always regulators used in these systems. I am not saying you are wrong, but my experience in with assets in an operational environment use regulated voltage.
Not the ones we have built. We have used dedicated power blocks with no regulators. This was actually a mandatory requirement, but I certainly agree with it.
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Old 10-23-2019, 01:46 AM
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Quote:
Originally Posted by wyo69cowboy View Post
Would a 3S lipo regulated system be a good way to go, if you're worried about keeping voltage constant to the servos?
Personally, I would say absolutely no. Whenever you have regulation required you are going to have severe drop outs under load, unless you are using caps the size of what is used Pro Audio class car stereo competitions - which are huge and weigh pounds.

Servo manufacturers that make HV (high voltage) servos are designed to use "7.4v" Lipo systems. This means 7.4v is the minimum voltage, not the maximum. Any voltage above this does not increase the speed of the servo because the computer in the servo regulates the PWM output to the motor to maintain the same speed between the 7.4v and 8.4v range. This is why Lipo setups do not need any type of regulation to have the same speed. There is plenty enough current with a Lipo to mitigate dropouts, with most of that actually being caused by the wiring itself being too small for the amount of current being used.

Likewise, the discharge curve of a LiFe like a A123 is extremely shallow, holding it's nominal voltage (6.6v) for about 95% of the discharge cycle. Because of this, you also do not need regulation to maintain the same servo speed through out the discharge cycle of the battery.

You can ALWAYS provide more current with a non-regulated power system. Adding regulation doesn't help maintain a servo's speed when using LiFe or Lipo batteries. Adding regulation doesn't prevent drop-outs, it actually creates them. Adding regulation just adds extra weight and gives you one more point of failure, with absolutely no advantages.
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Old 10-23-2019, 01:49 AM
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Originally Posted by XPS View Post
Not the ones we have built. We have used dedicated power blocks with no regulators. This was actually a mandatory requirement, but I certainly agree with it.
so XPS builds UAV's?
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Old 10-23-2019, 01:57 AM
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What? Lower? OK!
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Ahh, an old story again ... It's more about finding reasons why one wants to justify that his commercial device has no oring circuit nor regulator, nothing more nothing less, sorry ...


And this statement ...


Any voltage above this does not increase the speed of the servo because the computer in the servo regulates the PWM output to the motor to maintain the same speed between the 7.4v and 8.4v range.


... will not be true for all servos.
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Old 10-23-2019, 01:59 AM
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Quote:
Originally Posted by wyo69cowboy View Post
Anyway, still curious what happens with a BEC or other voltage regulator when the input voltage falls below the set point.
That depends on the design of the regulator. Even with high-end switching regulators can have a tiny bit of drop out. The smarter designs actually boost the output voltage to eliminate the drop-out, but this requires more current to provide this... and a lot of board space and parts. They are also typically very noisy compared to linear regulators.

Common linear regulators, often referred to as "LDO regs" are Low Drop Out regulators that are not switching. There is a drop-out specification, which means that there is a minimum voltage required in addition to the desired output voltage. A good example of this is our X24. The ignition BEC is a linear regulator that has a full load drop-out voltage of about 0.5 volts. This means that if you have the X24 set to output 6.0v for your ignition voltage you will need to have at least a 6.5v input voltage in order for it to supply 3A continuous. Less amperage means less of a drop-out. So, what happens when that voltage is only 5.0 volts? Well, again that depends on the design. Some LDO regs will starts oscillating when the voltage drops below the min spec. The X24's BEC is flat until min spec. This means that the BEC will output the input voltage (minus 0.5v) all the way down to about 2.9v before the regulator shuts itself off. There are no harmonics at any voltage. I prefer this to lower voltage operation and wild voltage swings.
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