Tech-Aero Regulators
 

Does anyone know the difference in weight between the Tech-Aero PLR5 and the PLR5-DR2? I'm debating on switching to redundant power if Ihave enough room for weight.

Thanks,
Scott

RE: Tech-Aero Regulators
 

Scott,

It is less than 1 oz. The only thing doubled is the regulator. It uses the same switch harness and such.

Arch

RE: Tech-Aero Regulators
 

Thanks Arch.  I have enough room for the 1 oz and an extra battery.  I think this is the way to go.

Thanks man

RE: Tech-Aero Regulators
 

I use 2 PLR5-e's. Can appreciate having a switch on the battery power if you want, but since current draw is next to nothing when plane is idle, not much loss while you (un) secure canopy.

Lightest way to get redundant power and reduces failure points.

RE: Tech-Aero Regulators
 

Thanks Joe.  That's an EXCELLENT idea.  I'll use two PLR-5e in my backup (since the switch is mounted on the inside) and the DR2 for the primary (switch already on the outside).  Don't want a hole in the side of my bird ;)

Scott

RE: Tech-Aero Regulators
 

So, with the PLR-5e, do you disconnect the battery from the receiver after every flight, since there is no switch?

RE: Tech-Aero Regulators
 

What individual battery capacity are you guys using with the redundant setup?

RE: Tech-Aero Regulators
 

.
I'm using a 2S-350 LiPo for my backup battery, and drawing 2 cells off my 10S-5000 LiPo motor battery thru the balance plug for the main radio power.
.
No switches, just plug everything in each flight since I'm taking the canopy off to plug in the batts anyway . . . two less components to fail or carry around.
.
My planes lost 44 grams going to this setup vs. carrying a separate receiver battery and one power source.
.

RE: Tech-Aero Regulators
 

I am running the same setup at Keith and are seeing virtually identical numbers. Definitely worth another 1 1/2 oz for the redundancy,

Arch

RE: Tech-Aero Regulators
 

I use two 450mah packs with two independent PLR5e regulators. I plug/unplug my Rx batteries before/after each flight when I plug in my power packs.

This setup came as a recommendation from Ed at Tech-Aero for the lightest possible setup (using 2 rx batteries).

I don't think I use half the capacity of my Rx batteries in a weekend of flying.

RE: Tech-Aero Regulators
 

I too use the Tech-Aero set up with two 360 Rhinos. It occured to me that I might just draw from the two flight batts via the balance taps tapping into 2 cells thus eliminating the Rhinos, their weight and charging. Why not?

Pros and cons please....

Thanks,

RC

RE: Tech-Aero Regulators
 

.
http://nsrca.us/forum/index.php?topic=167.0
.
I have well over 100 flights between two airplanes. Works great. Imagine never charging a receiver battery again (only your backup once a month) . . .
.
Just don't try to run two regulators off the same motor pack, they will have a common ground and the magic smoke will escape. You want a completely separate backup system, both electrically and physically. . .
.

RE: Tech-Aero Regulators
 

Thanks Keith for the pointer. I suspected using only the motor batteries amounted to having a single-point-of-failure condition - but I had not thought about the "battery ejection" scenario! And the "common ground" issue did not resonate either. I really like the idea of having a small mah 2s to backup a 2-cell tap off the motor batteries. And thanks Arch for providing a 2nd opinion vote of confidence for this method!

RE: Tech-Aero Regulators
 

What is wrong with a common ground? Seems like you have a common ground as soon as you connect each regulator to the receiver.

Jim

RE: Tech-Aero Regulators
 

.
My original thought was to plug one regulator into one 5S pack (tapping off two cells), and the other regulator into the other 5S pack (tapping two cells off that pack as well) for redundancy.
.
The problem is that with the two 5S packs connected in series to run the motor, the regulator's ground wires are now at different voltages from the motor battery packs. Say that you tap off cells 1&2 for the first regulator then 6&7 (first two cells of the second 5S pack) for the other regulator. You now have a 5S voltage differential (21 volts) between the two regulators ground wires that are now connected at your receiver's power bus. The negative side of the regulators aren't isolated, they're straight thru, so something has to give.
.
Hope my explanation makes sense. . . If you read down the NSRCA thread, John Gayer already did the te$ting for us . . . .
.

RE: Tech-Aero Regulators
 

Very clear. I could have told you that wouldn't work.

I'm not wild about using the bottom two cells of the motor battery. The ESC designers went to a lot of trouble to optically isolate the high voltage section from the receiver. There is high current flowing in those two cells and it has what electronics guys call an AC component when it is at throttle positions less than 100%. Since current to the regulator is flowing in this same circuit the AC gets coupled into the input of the regulator. If the regulator filters this before it gets to the output and into the receiver you are okay but I'd be careful. I'll try to build one up and see what I can see.

Jim

RE: Tech-Aero Regulators
 

Idon't really recommend this 5S / 2S configuration, but I have explained to some how it can be done. The output from the regulators is clean enough, no big concerns about AC components and what not, but if you don't wire this exactly right, you can smoke your receiver, regulators, wiring etc. If you know exactly what you're doing, fine. Otherwise, use a 2nd little LiPo please as gaRCfield is doing.

RE: Tech-Aero Regulators
 

Just bought the PLR5-1. I like be able to shut the airplane off via a switch. I will be running 2 of these for redundancy in my new plane. Did not need the charge lead since I charge my batteries through the balance tabs. Was thinking about the power box digi switch, but after talking to Ed, I was sold on Aero-tech. Keep up the good work Ed

RE: Tech-Aero Regulators
 

.
I just told the regulator that's connected to the motor battery to "not let any nasty AC components pass ". . .
.

RE: Tech-Aero Regulators
 

The common ground I was refering to is a common ground between the receiver side and the battery side in the ESC. In the fully isolated CC ICEHV 80, there is no connection between the receiver and battery sides of the ESC for either power or ground. This allows you to take any two cells from your 10s pack and feed them to a regulator and use a second regulator driven by a small lipo for backup set to a lower voltage.
If you have a ESC without that ground isolation , such as a CC ICE 100 with a BEC, then using the motor battery is possible but you must use the lowest two cells in the overall pack(8-10S) This is not a very good idea when you have two balance connectors and other ways to screw up.
Also,there is no good way to use two regulators on the same motor battery without making smoke nor should you want to do that. How many motor batteries have you seen ejected? Happened at the Nats this year.
Another thing- you cannot parallel switching regulators such as the SmartFly this way unless you run a BattShare. Of course that puts you back to a single point of failure. Stick to Jim or Ed's regulators.

Has anyone checked the ripple voltage at the balance plug and at the regulator output? I haven't noticed any issues and my servos have no buzz. I have over 200 flights on a system using a CC HVICE 80, a 350 2S lipo, 2 tech-Aero regulators with separate switches and a connection to the motor battery for the second regulator on the lowest two cells of a balance connector. I feel the two separate switches are very important. I check both lanes for independant operation before each flight. That is difficult to do with a single switch or plugging in connectors. The 350 Lipo will last for weeks without dropping off enough to recharge.

John

RE: Tech-Aero Regulators
 

So what voltage is your 2S lipo maintaining all this time?

RE: Tech-Aero Regulators
 

.
If you set your "backup" regulator to a lower output voltage than your main regulator, the 2S LiPo is just along for the ride . . . sittin' there at idle waiting to be a hero.
.
I set my main regulator output to 5.9V, and the backup to 5.7V. The 2S-350 is still at 100% after a full day's flying.
.

RE: Tech-Aero Regulators
 

About the same as Keith. I'm using 6.0 on main regulator and 5.8 on the backup lipo regulator

RE: Tech-Aero Regulators
 

I personally run both of mine at the same voltage. I don't see the point in just carrying one for the ride. Mine draw equally from both, and the regs are so accurate, I've yet to put more than 10mah more back in one of the packs versus the other.

Arch

RE: Tech-Aero Regulators
 

Arch,
I agree with your philosophy when using two small lipos as you do. You want equal discharge from both to maximize your remaining battery capacity if one were to fail.
Keith and I operate under the same idea but one of our batteries is effectively infinite so we draw power from the motor battery to keep the small backup lipo as charged as possible.
John

RE: Tech-Aero Regulators
 

Any pics of your set up Keith?

RE: Tech-Aero Regulators
 

As an update, I decided to go with two PLR5 failsafe switch w/ regulator.  The reason is I just don't like the idea of unplugging my RX connection to the lipo every time I take my canopy off.  I do not draw power from the motor's 10S pack and keep them totally separate.  Yes, it added 50g to my airplane but I'm still at 4850g RTF so the weight wasn't a concern.  I do like the ability to check each regulator with the failsafe switch just by turning each one on individually and then both on for the flight.  For me, this made the most sense.  This check is very similar to checking the magnetos in a Cessna...switch to each one to make sure they are functioning and back to both for the flight.

Thanks for everyone's input,
Scott

RE: Tech-Aero Regulators
 

I just tested the set up and it seems to work fine. I did measure about 0.4 volts peak to peak at the input to the Jaccio regulator but the output was clean as I expected it would be. A few years ago I worked with a company that was flying a big helicopter with a TV camera/transmitter on board. The RC system was using the same battery pack as the TV system and every time a servo drew current they could see it on the video. We put a regulator between the battery and the TV system and it filtered out the ripple on the input and solved the problem.

I had been thinking about a redundant power system and this looks like an easy way to do it. While I'm at it I will put a voltmeter on the connection to the bottom two cells that will tell me when I plug it in that the pack is charged (or not). You never want to take off with a pack that isn't charged.

RE: Tech-Aero Regulators
 

Hello Jim,
Is that ripple at commutation rate or at the chopping rate? Sorry I couldn't read the timebase.
400 mV on two cells! I guess it's not that surprising. So that works out to maybe 2V peak to peak across the entire pack.
Sounds like more filtering at the ESC would lessen the current peaks at the battery. I wonder if the batteries will respond well to that.

Regards,
Dean Pappas

RE: Tech-Aero Regulators
 

The timebase was .2 msec per division so it looks like it is the 8KHz PWM frequency. I never went to full throttle but I would assume the ripple would disappear at 100% duty cycle as you would get a fairly pure DC at that point. I don't know what the effective series resistance is across the two cells but the 400 millivolts seems reasonable if the R was 10 milliohms and the I was 40 Amps.

We need the regulator to get down to 6 volts and it does the filtering so I don't see a need to do anything else at the battery/ ESC interface.

What have you been up to? What ever happened to electric control line? I can't keep up with all the stuff that is going on but I find a lot of folks getting ahead of the pattern guys when it comes to new technology.

Regards, Jim

RE: Tech-Aero Regulators
 

Hi Jim,
So it's the chopping rate that we see. Okay, that's high enough to easily filter out of the regulator output, and low enough not to cause any RF issues, seeing how the RX ground is going to end up riding on top of a common mode noise signal at the same frequency.
I wonder if there is any real high frequency crap as well? I can't imagine that the big electrolytic caps we see on any firm's ESCs are any use at RF. I would imagine that 2.4G is completely unaffected, but 72 Meg just might get unhappy.

E-Stunt? Let me see if I can sum it up in just a few words. It's GREAT! There are a fair number of holy-war, "don't change my event" naysayers, but it works better than even the best piped two-strokes and four-stroke setups.

1)We are running with the ESC set in helicopter RPM governor mode, and if you have the gain adjusted high enough and the RPM control loop response speed set fast enough (just a safe margin of stability, but noticeably underdamped) then ...
2)The vertical uphill RPM is only 100 RPM or so below that of level flight and,
3)vertical dive RPM is maybe 100 or so above level flight.
( for comparison, excellently set up four-strokes and piped two-strokes exhibit about 1000 RPM differences from climb to dive and the classic muffled 2-4 Stunt run shows close to 2000 RPM difference)
4) There are experimenters looking to make the system recognize where the plane is on the circle so as to compensate for the few hundred RPM variations we still see, but this is still far from ready for prime time.
5) Podium places at Worlds have been taken with electric, and this year's European Continental Championship has been won with Electric.

Now for the cross-pollination part of our discussion ... The constant RPM setup surely will work for Pattern: it will turn the throttle into an "airspeed setting lever".
The only problem is that this only works if you have enough overhead to achieve the governed RPM at the slowest speed needed while in a vertical climb.
As a data point, static current at the set RPM is about 135% of the cruise flight current at the same RPM.
I strongly suspect that the very long vertical downlines we fly, and the lack of control-line-drag will require an RPM governor that engages the regenerative brakes.

In my opinion, this approach will get close to the point where sensored motors will be needed for the frequent changes from driving to braking at high energy levels.
We already see that ESCs have issues with the transition from braking to running hard at low RPM. Sensors will fix that.

take care,
Dean P.

RE: Tech-Aero Regulators
 

Thanks for the report Dean,

Not sure I understand "...static current at the set RPM is about 135%..". Does that mean the current at zero velocity?

I believe we have the overhead required as I have done the Masters pattern never exceeding 2500 Watts and our batteries are getting better. However, I'm sure there will be conditions where we might need more power but we don't need perfect regulation. I agree the sensors might be the answer to the control problem. It looks like Futaba uses them in their brushless servos. I've also heard rumors they might have an RPM controlled power system coming.

Stay tuned, things just keep getting better, Jim

RE: Tech-Aero Regulators
 

Jim and Dean,
Seems like the right participants are here for me to ask a question.

It appears that we all would be be better off if the throttle stick operated as an RPM request.  This would eliminate or greatly reduce any problems with reduced power availability later in the flight as the batteries discharge. We could all get used to a given stick position being a given RPM(power for a given set of conditions). The batteries these days typically have excessive power available at the beginning of the flight.

I don't see why any additional hardware or sensors would be required to do this. The RPM is currently reported in the CC ICE as an output plot so it is clearly available in the controller software. All that would be required in the software is a simple control loop based on throttle stick input and RPM feedback. Possibly more processing power would be required but the code is simple enough.   It would be best if you could set min RPM and max RPM as parameters input through the data link. Any deviation from a straight line between the two RPM end-points could be handled in the transmitter.

What am I missing here? Why isn't this available to me and at a reasonable premium? I am fairly new to electric,at least for pattern and this appears to me to be the only substantial disadvantage of electrics compared to the YS.

John Gayer

RE: Tech-Aero Regulators
 

Hi John,

I'm no control system or servo designer but I do know the dynamics are quite complicated. Controlling the RPM at a given value is not the problem, it is the requirement to change the desired RPM quickly as we move the stick quickly. Measuring the RPM cannot be done quickly. What you read out is an average of some number of cycles over time. To have the desired frequency response you'd need to measure angular velocity many times per revolution. Then with the high inertia you'd need lots of change in torque in both directions to control the angular velocity.

Having said all this, I'm sure it will be done eventually. Right now I still feel the advantages of the electric system far outweigh the change in "throttle feel" from the beginning until the end of a flight. The guys that practice can control the speed as well as the path of the aircraft. I'm still working on the path as well as he speed.

Jim

RE: Tech-Aero Regulators
 

Wouldn't a 35V regulator on the power batteries give constant throttle feel? Isn't that why we use regulators on the Rx battery in the first place (consistent control feel)?

I'm learning this as I've been working on understanding my power setup and looking at the graphs. Thought I was dropping down in power, really I was running a conservative setup and staying in the 'fresh zone' for a longer period of time. Throttle feel is pretty consistent once the battery voltage drops down and levels off - the whole point of using lipos is for that 'voltage plane' which levels out for quite some time.

Not that I think I would bother using a regulator, at least at this point - really just need to learn to slow down my trim pass and fly at constant speed from there.

RE: Tech-Aero Regulators
 

The ESC IS a regulator that is regulating voltage to the motor rather than regulating RPM, as a function of stick position. You would never want to put two regulators in series.

Yes we do use a regulator to keep the servo voltage and speed consistent as the battery voltage drops during flight and from flight to flight. It shouldn't be required in Futaba's new programmable brushless servos where you can program speed. I will try to run some tests and let you know if this is true.

Jim

RE: Tech-Aero Regulators
 

Sounds like the ESC could do a better regulating job by taking into consideration the voltage: higher voltage - shorter power pulses; lower voltage - longer power pulses.

I can definitely feel more power when the pack is fresh (close to 42v) with CC HV 85. With CC ICE HV 80, the extra "power surge" is less evident.

RE: Tech-Aero Regulators
 

Jim,
I see your point about how long it would take to determine the RPM to a reasonable accuracy. It would depend on the frame rate used in the processor but it is certain to be a substantial number of frames.
Having this capability cannot be too far off if Dean can control to a static RPM within +/- 100 RPM for controlline. Sounds like everything is in place except the response time of the RPM delta,
John

RE: Tech-Aero Regulators
 

Hi All,
Jim, yes zero-airspeed is what I meant by static conditions, and you're right about needing to evaluate the available overhead.
Oh yes, and you're too darned modest.

As far as RPM governed operation goes, I can easily say it will lessen the pilot's workload, but I already think airspeed control is easier with E-Power.
When well optimized, the exponential response time to a step change in load is about 1/4 second. This is the case with the Castle Phoenixes, at least.
The CL setups use no braking except for a hard brake at motor shutdown. Our planes are cleaner and heavier and lacking control-line drag we need the brakes going downhill.

Like I said, the high energy transition from pulling to regenerative braking and back to pulling, while the RPM is commanded to maybe 5500 is more than any of the ESCs out there are capable of.

I think there is a way around the problem, so that E throttle management is less of a handful.

later,
Dean

RE: Tech-Aero Regulators
 

HI guys,
   I went out and tested my new setup with the two Tech-Aero regulators and separate packs yesterday.  I flew several flights and when I got back home, I pulled the packs out to check voltage.  The pack that has always been there with a single regulator read the same as it usually does after 3 flights and the backup pack seemed to almost be at a full charge.  I check to make sure each pack is powering the receiver as described before by turning on each switch separately and then both on for flight.
  Maybe I had the wrong idea about this so I'm just trying to confirm.  How does this actually work?  Does the rx draw off the main pack that's plugged into the "Battery" slot on the RX and discard the pack that's plugged into a spare channel or does it draw off of both at the same time equally?  I would think if it was equal and assuming both packs started out at the same voltage, they would at least be close to each other.  The "primary pack" seems like it got used a lot more than the other.  How does this actually work for the RX?

Thanks,