I have talked with Dave for some years about his simple redundant power supply. It always works & he tests it before and after each flight. A good practice! I too will be using his RPS in my larger, more expensive aircraft. Thanks for the great video. I finally got around to watching. Well done.
After "roasting" a castle cremation ESC on a beautiful new (expensive) airplane with catastrophic results, (about 12 total minutes of flight time over three flights) I am convinced some inexpensive redundancy is the answer. Thanks guys! Best I could tell, the reason for the roasting, was having the breaking system turned on. I didn't realize it would be that much of a strain on the ESC. But I'm thinking that must've been it. Because pulsing the throttle on the low end was causing it to start AND stop the prop. I realize now that that is hard on the ESC.
Looks like the set up I can use on my 1/4 scale gassers. Two 2S 2500 LiFe A123 batteries in parallel with each having this Schottky diode in their positive lead. Then I can run that single power source to the receiver, ignition module and lighting. Originally I was going to have 3 separate batteries for isolation. But with this set up, if a battery fails it would still be flyable and telemetry can probably be set up with a warning. And when working I'll have the current of both batteries for the three systems.
You are welcome the two scenarios I talked about if you all want to and John wants to we may make a video to show exactly what it is very simple very safe very cheap
Excellent video, I was planing to setup a parallel power source for my planes and was concerned about the back-feed issue. The diodes are the solution…thanks!
Very interesting video. Presumably you don't actually use such a large/heavy backup battery in a real world set up but just the min weight battery pack needed to give backup. Otherwise there's a significant extra weight and space needed issue. Also, for those of us whose understanding of electronics is limited to being able to solder, can you advise where we buy that diode and what spec to be looking for. Also the common rail connector. Looking quickly through the links with the video I couldn't identify those (though I may well have just missed them!). Would welcome advice on all of this & thanks.
My RC yacht lost comms about 100 meters offshore (lake) due to low power from the single battery onboard and started drifting further away with the wind. Luckily a power boat was passing by and retrieved it. Fix: Implement this super simple Redundant Power System and sail with an onshore wind.
If you all would like and John wants to do it we can probably make a short video and show you in real life on my airplanes what I do and why which would actually be a second and third options to what John showed on the video I've been using these methods for 10 years without a problem on very expensive airplanes for my pocket
i just added 5v aux power to my EDF BAEHAWK with matek f405 with a 5v bec plugged into a power distro rail, then plugged servos into that and that into the 5v servo outputs from the board. this doubled my available amperage for servos. i am running 9 servos on 9amps. should be plenty to prevent brownouts in case a servo seizes up.
Yeah that will do it if both the voltage sources are the same. This is exactly like a parallel battery setup. Same volts double the amps. Good job. Thanks for sharing your setup tip with the channel!
So therefore the BEC that supplies the highest output will always be the source to the receiver, am I right? If the redundant source BEC happens to have a higher output (even by 0.1v) you're effectively increasing your capacity overall I guess, and you would land with voltage drop in both batteries; Esc supplying motor, BEC supplying rx.
Great. Is it possible to have an indicator that one supply has failed? Also seems the secondary battery does not seem to need high amp hour as it would only run receiver. Main battery is getting juice sucked out by motor?
Hey guys just a quick tip to all of you that want to do this system when you get your diodes test the diode with a meter and with a battery to make sure there is no reverse voltage I have gotten them before with reverse voltage leakage you don't want that
I have two different scenarios we're I use this 1 opto speed controllers I do not use a regulator I use a 2cell life battery with a diode in series to drop the voltage to a safer leve for servos rated up to 6 vote part of a redundant system which is two batteries two diodes with two switches to the receiver those two would be the same voltage they would drain at the same time the other thing I do is used one battery which is the life battery with a diode to drop the voltage a little bit make it safer for my servos and the other one comes from the speed control with the diode so we are not feeding any current back yes one of them is higher you will use voltage out of the higher one but if any of them fail you'll have the other one as a backup. The diodes also prevent voltage from feeding backwards either into the speed control or into the life battery or LiPo battery you do not want neither one of these scenarios to happen
So when two voltage sources with different voltages are connected the higher voltage source provides the current. When two voltage sources with similar voltages are connected they both provide current. That's how it works with parallel batteries anyway--they both come back empty after a flight.
I agree with your system and have a theoretical question. If a model was to be equipped with a receiver pack and was space/weight limited on that pack could the bec circuit step in to cover the sag in an Rx pack that is to small? My jet has 2 5a bec on board making for roughly 10a of capable servo drive power. The 11 servos it carries can stall load .9a per servo. Uncomfortably close to the max output of the bec. Can I put an Rx pack in the system, all be it to small and only good for 12a, then install a Schottky diode on the bec output so the bec only gets loaded when the Rx pack saggs below say 7.8v? Then have the possible 12a from the Rx pack and the potential of the bec at 10a combine to give me the overhead I'm looking for?
"Schottky diode on the bec output so the bec only gets loaded" If you have two different voltage sources with two different voltage levels, the higher will always feed the lower. In the example, the diode is used to prevent this. So the higher voltage source always feeds the load, but cannot get past the diode to the other lower voltage source.
@@RCVideoReviews so the switching power supply will still be providing power to the circuit even though it's target voltage is above the set point? I guess I figured with a Schottky on line the bec wouldnt be doing much of anything until the voltage drops on the other side. Am I going to simple on my thought process?
Very simple idea, but I have a question: which one of the batteries takes over as a main? Since both are connected, are both providing power to the system? Thanks .
I don't understand your question. The point behind this is to provide redundant power. Putting a single bec between the battery and load doesn't really accomplish that. So I'm not sure what you're driving at. To put a short answer to this: The purpose of the diode is to prevent higher electrical potential from pushing voltage to alternate devices. With that premise in mind, you can arrange your source/load how you wish.
If your left battery dead your receiver still got power from the right battery. But your plane still crash because the motor only got power from your left battery through the esc.
Like inline with the battery? I've never used one. I just plug it in or unplug it. There are switches you can buy to go inline with the BEC from either your ESC or standalone.
Good explanation here: www.eevblog.com/forum/projects/how-do-i-choose-the-correct-schottky-diode-for-a-project/ Bottom line it needs to be able to handle the voltage/current you plan on throwing at it with acceptable forward voltage drop (to you).
@@RCVideoReviews thanks for replying so quickly I'm very much a noob to this having bought some electric powered models the motor is an 800 size and it has bec of 5.5v 5a 2-6 s with a 3a 5a max ubec mounted on its back
NOPE ...you did not steal it. you had peremission from the original creator. HEE HEE ... Liteally right now I am exploring the Open Source Hardware License funda. Credit where its due. CHEERS
![АЛАУДИНОВ у Скабеевой: эти их ВСУ нас НЕ ДОГОНЯТ 😁 [Пародия]](http://i.ytimg.com/vi/an0anqU4WGQ/mqdefault.jpg)
I have talked with Dave for some years about his simple redundant power supply. It always works & he tests it before and after each flight. A good practice! I too will be using his RPS in my larger, more expensive aircraft. Thanks for the great video. I finally got around to watching. Well done.
Yeah, this is a brain dead simple method to add redundancy. So glad Dave shared it with the channel.
@RCVideoReviews This Blue BEC in your video is commercial or build buy you? I was thinking in build some specifics BEC for my planes and robots.
After "roasting" a castle cremation ESC on a beautiful new (expensive) airplane with catastrophic results, (about 12 total minutes of flight time over three flights) I am convinced some inexpensive redundancy is the answer. Thanks guys!
Best I could tell, the reason for the roasting, was having the breaking system turned on. I didn't realize it would be that much of a strain on the ESC. But I'm thinking that must've been it. Because pulsing the throttle on the low end was causing it to start AND stop the prop. I realize now that that is hard on the ESC.
I know I have talked to u about this before. This video is so clear that even "brain dead" me could understand. Thanx.
Thanks John. Hopefully you can put this info to good use.
Always been interested in this for use in some medium to long range builds. Glad i stumbled upon this. Great explanation
Glad to help.
Looks like the set up I can use on my 1/4 scale gassers. Two 2S 2500 LiFe A123 batteries in parallel with each having this Schottky diode in their positive lead. Then I can run that single power source to the receiver, ignition module and lighting. Originally I was going to have 3 separate batteries for isolation. But with this set up, if a battery fails it would still be flyable and telemetry can probably be set up with a warning. And when working I'll have the current of both batteries for the three systems.
10 of those diodes are $3.98 plus shipping. I will be using this in the future when I start trying long range FPV. Thank You, DAVE!!! You Da Man!
You are welcome the two scenarios I talked about if you all want to and John wants to we may make a video to show exactly what it is very simple very safe very cheap
This solution is so cheap and light you can use it on any nice plane. It's such a minor effort to add this backup.
Excellent video, I was planing to setup a parallel power source for my planes and was concerned about the back-feed issue. The diodes are the solution…thanks!
You are welcome!
My new fav channel
Glad to have you. Hope to see you participate regularly.
Good idea but be sure to use strong enough diodes. I'm not sure how much current the servos can pull, obviously varies depending on the plane.
Very interesting video. Presumably you don't actually use such a large/heavy backup battery in a real world set up but just the min weight battery pack needed to give backup. Otherwise there's a significant extra weight and space needed issue. Also, for those of us whose understanding of electronics is limited to being able to solder, can you advise where we buy that diode and what spec to be looking for. Also the common rail connector. Looking quickly through the links with the video I couldn't identify those (though I may well have just missed them!). Would welcome advice on all of this & thanks.
My RC yacht lost comms about 100 meters offshore (lake) due to low power from the single battery onboard and started drifting further away with the wind. Luckily a power boat was passing by and retrieved it. Fix: Implement this super simple Redundant Power System and sail with an onshore wind.
If you all would like and John wants to do it we can probably make a short video and show you in real life on my airplanes what I do and why which would actually be a second and third options to what John showed on the video I've been using these methods for 10 years without a problem on very expensive airplanes for my pocket
We can do a video on this next time we're at the field. I think it would be good to show how you've implemented it in practice.
Absolutely yes we can
Thank you
You're welcome
i just added 5v aux power to my EDF BAEHAWK with matek f405 with a 5v bec plugged into a power distro rail, then plugged servos into that and that into the 5v servo outputs from the board. this doubled my available amperage for servos. i am running 9 servos on 9amps. should be plenty to prevent brownouts in case a servo seizes up.
Yeah that will do it if both the voltage sources are the same. This is exactly like a parallel battery setup. Same volts double the amps.
Good job. Thanks for sharing your setup tip with the channel!
So therefore the BEC that supplies the highest output will always be the source to the receiver, am I right? If the redundant source BEC happens to have a higher output (even by 0.1v) you're effectively increasing your capacity overall I guess, and you would land with voltage drop in both batteries; Esc supplying motor, BEC supplying rx.
Great video as always.
Thank you.
Great. Is it possible to have an indicator that one supply has failed? Also seems the secondary battery does not seem to need high amp hour as it would only run receiver. Main battery is getting juice sucked out by motor?
Is it possible? Yes, sure it is. I suppose if you knew it failed over, a smaller battery could be used. Lots of options here.
👍
Hey guys just a quick tip to all of you that want to do this system when you get your diodes test the diode with a meter and with a battery to make sure there is no reverse voltage I have gotten them before with reverse voltage leakage you don't want that
It's also a good idea to verify forward voltage drop. That's the reason for the Shottky diode by the way--minimal drop compared to standard diodes.
All receiver are able to receiver two input power? I always thinking the receivers are only be able to have one input voltage in one channel pins
I have two different scenarios we're I use this 1 opto speed controllers I do not use a regulator I use a 2cell life battery with a diode in series to drop the voltage to a safer leve for servos rated up to 6 vote part of a redundant system which is two batteries two diodes with two switches to the receiver those two would be the same voltage they would drain at the same time the other thing I do is used one battery which is the life battery with a diode to drop the voltage a little bit make it safer for my servos and the other one comes from the speed control with the diode so we are not feeding any current back yes one of them is higher you will use voltage out of the higher one but if any of them fail you'll have the other one as a backup. The diodes also prevent voltage from feeding backwards either into the speed control or into the life battery or LiPo battery you do not want neither one of these scenarios to happen
So when two voltage sources with different voltages are connected the higher voltage source provides the current. When two voltage sources with similar voltages are connected they both provide current. That's how it works with parallel batteries anyway--they both come back empty after a flight.
I agree with your system and have a theoretical question. If a model was to be equipped with a receiver pack and was space/weight limited on that pack could the bec circuit step in to cover the sag in an Rx pack that is to small? My jet has 2 5a bec on board making for roughly 10a of capable servo drive power. The 11 servos it carries can stall load .9a per servo. Uncomfortably close to the max output of the bec. Can I put an Rx pack in the system, all be it to small and only good for 12a, then install a Schottky diode on the bec output so the bec only gets loaded when the Rx pack saggs below say 7.8v? Then have the possible 12a from the Rx pack and the potential of the bec at 10a combine to give me the overhead I'm looking for?
"Schottky diode on the bec output so the bec only gets loaded"
If you have two different voltage sources with two different voltage levels, the higher will always feed the lower. In the example, the diode is used to prevent this. So the higher voltage source always feeds the load, but cannot get past the diode to the other lower voltage source.
@@RCVideoReviews so the switching power supply will still be providing power to the circuit even though it's target voltage is above the set point? I guess I figured with a Schottky on line the bec wouldnt be doing much of anything until the voltage drops on the other side. Am I going to simple on my thought process?
Can you please show me a link where I can purchase some of these diode's thank you very much
amzn.to/44nfqn4
Just wondering where can we buy the exact diode you are using. I found 45v/15a diodes, but not 35 v/9a. Great video and good content. Thank you!
It's in the video @8:01
When you get your diodes make sure you test them to make sure there's no reverse voltage some of them have reverse voltage
Just looked at DigiKey and couldn't match the part number you provided. Is there a current alternate part number you can provide, Dave? Thx!
Just heard back from DigiKey. The new part number is 1655-90SQ035CT-ND.
Very simple idea, but I have a question: which one of the batteries takes over as a main? Since both are connected, are both providing power to the system? Thanks .
The one with higher voltage is becomes the source.
@@RCVideoReviews Thanks for posting this, I used this method for my RC plane and works really well, no issues, wow.
With this diode arrangement if your ESC output 8V and your BEC 5v, which voltage that the RX will get?
Higher voltage potential feeds lower potential whether it's 5v or 0v.
Can you do the same with the same battery source, an external BEC, and a couple of XT60s?
I don't understand your question. The point behind this is to provide redundant power. Putting a single bec between the battery and load doesn't really accomplish that. So I'm not sure what you're driving at. To put a short answer to this: The purpose of the diode is to prevent higher electrical potential from pushing voltage to alternate devices. With that premise in mind, you can arrange your source/load how you wish.
If your left battery dead your receiver still got power from the right battery.
But your plane still crash because the motor only got power from your left battery through the esc.
It’s not intended to keep the motor running. It’s intended to keep power to your receiver so you can land the plane.
That fact is explained here: ua-cam.com/video/yowcjweWkaQ/v-deo.html
Do u happened to know if there's any reliable on/off switch for lipo?
Like inline with the battery? I've never used one. I just plug it in or unplug it. There are switches you can buy to go inline with the BEC from either your ESC or standalone.
Do you think a 15A 45v schottky diodes will work?
Sure, that has more capacity than the ones I used in the video so they should work fine as long as you don't exceed those specs on your circuit.
Hi buddy what size diodes would I need for this many thanks ray
Good explanation here: www.eevblog.com/forum/projects/how-do-i-choose-the-correct-schottky-diode-for-a-project/
Bottom line it needs to be able to handle the voltage/current you plan on throwing at it with acceptable forward voltage drop (to you).
@@RCVideoReviews thanks for replying so quickly I'm very much a noob to this having bought some electric powered models the motor is an 800 size and it has bec of 5.5v 5a 2-6 s with a 3a 5a max ubec mounted on its back
NOPE ...you did not steal it.
you had peremission from the original creator.
HEE HEE ... Liteally right now I am exploring the Open Source Hardware License funda.
Credit where its due. CHEERS