Questions about voltage boosters and power supply

Thread Starter

Stillers48

Joined Jul 12, 2020
21
FIrst off, Ill post my disclaimer: I am as green as the spring grass when it comes to all things electronics other than how to use them, I have a general understanding of the concept, design, and operation of them . That is it. But Ive never been afraid in the slightest to sail off right into the middle of things know nothing about and throw a hand at it. After all, thats the first step to becoming well versed in a subject, right? The difference is that most people take that first step into a class room, or into some other form of instructor-led environment. When I do it I usually try to walk off the street and sit in the CEO's chair, Learning off of self education and peer-to-peer consult. I decided to take one a from scratch build project for my son and assemble a much more comprehensive and customizable Led light power and control system for my sons drone. Hes autistic and LOVES light shows and the market for Custom drone lighting is......... Lacking. Its vastly underserved and low tech. Necessity is the mother of invention. So here I am, building my own overpowered, underengineered, barebones bush league light system that will probably be on the verge of exploding at any second and i intend to strap it to a drone and fly it 200 feet over peoples heads. People as immature as me should never be as smart as i am. This is what you end up with; At any rate, my questions are in regards to the light power systems. This is the second design attempt; The first one was grossly inept and underpowered and along with that as well as some other complications had to be canned. This new design is much more complex, but also has serious dimensional restrictions. Spatial limitations on this buils is 60mm x 140mm x 30+/-5mm. 139mm x 59mm x 8mm of that is already gone to accommodate the batteries. take off another 5mm in height because of multiple circuit board layers. Its powered by 2 3.7V 5000mAh Lithium Polymer batteries. Current design is to wire them in series, but thats also part of the reason Im here. Instead of the UBECs in V1 that regulated power, V2 calls for using a DC Boost Converter Module for power management. The different components planned to be implemented in the system will have operating voltages of 5V and a few will be 12V, including a RF Relay Switch. Also planning to mount an onboard charge/discharge protection BMS board on the back end. My question is about which Boost Converter is best for my application. I havent scaled it out 100% but preliminary data is suggesting that I will not have the space for a Buck-Boost Power Supply like this DROK model shown here:

https://www.amazon.com/dp/B078Q1624B/ref=cm_sw_r_other_apa_i_3W8fFbPHWJY39

The most likely choices will be a device simlilar in design and capabilities to these:

https://www.amazon.com/dp/B08979VKVL/ref=cm_sw_r_other_apa_i_F38fFbY323VJV

https://www.amazon.com/dp/B07MK2WBPQ/ref=cm_sw_r_other_apa_i_.48fFb7H1YDPD

https://www.amazon.com/dp/B087JG5V8Y/ref=cm_sw_r_other_apa_i_m88fFbQM926CQ

https://www.amazon.com/dp/B07VSD3MK5/ref=cm_sw_r_other_apa_i_c98fFbR2AV4JV

Any expert input on which, or any oother options not show would be best suited?most practical Would be greatly appreciated.. The only problems that I have with either of these devices is current limitiations. On almost all Ive seen, the current limits are below what the system will call for.

A few other questions about Power Supply and system function if someone would please take a moment answer id greatly appreciate it.

1.Would batteries-in-series or batteries-in-parrallel be more ideal in this setup? I understand the diffference between how theyre set up. But understand nothing about the implications each has inside the system.

2. In a previous post here last week, the comment was made to me "Multiple power supplies in a single system can be problematic". Duly noted. Whart about running one supply for each barttery individually. TWO systemss?

3. The jump from 7.4 to 12V already seems drastic to me and likely to have consequences at some point. How sustainable is it to to continually operate a 12 Volt system on a 3.7 Volt Battery?

4. With the onboard BMS board, is running a single supply hooked to a single battery while the other battery is wired in so that is actively charges the battery hooked to the power supply? Is this a possibility?

5. What exactly are the effects on a system, during operation and over time, of running a system thats having to make such a large voltage boost. I may not understand electronics, but in every other kind of field that I do have experience, If youre having to constantly supplement 50 to 75% of the power you need then you usually have a very large problem and might even be borderline on the verge of a catastrophic failure;.

Is the answer to all of these questions, "Stop being so fucking cheap, forget about the space issues and buy a 3rd battery so you can get up to 11.1 volts because stepping down can be done in a much smaller space and and have to deal with this shit.

Again, I appreciate the time youve taken to readn and answer any questions. Any suggestoins uoui have about anything are gladly welcome and will be received.
 

KeithWalker

Joined Jul 10, 2017
1,154
That is a lot of information and a lot of questions.
Let us define exactly what you are trying to do:
Are you proposing to add LED lights to an existing drone?
If so, what type and how many are you proposing to use and what is their power requirements?
What are the specifications of the drone?
Without that information, I can not even start to answer any of your questions.
Regards,
Keith
 

Thread Starter

Stillers48

Joined Jul 12, 2020
21
That is a lot of information and a lot of questions.
Let us define exactly what you are trying to do:
Are you proposing to add LED lights to an existing drone?
If so, what type and how many are you proposing to use and what is their power requirements?
What are the specifications of the drone?
Without that information, I can not even start to answer any of your questions.
Regards,
Keith
It is being added to an existing drone but this isnt a custom built FPV Racing-style drone. Its commercially manufatcuted with closed source software and leaves virtually no options on the table for customization. Including tapping into the system power supply. The drone utilizes a "Smartbattery". It is aware of every single electron inside everey single circuit pathway at any given moment. Any attempt to siphon, shunt, or draw on its power system and it enters emergency "RTH" mode and wont take off until corrected. So, while my lighting system is going to be "Onboard" it is also going to be completely independent of the drone.. The only thing that the drone will be able to tell is that it suddenly weights about 100 grams heavier and its landing gear seem to be 2 inches lower than they used to be. As for the LEDs? I havent entirely completed mapping EXACTLY how and what im going to do. But i have a generally specific idea and am walking in that direction until my 3D printer guy can finish what hes woriking up for me on this project. When I know exactly what I have, ill know exactly what Ill do. But, I do know that its going to be a mixup of of different lights and functionability. This can be broken into two very different arrays. The first is constructed entirely of analog led strips that im planning to use. these are just simple analog strips varying from 3 to 6 in length with a parent microprosser driving them. All of them were purposed for the FPV Racing market. They all operate off of 5 volts, consume very little power, and short of a few preinstalled basic "blinky blinky" modes, are pretty generic and unintuitive. At most, will be 4 microprocessors, 1, maybe 2 UBECs for voltage regulation and 60 individual LEDs. Tops. Their greatrest technological feature is the ability for remote I/O. And then theres the the 12 Volt side of things. And this is really where I begin to get over my head. I could do the 5V stuff well enough I feel. The 12 Volt side I would like to be a multi-faceted array of 5050 SMD RGB Leds. The bulk of these will be built into flexible strips attached to the undersides of the motor arms running out to the end and then back into the core of the drone. At current moment, the strips and drivers I have are 5V but thats because botched it when I placed the order. I meant to get 12V. I dont have enough UBECS to support them on the 5V side and Im gonna need the Power supply on 12 volts. I also have 5 pairs of "demon eyes" Leds that will be arrayed around the drone as accent lighting. and one 12mm pair that will be the drones "eyes". Red in color of course. They are 5050s on account of the angel/demon effect but are not addressable or programmable and require no more than power, ground and remote I/O.. While not directly part of the light arrays but probably the second most critical components of the system will be two remote controlled relay switches, each with its own receiver, and one remote controlled switch without an attached relay. Al;so with its own receiver. All 3 are 12 volt. I havent entirely dectermined what technology the remote capability will operate on. Im still looking into IR, Wifi, RF. UART, TTL, LoRa, and (cost dependent) even cosidering using GSM technology over the cellular network. UART, TTL, and LoRa are new technologies to me. Going that route would require more than just buying parts on my part. Thanks to the FPV world 5Ghz transmitters and receivers are laying on every corner. And almost all drones are built arround that technology. But most are designed for video feeds. Not direct interfacing. Im not well versed enough to say for certain if that technology could be repurposed or not. Or how to go about it if it can. IR is too unreliabe with too short of a distance. Now, I would never do anything like willfully break FAA rules regarding personal drone use. But if someone told me that they had a drone identical to my sons up to 4000 feet once, Id believe them. Youre not toggling IR at that range. So short of a technological breakthrough on my end in regards to the other technologies available, RF is the clear front runner. Ive found a few 2-4 channel RF remote transmitters that claim to have ranges of up to 5Km. Seems like an awfully powerful device to offer for public use. The FCC keeps a pretty hard ceiling over consumers when it comes to power, signal strength, and range of the devices were allowed to have and operate. From what Ive gathered. They actively try to prevent us from getting our hands on anything that would allow us to get far enough away from a bomb to avoid being caught in the explosion yourself if you hooked one up to a bomb. Smart strategy I suppose. Even the available systems readily out there are usually dedicated , purpose-built set ups that would require engineering and tech know-how to repurpose.. All in all its just a big box filled with techy, flashy little things that i threw in a box and got the wild idea to build a franken-drone with.
 

KeithWalker

Joined Jul 10, 2017
1,154
So you have lots of ideas but have not yet decided exactly what you are going to do! At this stage, the only advice I can offer is to suggest that you start documenting what you would like to do. You have so many different ideas that you should break it down into separate projects.
You obviously have size and weight limitations. I suggest that you start with a feasibility study to find out what maximum weight the drone can lift without compromising its performance. You also need to do the same with the physical size and shape of the package.
Then you need to document the power requirements of the different lights you want to use. Your final choice will be limited by the weight and size of the power source required.
You will need to design your own microcontroller circuit to interface with a radio control receiver. Do you have the knowledge and experience to do that?
We are here to offer our advice based on our many years of experience. We will answer your questions to the best of our ability but we will not design your proposed system for you.
Regards,
Keith
 

MrChips

Joined Oct 2, 2009
21,689
Sorry, engineering is a discipline. if you are not following that discipline as the previous members posted then you are just flying by the seat of your pants. Engineering also means organization and communication hence the previous members' comments.
 

Thread Starter

Stillers48

Joined Jul 12, 2020
21
The size requirements I've got nailed down. The drone, in original condition, didn't have anywhere near the space to accommodate a system such as this. So, I had to cheat. The drones shell has a bottom plate that mounts flush across the entire bottom the drones body. Directly above it, when removed, is all of the drones on board systems. They are attached to the upper shell. There was two sensors and one cooling fan along with some vents attached to the bottom panel. Piece of cake fix. I drew out some rough drafts and came up with an "insert" that would create an extra compartment in the drone for. The hardware. All it consists of is a piece of plastic that matches the contour of the two original pieces and will seat with each one exactly the same way and with screw reliefs in the same spot to fasten them together. Encountered a few bumps in the process. Accommodating the cooling fan and the vents was a challenge and having to design new landing gear was totally unforseen. The panel caused the drones belly to sit lower than the stock gear. But I received alot of help form a young man down at the 3D print service whose help has been greatly appreciated! The insett should be done next week. The result was creating an available space that will be nearly exactly 60 mm x 140mm x30mm+/- 5.the length and width are exact. The height is fairly accurate. See that's why my work up on the actual application phase of this is a bit behind. Because no amount of planning and designing and knowledge would matter if I didn't have a place to put it. Lol. And, I do realize that I'm probably cutting some corners here and there that will cause some to either laugh in ridicule or become mad with rage, but all I gotta do is get a bunch of light bulbs and a few batteries to go up in the air and blinky blinky for 10-15 minutes max. Thats it. My next primary "go/no-go" focus is on, as you said, can the drone take it? I'm gonna put it in hover mode and time exactly how long it can hover on a fill charge. Then I'll add weight and repeat until I begin to see a marked effect on flight time. Then I'm gonna add more weight to find out how much buffer exists between compromised operation and causing flight instability or failure to launch. I feel that should be conclusive enough to give me a hard limit on how much extras I can pack on. I did do a rough calculation on required power in the very beginning. It wasn't exact. I used manufacture specs to run it out. The math suggested that all of this would need about 4 Amps. I should have plenty of battery power to cover that. 7.4v and 5000mAh from the batteries. The power supply will change thet of course. As far as micro controller for the remote controls? It's looking to be alot simpler than thst. I actually found a 2/channel RF Remote relay switch thats designed for ranching or oil field applications. It's designed to turn water pumps on or off from a distance and claims it has a 3000 meter working distance. If it has a 3th of that it'll have all I need. All I'd have to do is plumb it in and bolt it down and we'll be flippin switches. Now thst I for sure have a spot to buy all this I can move forward with bench testing and get some hard numbers on the performance and see what will and won't work. Then work off that.
 

Thread Starter

Stillers48

Joined Jul 12, 2020
21
Sorry, engineering is a discipline. if you are not following that discipline as the previous members posted then you are just flying by the seat of your pants. Engineering also means organization and communication hence the previous members' comments.
Believe I stated from the very beginning that thst was EXACTLY what I'm doing. I never once claimed to be an engineer. If I was, I'd hope I'd be good enoughat it to be above seeking advice on an internet forum.

It should be noted that I don't receive negativity very well. At Al. Ever. If you want to contribute, contribute. If not, roll on. Im just tryin to build something for my boy and avoid blowing up or crashing his drone in the process. I didn't realize that a degree was required to do so.
 

RPLaJeunesse

Joined Jul 29, 2018
109
Forgive me but as an engineer I find your long verbage responses hard to get through and harder to follow. My philosophy is KISS. Can you boil your problem(s) down to simple steps so folks can approach each one individually? My questions: How many watts will all your goal loads take? How many watt-hours does the battery system hold? Now take 70% of battery capacity to allow for typical control losses. Divide the first into the second's result, is the run time long enough? If it isn't, stop here and rethink what is possible, or how to do it. Only after that should you go on to the next step. Make a bullet list of constraints. Make a bullet list of requirements. Make a bullet list of "would be nice". Present the lists, solicit comments for how to achieve.
 

crutschow

Joined Mar 14, 2008
25,273
It should be noted that I don't receive negativity very well.
Then it be a good thing to learn to take constructive criticism here, since you are likely to get more of it.
But you are perfectly welcome to look for other forum that will treat you more kindly.

Writing short, concise paragraphs is essential to the proper discussion of technical information.
A stream of consciousness approach where thoughts are jumbled together without organization is not conductive to that.
It's not necessary to be an engineer to write concisely.
 
You really do have to minimize the words and separate your thoughts.

Preamble: My kid...
What I'd like to accomplish:
Knowns:
Unknowns:
Constraints:
My proposal:

The key is to organize your thoughts. Putting all of your toys in a toybox - No. Putting them on shelves grouped by function - yes. You want ot be able to proudly present your toy collection to others.

When I did programming for a large project there was:
If I had all the money and time what would I want this program to do?
What do I have to have?

It set a nice stage where the program designed worked with no modifications for 17 years before obsolecence took it's toll. It had places to go, but constraints, mainly memory and the operating system and cost, prevented it from going there.

Spreadsheets were not invented yet, but it was almost possible to generate columns of numbers. The constraint by the system was you could add J K S or T thermocouples in groups of 4 at at time. Software thermocouples and or hardware conditiioners could have been added.

It was for an in-house project. It took 9 months for 2 of us to do it.

Start by re-writing what you already said. Re-enforce with an outline.
 
Last edited:

LowQCab

Joined Nov 6, 2012
41
Let me save you some time.
A-Number-One, Weight is ULTRA CRITICAL on a Drone, ESPECIALLY the small commercial toys.

2, Because of the weight problem, you will need to use the on-board battery pack for power,
an additional battery is probably not a viable solution, it may not have the power to lift it.

3, Have you tested to see if on-board battery power is available at the charging connector ?,
it probably is.
Most commercial toys do not have a removable Battery Pack, but they have to be charged some way.
Find a compatible Plug for the Charging Jack,
this will be your power source and eliminates the need for a power switch.

4. Start searching the Internet for flexible printed tape with LEDs already soldered in place.
These are available with many different LED spacing's,
and with many choices as to the Current requirements per LED,
Usually, you will have to find the LED Current rating by looking up the part number of the LEDs
that are used in the particular strip you are interested in.
The LED part number is usually part of the Strip Assembly part number.
DO NOT get the type that is completely sealed in clear Vinyl and rated as "Water-Proof",
these are far too heavy for use on a Drone.

5, Usually, the strips will have a "nominal" voltage range that they are rated for, and there
will be pre-installed current limiting resistors built-in to the strip. BUT,
you can operate them at a reduced voltage, with a corresponding reduction in light output.
They will still be quite bright a night.

6, Guessing that you have a "2s" Li-Ion Battery, means that you have roughly ~8volts to work with.
8volts will operate LEDs rated for a "nominal" 12vdc, they just won't be as bright.

7, If you have a "3s" Battery, you will have a "nominal" 12vdc, and I'm very confident that
you will find many various LED Strips Rated for "12volts".

8, Buy 2, to 3 times more LEDs than you think you will need.
This is because the Strips are difficult to solder to, and you will need A LOT OF PRACTICE
before you get it right.

9, There are NO OTHER COMPONENTS, just 22gauge solid "hook-up" wire, LED Strips,
and a Charging Plug.

10, Don't ask for Flashing LEDs, unless you're a serious "glutton for punishment".

11, Don't ask for remote control of the LEDs for the same reason, and because,
your Drone probably can't deal with the extra weight of the parts required.
 

Thread Starter

Stillers48

Joined Jul 12, 2020
21
Forgive me but as an engineer I find your long verbage responses hard to get through and harder to follow. My philosophy is KISS. Can you boil your problem(s) down to simple steps so folks can approach each one individually? My questions: How many watts will all your goal loads take? How many watt-hours does the battery system hold? Now take 70% of battery capacity to allow for typical control losses. Divide the first into the second's result, is the run time long enough? If it isn't, stop here and rethink what is possible, or how to do it. Only after that should you go on to the next step. Make a bullet list of constraints. Make a bullet list of requirements. Make a bullet list of "would be nice". Present the lists, solicit comments for how to achieve.
Available power and power consumption isn't near the concern I'd originally thought. I haven't worked out an exact figure yet. I have a few more components to put on the meter yet. But having tested 75% of the onboard components it looks like I'll be coming in under 4 amps/50 watts. Total system capacity is 11.1 Volts/5000mAh on battery boosted and regulated to 12V,/2A/65W and only need to sustain power for 35 minutes max before the drone must land for and I was figuring on losing 40% of thst due to having to boost the voltage. Even if obky slightly.
 

KeithWalker

Joined Jul 10, 2017
1,154
Are you asking for expert advice or just telling us about your project?
If you need advice, just give us the necessary relevant information to define your problem please.
Keith
 
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