Is PDB built into ESC/FC/Stack?

C

calvinbun

New Member
So I watched some of JB's videos and also did some of my own research, but I am really confused.

I haven't seen JB mention Power Distribution Board (PDB) at all, but apparently, it seems very necessary.
Thread to the discussion I read: http://quadcopterforum.com/threads/power-distribution-board-vs-esc.19213/

I am trying to build a 5-inch freestyle quad, and I can't sort out the difference between ESC and PDB yet. Do I even need a PDB for a 5-inch freestyle?

So far, it seems like the ESC is built into the PDB or vice versa. For example, I intend to buy this stack, and it only says FC + ESC. Where is the PDB?

Hopefully, someone can help me figure it out, Thanks a lot!
 
In general the "PDB" is a thing of the past, typically the "all in one ESCs" will basically take the power in from the battery and has regulators for powering the ESC chips. The PDBs were a thing when the 4 in 1 ESCs didn't exist and so you needed to split power out to all the individual ESC and was basically job of the PDB to have regulators on board and enough pads to wiring everything to the appropriate voltage regulator. Nowadays the FCs often have lots of pads for supporting DJI cams (think 9V) or 5V pads and with 4 in one ESC basically just need the "communication"/signal wires hooked up between the FC and ESCs and battery power going into both the 4 in 1 ESC for it to distribute power/drive the motors and battery power going to VBAT line on the FC so it's regulators can step down the voltage for the FC MCU/ICs. Make sure the input range of your FC and 4 in 1 ESC matches the batteries you plan to use but otherwise should be fine.
 
Basically if you had a component that needed more current at one of those voltages then you might want a dedicated PDB still or some buck converter/regulator that can flow more current without cooking itself, but should be fine. If this is your first ever quad I'd suggest either build a small guy or also buy a small guy like the tiny-hawk or competitors in the oversized tiny whoop category since can still get some oomph with them and learn to fly just like the bigger quads but less likely to explode things catastrophically and need to rebuild right away/all the time.
 
wafflejock said:
Basically if you had a component that needed more current at one of those voltages then you might want a dedicated PDB still or some buck converter/regulator that can flow more current without cooking itself, but should be fine. If this is your first ever quad I'd suggest either build a small guy or also buy a small guy like the tiny-hawk or competitors in the oversized tiny whoop category since can still get some oomph with them and learn to fly just like the bigger quads but less likely to explode things catastrophically and need to rebuild right away/all the time.
Click to expand...
Thanks Wafflejock!
Btw I was just also wondering, do all goggles bind with all VTXs?
 
calvinbun said:
Thanks Wafflejock!
Btw I was just also wondering, do all goggles bind with all VTXs?
Click to expand...
No prob. You just reminded me I need to fix one of my VTXes :D the antenna mount broke off the board cause a zip-tie gave out and the antenna was still stuck to the quad but VTX cam free and broke that connector (I think I have a spare here somewhere).

Regarding the compatibility for VTXes there's two major "groups" or "types" of VTX analog or digital. Within Analog basically everything is using a channel of bandwidth around the 5.8GHz signal and it's all basically the same type of Analog signals as old over the air TV so there is broad compatibility for any 5.8GHz analog transmitter and receiver for video. If you start looking at the digital side of things it gets a lot more confusing, basically this is where everyone is competing today to capture market share and be the best of the bunch so there are a handful of competing protocols from different brands. If you are buying a digital transmitter for a given digital receiver you'll want to buy them as a pair or look for compatible with X digital system. Oscar Liang's site is a gem in general and just doing some searching end up there with regard to what digital systems are available today:

oscarliang.com

Which FPV System Should You Buy in 2025? Analog, DJI, HDZero, Walksnail Avatar - Oscar Liang

Entering the world of FPV drone flying can be quite daunting, especially with all the different FPV systems available to choose from: analog, DJI, Walksnail and HDZero. Understanding the purpose, cost, and capabilities of each…
oscarliang.com oscarliang.com

many higher end goggles will have a "module bay" for putting in different receivers and are like "dumb (but pretty) displays" with the smarts for decoding signals baked into the receiver modules themselves
 
I personally have one quad with an analog transmitter on it (the stuff I learned with) and one with a DJI air unit on it (because they had a sale and the digital was too tempting not to try). I mostly fly the digital now just because it's a nicer view while I'm flying, and the latency isn't enough to matter unless you are doing some sort of competitive flight, the analog is my backup for when I inevitably break the digital system (like now) which is more expensive to replace.
 
wafflejock said:
I personally have one quad with an analog transmitter on it (the stuff I learned with) and one with a DJI air unit on it (because they had a sale and the digital was too tempting not to try). I mostly fly the digital now just because it's a nicer view while I'm flying, and the latency isn't enough to matter unless you are doing some sort of competitive flight, the analog is my backup for when I inevitably break the digital system (like now) which is more expensive to replace.
Click to expand...
Thanks again WaffleJock. I was also wondering if I needed to buy the chunky capacitor thing that is soldered in w/ the battery wires. Additionally, I do wonder if I need to buy the Radiomaster RP1 because I have a tx16s pre-installed with ELRS. If you have any ideas on parts I might miss, please do tell me. Thank you so much.
 
Yup that receiver should work with any 2.4GHz elrs transmitter I believe. The low esr capacitor on the power input is a mostly optional thing, it can basically help if the video transmitter/signal getting lots of noise when the motors are drawing a lot of current for short periods (basically helps to keep the voltage level while the current is getting drawn in bursts through the escs/motor coils is my rough understanding). Usually the 4 in 1 esc boards will come with the capacitor if they couldn't fit it on the board and or is "expected".
 
Only thing to watch out for there is the polarity on the capacitor (usually a white or solid colored band along the minus side). Regarding other stuff to buy I'd suggest a vifly v2 (or 3 if they have newer one) is basically little beacon that screams if quad power disconnected for too long or you can hook it to a beeper/signal from FC so can activate with switch but basically helps you find a quad if it falls in tall grass or you're just not sure where it went down. It can be a little bit annoying/frightening sounding but is a very effective beeper/light.
 
Back
Top