4s Miniquad Question

[brettp2004]

I've got a ZMR250 currently setup for 3s. I want to convert it to 4s. I know the motors and ESCs can handle the change, however part of the FPV system cannot. The FPV TX can handle 7v-24v, but the camera is 12v only. So here's my question, do I get a 12v regulator to step the 4s down, or do I just get a different FPV camera that can handle the 4s?

Also, if I go the 12v regulator route, will I still be able to run my 3s batteries for slow leisure flying? I don't believe I'll be able to, but that's why I'm asking the experts. Here's the Regulator I'm looking at getting.

If switching the camera is a better option, does anyone have a good recommendation for a camera that can handle 4s? Here's the one I currently have.

Also, is the flight control board effected at all? I believe it's powered from the 5v regulator on the PCB. Here's the kit I got if I'm left any information out.

The help is greatly appreciated!!!

 

[Craftydan]

Hey Brett

Looking at the frame in the kit you've linked . . . Have a look at the note between the 12th and 13th pic here:

http://www.fpvmodel.com/zmr250-v2-250mm-carbon-fiber-mini-fpv-quadcopter-frame-kit-with-pcb-board-and-led_g1005.html

It links to this regulator:

http://www.fpvmodel.com/mini-dc-dc-12v-voltage-step-down-regulator-module_g1045.html

Looks like it's designed as a drop-in to the frame that you have. Not too pricy and should be better than the regulator you linked -- Switching vs. linear.

There are other options, but they generally aren't as easy to use.

 

[brettp2004]

Yeah I saw that regulator. I have to order some other stuff from banggood so I was going to get it all together. But if that one is better I can do separate orders. But with that one would I be able to still run 3s batteries if I wanted? I don't think I can since its says output voltage is 1.2v less than input if it's below 13.2. So wouldn't the camera cut out since it requires 12v?

 

[Craftydan]

Hard to say. Most micro electronics don't run at 12v, but closer to 3-5V, so it's likely regulated after the input as well.

Typically buck switching regulators (like the one they recommend) won't cease to provide current when the input falls at or below their set voltage, however there is a voltage drop and it cannot regulate that voltage until it's back up. This means if you plug in a 12v battery to the regulator you'll likely get 10-ish V out, unregulated . . . which is only slightly lower and just as unregulated than the straight 12v connection.

If the camera is regulating down to a working voltage and 10-ish is enough . . .

Might work. Might not.


If you want a good option from banggood, I'd point you toward my go-to:

http://www.banggood.com/Small-Mini-360-Adjustable-DC-Power-Supply-Module-Mini-Step-Down-Module-p-917568.html

you will need to pull out a multimeter and micro screwdriver to set it, but solder it in then heatshrink it and it will tuck away into the tiniest of crevices.

It's also possible to short Vin and Vout with a switch to bypass it, so long as you NEVER flip the switch closed with 14V attached -- guaranteed to fry both the camera and the regulator. Another alternative is to connect the regulator in with male connectors on the input side and matching female on the output -- if you ever want to bypass it, disconnect the regulator and use the newly freed ends to bridge the gap. as before, never bypass with a 4S pack for the cameras sake.

 

[brettp2004]

Awesome thank you. That adjustable regulator looks like a good idea. What about just getting a camera that can handle 4s? Wouldn't that alleviate all the issues?

 

[Habakkukk]

Awesome thank you. That adjustable regulator looks like a good idea. What about just getting a camera that can handle 4s? Wouldn't that alleviate all the issues?

Yep. Here's the gold standard for most people nowadays. It accepts 5v-22v so your good for 4-3s. I've been flying these for a while now. Runcam makes a version with a plethora of mounting options, the "swift" I think. Can't go wrong with either. Beware the camera angle on the one I linked. It's 2.1 so your fov is greatly enhanced with the bigger lens, takes some getting used to.

 

[milkydeathgrind]

I just recently wanted to clean up my FPV set up so I did away with my need to plug in power to the TX separately via my battery balance plug and then the power ran from my vtx directly to the camera. I wanted a set up that would allow me to just plug in my battery (4s) and have everything all power up (including my vtx and camera). My camera is also rated for 12v so I was concerned that wiring all my video power directly to my PDB would be an issue but low and behold I wired everything the way I wanted it and it seems to work great.

Somehow this setup worked just fine for me using a 4s battery although my camera is supposed to be rated 12v. I don't know if the specs are just wrong or somehow this is just able to work.



Good luck!

 

[PsyBorg]

Don't some vtx's come with their own step downs for cameras? The kit I started with has the vtx using 7-22 v and it supplied 5v down to the camera on its own.

Maybe the OP wants to look at his vtx spec's first and see if it will do the same. That way he has clean voltage already without the need for filters and such if there is noise generated in his main power system.

 

[milkydeathgrind]

Oh yeah, later on I did end up adding a LC filter into the power loop to clean up the signal. This was just as easy as wiring it the same way in the diagram but with the lc filter in between the PDB and power and ground connections.

 

[PsyBorg]

I just did the same conversion as the new camera I am using is multi voltage so I pulled power from the aux tabs on the versa frame. Now I have that 1960's tv effect when I fly. Ill have to add a filter too as soon as I stop being lazy and research them.

 

[milkydeathgrind]

This one right here was perfect for me. It is cheap, tiny and easy to install.