quadcopter battery

Other Hardware General Electronics
1

Hello! I am trying to make a quadcopter, with this set: https://www.amazon.ca/gp/product/B00Z0EMCLQ/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

and an ATMega328P chip(with oscillator and capacitors), and 4 TO-220 Mosfets(for PWM in the future)

Four digital pins on 328P are connecting to Mosfet gates; drain pins on four Mosfets are connecting to battery positive; all GNDs are connected together. At this stage, those 4 gpio pins are just set as HIGH, not using PWM yet.

My problem is the battery. I tried with 4 rechargeable Ni-MH 1.2V AAA batteries, but neither connecting motors to complete circuit, or directly to battery, motors are not spinning fast enough to lift. It is even worse in the case with circuit.

On internet, I found many 3.7V Lipo batteries like this: https://www.amazon.ca/dp/B01M0I7HTC
Will they be better options?

So am I doing anything wrong, or missing any important point?

Any suggestion is appreciated. Thank you!

2

LiPo is basically a requirement for flying - nothing else comes close for power-to-weight ratio, which is
pretty much at the limit in electric rotor-craft. Something like 20+C or so discharge rate is likely
to be needed - low current batteries are never going to work.

Hover flight takes huge amounts of power.

3

What type of MOSFET are they? A circuit diagram showing how the MOSFETs and motors are connected would help.

NiMH batteries are very heavy. Lipos should be better and 650mAh should be sufficient but I wouldn't buy any lipos that do not specify a C-rating...it's an important characteristic.

Steve

4

drain pins on four Mosfets are connecting to battery positive;

Don't sound right, post a wiring diagram.

5

actually I meant to say source pin, not drain. sorry about confusion

and here is my circuit. I am new to circuit drawing software, so my arrangement is not good, hope the colors will be helpful.

quadcopter circuit.JPG
quadcopter circuit.JPG1305×744 73.3 KB

6

That's not how you connect an n-channel mosfet to a motor.

Batt(+) goes to all the motors(+).
Motors(-) to the drains (middle pin of mosfet).
Four sources to battery ground and Arduino ground.
Gates to Arduino pins (should use resistors).
Also add four schottky diodes across the motors, to protect the mosfets.
Look at the first diagram here.

Post#2: "What type of MOSFET are they?"
Leo..

7

Thank you! does this circuit look better? and btw, these mosfets are P30N06LE. For the diodes, can I use some regular diodes, like 1N4004; or have to use schottky diodes?
For battery, Lipo battery is the only solution, right?
if so, can I use a single 3.7V (for both of motors and Atmega328P), or use 11.1V battery and 5V regulators?

newCircuit.JPG
newCircuit.JPG1341×816 90.5 KB

8

Yes, P30N06LE and cicuit are ok.
The 1N4004 is ok for a relay (on/off once), but not recommended for fast PWM.
Could use a 1N5819 for small motors.
You had the correct LiPo advice in post#2
Seems the motors are made for a single LiPo (~3.7volt), so stick with that.
A small boost converter, powered from the same battery, could power the Arduino.
Leo..

9

Use 150 ohm gate resistors, better efficiency with PWM, less heating of the MOSFETs.

10

MarkT:
Use 150 ohm gate resistors...

There is a link to Nick Gammon's mosfet page in post#5.
OP probably forgot to change values is Fritzing.
Some resistors are 100ohm. others are 1k.
Leo..

11

A good start is to weigh the copter with whatever battery you choose.
As a general rule it takes roughly 150W/Kg to make a copter hover, more to make it do anything else except landing.
If you have an idea of the power consumption, then this will provide a guide as to what battery chemistry to use,
but pretty much all copters use Lipo with C ratings of at least 20.
If you want mega performance , then 90C batteries are available, but are expensive.