DIY battery management + handheld small fan debugging questions

se7ens

DIY battery management + handheld small fan debugging questions [Copy link]

 

 

I have made a small fan DIY before, and I signed up for this forum event. The manager was very helpful and arranged it for me.

I received the parts a week ago. I tried welding and found that the effect was not satisfactory.

Please help me with guidance from forum friends with successful experience

Unboxing photos

There are not many materials, but there is still no Peppa Pig, battery fan holder and resistor. Fortunately, I can disassemble them from other places.

Board

EE log on the back, with guest editing, and the packaging also shows that the materials are provided by LCSC

Weld a semi-finished product

Power on, full charge indicator lights up

Connect a small fan, and the fan light will turn on after pressing the button (if the fan does not rotate, it can be understood as no load)

Try changing a small fan. This is the case where there is no button. 0v

1st gear 5.45v

1st gear 6.05v

3rd gear 7.37v

Change the fan to 9.28v in the third gear (if the fan does not rotate, it can be understood as no load)

After changing the fan, all three gears are 4.14v (the fan is spinning, but the speed does not change after changing gears)

Attached is the schematic diagram and function output introduction

At present, it seems to be overloaded (the fan with blades has too much power. After changing to another fanless motor, the speed can be adjusted by shifting gears, but the speed of gear 3 still feels too low)

The previous pitfall was that the inductor was 3.3 instead of 33 as shown in the schematic diagram, but after changing it, I still feel that there is not much improvement. I don’t know if there is a problem with the chip, but there is only one. I will find another one to try when I have time.

The subsequent plan is to connect this fan function to other control circuits after it is adjusted, such as a human body sensing switch or a shaking motor to achieve the effect of chasing people and delivering air.

okhxyyo

Got it~~ I'll call our friends to help you check it out

蓝色天使

I see, the fan wiring in the first picture where you measured the voltage with a multimeter is wrong, the positive and negative poles are reversed. Please check whether the positive and negative poles of the fan are connected correctly. I checked the voltage corresponding to the three gears and it is correct.

蓝色天使

Also, the wind speed will not change when powered by USB, it only runs at the lowest gear. It can be adjusted only when powered by battery. For debugging welding techniques, please refer to the debugging precautions posted on the forum for detailed instructions.

蓝色天使

Only the battery power supply has three adjustable levels, and the USB power supply can only run in low speed and shut down. Pay attention to the positive and negative poles of the fan. You can watch the operation video of the group owner.

lugl4313820

The ground of this chip is that big solder pad. I encountered the same problem as you at first. Later I took the chip off, applied solder to the ground, and then used an air gun to solder it back on, and then it was normal.

lugl4313820

I read the schematic diagram many times, measured it N times, and spent a day to get it right. You can try it according to mine.

se7ens

Blue Angel published on 2022-8-19 15:43 Also, the wind speed will not change when powered by USB, it only runs at the lowest gear, and the battery end can be adjusted when powered by battery. For debugging welding techniques, see the debugging posted on the forum...

Look at the voltage measured in my last picture. There is no change in the three-speed switch, but the positive and negative poles of the fan should not be affected. The DC motor only has positive and reverse rotation.

蓝色天使

The power supply can only be supplied from the battery and the voltage and output power meet the requirements to have a three-speed output USB interface. The chip detection is in charging state, with only low-speed and off functions.

EricCheng

Let's take a look and learn

吾妻思萌

Good stuff, I hope the OP can find the problem and post the experience

秦天qintian0303

How is this fan controlled? Voltage or PWM?

qingqi123

Come and pay respect to the boss and give him a cup of tea