China Made Portable Fan

Portable Fans have become more and more popularly used and seen every summer. I opened several budget models costing less than HK$100 or US$12.80. The one I found with a price tag just HK$25 or US$3.20 was worth opening to see inside how poorly made inside. I was surprised to find so many parts being used to control the motor and Li-Ion battery.

Size: 95 x 35 x 195mm (about 20cm high)
Weight: 160g
The photo dose not show but charged by a common USB connector included . It operates at three different speeds - powers but no power ratings shown in the simple spec. This is not a generic brand.


Motor Control side

AD1: 8-pin IC has no marking but＜555＞is seen near it on the PCB.
D2: A big diode SS34 (Schottkey) 3A 40V
Coil 4R7 (4.7uH)
IC2: A small 6 pin IC. The marking shows <BC71X> but not identified. As closed to SS34 and Coil L3: 4R7 this is supposed to be (dual) MOSFET? One dual MOSFET is found on the other side. Or <BC> may mean Boost Converter.
Two small SMT LEDs Green and Red for showing battery charging status.The marking on PCB are L1 and L2 not Dxx (of Diode).

The markings on PCB are modern, IC1, IC2, IC3 are used instead of U1, U2, U3 though U1 exists on the back. AD1 may mean Analog to Digital Conversion IC ?  But 555 is an AD Converter IC ? Yes. The following and some articles on the net

https://www.eeweb.com/circuit-projects/555-timer-as-an-analog-to-digital-converter
"
This 555 timer based circuit is a kind of voltmeter, also an analog to digital converter, that converts the analog input voltage to digital output pulses.
"
Wiki on 555 IC says

"
As of 2003, it was estimated that 1 billion units were manufactured every year.^[5] The 555 is the most popular integrated circuit ever manufactured.^[6][7]
"

But I have seldom seen 555 IC. This is not the first time to encounter but not often.


Battery Control side

IC1:  8-pin IC: TP4056 -  Lithium Ion battery charger IC
U1: 8205S - dual MOSFET
IC3: DW01A - Li-Ion battery protection IC
Q1: A1SHB - this is a marking on the part. P-Channel MOSFET. I found many different suppliers marking this part with their own part numbers like HM2301B, MS23P01S, even Si2305D, etc. but the same marking on the part. Strange. (*)
Q2: 2300 - N-Channel MOSFET (cannot seen in the above photo as located at the back of the connector.
As you can see (or cannot see)  below, these Q1 and Q2 are not used for Battery Control but for Motor control.

These three parts (+ two SMT LEDs) are found below (a copy and paste from the net)

I found the following on the net.

Here you are looking at the 3 chip breakout board (TP4056, DW01A and 8205A MOSFET).

TP4056 Breakout Board Schematic

So this design may be very common.


(*) ＜A1SHB＞ marking

HM2301B   H&M Semiconductor, Vishay
SI2305DS   SHENZHEN TOPSKY TECHNOLOGY CO.,LTD
2301L   Goford
MS23P01S   Bruckewell
Si2301DS    Vishay Marking  ＜A1SHB＞
Si2305DS    Vishay Marking  ＜A5SHB＞

ACT