#The 8th Lichuang Electric Competition#Desktop fan (desktop smoke exhauster)

 1. Project function introduction
This desktop fan was designed with reference to the previous two projects of Open Source Plaza.
The desktop fan adopts touch-screen stepless speed regulation and two power supply solutions: DC input and QC decoy input. The cost is extremely low, and the cost of counterfeiting is about 15 RMB.
 
2. Project attributes
This project is the first public, and has not participated in any other activities or defenses.
 
3. The open source agreement
adopts the MIT open source agreement. The design part mainly refers to the inspiration ideas of https://oshwhub.com/wzw666/yan-wu-jing-hua-qi, and the power supply part refers to https://oshwhub.com/LiiGuang/du-li-yuan-jianqc2-0-gu-ding12v-you-pian-qi.
 
4. Hardware part
The hardware circuit part is very simple and mainly consists of three parts:
(1) QC decoy 12V input
This part adopts the design of discrete components, and the Xiaomi power bank provides 12V/1.5A power input. 1N4148 provides a 0.6V reference voltage, 3400 and U11, 19, 20, 12 and R4 form a 0.6V input control on the delay D-.
Note: The specific values ​​of these five resistors and capacitors should be carefully debugged, which specifically involves the 0.6V delay time and the threshold voltage of MOS. It is recommended to purchase resistance components after testing in the simulation software.
(2)
There is nothing to say about the DC12V input. It is worth mentioning that for safety, fuses and TVS diodes are added to the input parts of the two power supplies. In order to control costs, these two parts can also be omitted.
(3) The PWM touch stepless speed regulation
project uses a four-wire PWM speed regulation fan. Since the speed feedback voltage is collected by the Hall sensor and jumps between 0-12V, the feedback part is not considered. According to the SGL8022W touch stepless PWM chip, two PWM complementary output pulses are provided (because some fans may control the speed according to the duration of the high level). Please short R5 and R6 according to the needs.
The setting method of SGL8022W is as follows: Use method 3-continuous PWM speed regulation with memory function.
Note: The fan has restrictions on PWM frequency, and low-frequency PWM touch chips may not be used.
 
5. The software part
is not programmed, is it very easy?
But it is recommended to simulate the five resistors and capacitors (if the MOS and resistor values ​​used are different from mine)
*6. The BOM list
is so cheap! The cost will not exceed 20! But it is recommended to buy it on Taobao, it is really cheap. . .
BOM_Supplier
Value
Footprint
Quantity
 
 
 
CN1
KF2510-4AGW-GW
LCSC
C722747
KF2510-4AGW-GW
CONN-TH_4P-P2.54_CAX_KF2510-4AGW-GW
1
U15
SS8050-HF
LCSC
C5179688
SS8050-HF
SOT-23-3_L2.9-W1. 5-P1.90-LS2.6-BR
1
R1
C0603X470M3HACAUTO
LCSC
C1623830
10nF
C0603
1
R2, R4, U8, U9
C0603X470M3HACAUTO
LCSC
C1623830
10uF
C0603
4
R3, U7, U10
C0603X470M3HACAUTO
LCSC
C1623830
0.1uF
C0603
3
Q1
KAO3400
LCSC
C2891617
KAO3400
SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR
1
R5, R6, U19, U20
PTFR0402B4K53P9
LCSC
C2692955
NC
R0402
4
U2
PTFR0603B2K05P9
LCSC
C2692838
47K
R0603
1
U3, U16, U17
PTFR0603B2K05P9
LCSC
C2692838
1K
R0603
3
U4, U5, U13
PTFR0603B2K05P9
LCSC
C2692838
10K
R0603
3
U11, U12
PTFR0603B2K05P9
LCSC
C2692838
470K
R0603
2
D1
SMBJ12A
LCSC
C719389
SMBJ12A_C719389
SMB_L4.4-W3. 6-LS5.3-RD
1
U1
SGL8022W
LCSC
C81650
SGL8022W
SOP-8_L4.9-W3.9-P1.27-LS6.0-BL
1
D3
ZMM5V1-M
LCSC
C8061
ZMM5V1
LL-34_L3.5-W1.5-RD
1
J2
TYPEC-304-BCP16
LCSC
C720629
TYPEC-304-BCP16
USB-C-SMD_TYPEC-304-BCP16
1
DC1
DC-044A-A200
LCSC
C720575
DC-044A-A200
DC-IN-TH_DC-044A-20A
1
U6
HT7533-1
LCSC
C2944149
HT7533-1_C2 944149
SOT-89-3_L4.5-W2.5-P1.50-LS4.2-BR
1
U14
SML310BATT86
LCSC
C9900000818
SML310BATT86
LED0603-RD
1
U18
1N4148/SMB
LCSC
C9900024333
1N4148/SMB
LL-34_L3.5-W1.5- RD
1
F1, F2
1206TD-7AS
LCSC
C2838923
1206TD-7AS
F1206
2
 
 
7. Competition LOGO verification
 
8. Author's thoughts
The design of this project has a shell! It has a shell! But the 3D printing of major merchants is too expensive !
I have tried to assemble it, but I will not consider printing it because of the economic cost (the shell of the cat is twice as expensive as the body).
Welcome friends who have the conditions to help me try it.
PS: You can put some weights in it, which is affected by https:// Inspired by @MingYueYe from oshwhub.com/mingyueye/yi-yan-zheng-zao-jia-di-lian-fu- (space reserved)
9. Demonstrate your project and record it as a video and upload it
Note: Green The wire is a touch switch (I also save costs)