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Topic starter
2026-04-03 2:40 am
Hey everyone,
The weather’s been really weird these past few years, and I’ve already been plagued by mosquitoes way earlier than usual this time around. Fed up with the nuisance, I decided to tinker with a little project in my spare time—a smart touch UV mosquito killer night light that combines a few practical functions into one compact device. Turns out it actually works to some extent, so I figured I’d share the details with the community!
It’s controlled by a SOP-8 MCU, with single-touch 3-color dimming for the night light, and it triggers UV light plus an intake fan for physical mosquito killing. No fancy components, just a mix of embedded control, power management and simple mechanical design, all packed onto a small 60*48MM FR-2 PCB.
Core Hardware & Basic Function
- Main control: SOP-8 MCU (supports touch control, MPT rewriteable)
- Power management: 4056 SOP-8 lithium battery protection chip (1A max current, charges a 1200mAh 18650 cell in ~4hrs)
- Switches/Drivers: 3x SOT-23 MOS 2302 for light/fan on/off and circuit protection
- Optics: UV LED beads, cool/warm white LED beads (3-color dimmable via touch)
- Mechanics: Small DC motor + intake fan (physical mosquito capture)
- Power: USB-C 6P port, 3C certified 18650 battery (works during power outages)
It’s a common-mode dimming design with full charge/discharge protection, and uses pure physical mosquito control—UV light lures mosquitoes in, then the fan sucks them in. No chemicals, eco-friendly and safe for home use, plus it doubles as a touch-adjustable night light, so it’s pretty handy for daily life.
I got the basic prototype working and it just about does the job against mosquitoes, but ran into a few technical questions during development that I’d love this community’s insights on—right up the alley for embedded/power/robotics folks here:
- For the SOP-8 MCU’s touch control, I’m getting slight signal jitter with ambient temperature changes. What’s your go-to method for calibrating touch sensitivityto avoid false triggers on low-power embedded devices?
- The 4056 chip’s charging current is set by a single resistor (R11: 2-7K for ~400mA), but the battery voltage drops as it discharges, making the fan/UV light less stable. Are there lightweight passive current regulation tweaksto keep them running steady without adding a fancy DC-DC converter?
- The small suction fan has very limited airflow, but if I switch to a larger fan, noise becomes a big issue. I feel like I’m missing something in the mechanical or aerodynamic design—what’s a good way to balance suction power, fan size, and noise without just brute-forcing a bigger motor?
- Right now the UV light and fan run together non-stop when activated. What’s a simple way to add low-power motion/light sensing(on the same SOP-8 MCU) to trigger the mosquito killer only at night/when insects are near, to save battery life?
This is just a small home project that solved a real nuisance for me, but I’m curious to hear your best practices for low-power embedded design, power management and small-scale mechatronics. Feel free to share tips or ideas for improvements!
Cheers,Yassin
Yassin | Building Compact, High-Current Connections for Drones & Robots
tfpfau reacted
2026-04-09 9:44 pm
I think those devices suck mosquitoes in more by chance than by attraction to the UV light they work best when humans aren't there as CO2 and lactic acid are what they are really attracted to. You might like to add CO2 to the mix as I think such traps work best. They are also attracted to damp places so a good place to have a fan going to suck them into an electric mesh.
Topic starter
2026-04-14 1:18 am
Thanks a lot for the tip! That makes a lot of sense—I’ve been noticing it only catches mosquitoes occasionally, and your explanation about CO₂ and lactic acid being the real attractors really clarifies why. I hadn’t considered that the trap works more by chance than pure UV attraction.
I haven’t really thought about adding a CO₂ source before, so I’ll need to look into safe, low-level release methods first. I’m a bit worried about accidentally making the local air quality uncomfortable if the concentration is too high, so I want to get that right before testing anything.
And I’ve also noticed something strange lately: mosquitoes these days seem really tough. Sometimes I hear the zapping sound, but there’s no dead mosquito left afterward. I’m thinking maybe I need to increase the voltage/current a bit to make sure it actually kills them instead of just stunning them.
Great practical advice—much appreciated!
Yassin | Building Compact, High-Current Connections for Drones & Robots