Mosquito Repellent
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The summer this year is too hot, the heat is not really a problem but mosquitoes ...! ,especially i camping.
So after i tried some solutions i got the idea to make an electronic mosquito repellent that i can take with me wherever i go. this circuit is just a transistor multivibrator that generates high frequency sound ,and mosquitoes don't like this sound.
I am not gonna use a PCB i will just solder components together to make it a simple and cheap
Update : here is the Kicad project + (the PCB , the schematic , the components view ) in PDF
Components
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- two BC548 transistors or equivalent
- two 100k resistors radio shack link
- two 1.5k resistors radio shack link
- one 4.7k resistor radio shack link
- one 2nF ceramic capacitor radio shack link
- one 560pF capacitor radio shack link
- 5mm Red led radio shack link
- Toggle switch radio shack link
- 9v battery radio shack link
- 9v battery snap connector radio shack link
- Piezo element radio shack link
- a small project enclosure radio shack link
- some wire
This components i salvaged them from my older projects ,but i put links to Radio Sack
Tools
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- Cutting plier
- Needle nose plier
- Solder iron
- Some solder
- Philips screwdriver
- Hot or super glue
Circuit Soldring
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solder the components in order like in the pictures
- Bend the collector and base pin of each transistor
- Solder the emitter pins together
- Solder the 560 capacitor then 2nf one solder the two 100k resistances then the other 1.5k
- bend the free pins of 4 resistance and so
Preparation
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- Make a hole for the toggle switch with the soldering iron then enlarge with the screwdriver
- Screw the switch in place
- Solder the 4.7 resistor to the positive pin of the led
- Make a side hole on the box with the soldering iron for the led
- Solder the led current limiting resistance to one one switch pin
- Solder two wires to the Piezo element ,positive pin is the middle disk
- Make a small hole on the lop next to the switch for the Piezo element wires
- Insert the wires in the hole and glue the Piezo element to the top
- Solder the red wire of the snap connector to the other pin of the toggle switch
- Solder the black wire to the negative pin of the LED
Final Assembly & Testing
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- Solder the common pin of the resistors to the pin of the toggle where the led limiting resistance is soldered
- Solder a wire from the emitters to the negative pin of the led
- Now solder the two piezo element wires ,between the positive and the 2nf capacitor junction with the collector
First testing:
- Connect the 9v battery
- Turn on the switch , the led should light
- If you don't hear nothing put in parallel a capacitor approx 100nf with the 560pf capacitor ,if you hear a buzz everything is alright ,you're just not sensible to the high frequency
- Put the battery in place and close the box
final word:
If you are sensible to the high frequency this can drives you nuts