Showing posts with label multivibrator. Show all posts
Showing posts with label multivibrator. Show all posts
Thursday, November 13, 2014
Astable multivibrator 2 LED flashing circuit 2N3904 3 7V
Many of my friends asked me for automatic on off led circuit or led flashing circuit so here I’m going to post a Astable multivibrator-2 LED flashing circuit.
It is a simple astable multivibrator circuit using 2LED (here i used red LED), two NPN small transistor 2N3904 for switching. Here other small NPN transistor can be used, including 2N4401, 2N2222 or PN2222. Supply voltage is +3.7V to +5V or if you want to supply a larger volt then add a required resistor series connected with 2 LED’s. I recommend to use +3.7V for best result . for +3.7V you can use a battery of mobile phone.
The 5K ohms resistor and the 220uF capacitor determines the LED on time(flashing) for each side. You can experiment by changing the 5K & 220uF value.
Pin diagram of transistor 2N3904:
Circuit diagram of Astable multivibrator with 2 LED:
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| Fig: Astable multivibrator-2 LED flashing circuit Circuit diagram |
The 5K ohms resistor and the 220uF capacitor determines the LED on time(flashing) for each side. You can experiment by changing the 5K & 220uF value.
Pin diagram of transistor 2N3904:
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| Fig: 2N3904 Pin Diagram |
Sunday, August 24, 2014
Simple Christmas star from multivibrator Wiring diagram Schematic
This is so simple schema But you can use this schema as a Christmas star.Here I have used famous transistor 2N3904.If you are unable to find this transistor you can use D400 instead of that.This schema operates with 9V.I used this schema for the last Christmas If you used Blue color LED s It would give inexpressible attraction.
Note
# If you want to change the speed of this schema You can do it by changing the values of 10uf and 100k
# This schema can be operated with 9V power supply
# Fix this schema on a pcb
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