KIT INCLUDES :
- Resistors (10K – 2 & 470 ohm - 2)
- Capacitor 100 µf – 2
- Breadboard 830 pt. – 1
- Transistor BC547 - 2
- Single stand wire 2mt – 1
- Led 5 mm – 4
- 9v Battery - 1
- Battery snapper – 1
Introduction
In this video we will make a Flip Flop Led Flashing circuit using Resistors and Capacitors. This circuit is actually an astable multi-vibrator which starts blinking leds one by one when power is applied. This circuit can be operated with any 6-12v voltage source. You can also operate the circuit by changing the values of the current limiting resistors R1 and R4 to 390 ohms
HARDWARE REQUIRED
- Resistors (10K – 2 & 470 ohm - 2)
- Capacitor 100 µf – 2
- Breadboard 830 pt. – 1
- Transistor BC547 - 2
- Single stand wire 2mt – 1
- Led 5 mm – 4
- 9v Battery - 1
- Battery snapper – 1
SPECIFICATIONS
Led
Capacitor
BC547 Transistor
CIRCUIT CONNECTION
- Attach both transistor Q1 and Q2 to the breadboard
- Connect 10K Resistor R3 to the Base terminal of the Transistor Q1 and the other leg of resistor to the different column for further connection.
- Connect Another 10K Resistor R4 to the transistor Q2 similarly.
- Connect both the rest terminals of 10K resistor with hook up wire.
- Connect negative leg of the 100uf capacitor C1 to the base terminal of transistor Q1.
- Similarly connect the another 100uf capacitor to transistor Q2.
- Connect 470-ohm Resistor R1 to the transistor Q1and the other terminal to the different column.
- Connect 470-ohm resistor R2 to the transistor Q2 similarly.
- Connect positive Terminal of Led 1 to the Rest terminal of 10k Resistor R3 which is directly connected to the transistor Q1.
- Connect the Led 2 Similarly.
- Connect Emitter pin of Transistor Q1 to the Collector pin of Transistor Q2.
- Connect collector pin of transistor Q1 to the positive terminal of 100uf capacitor C2.
- Connect Emitter pin of Transistor Q2 to the positive leg of 100 uf Capacitor C1.
- Now connect the positive terminal of battery to the positive terminal of led 2 and the negative terminal to collector pin of transistor Q1.
WORKING AND OUTPUT
After connecting the battery. you can see both the leds will light up in flip flop mode due to the delay created for each of the cycle. When the capacitor and resistors are made equal, each led flashes for the same length of time.
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