The article is being published in collaboration with JLCPCB. They supply high quality PCBs at a very reasonable price. They also can provide SMT circuit assembly.
We thanks to our sponsor JLCPCB for sponsoring us PCBs for this project circuit.
For SMT Service, Click here .

Thanks To JLCPCB.
$2 for 1-4 Layer PCBs.
Get SMT Coupons - https://jlcpcb.com/RTA
In this project circuit, we will teach you making a good quality flip-flop circuit. A flip flop is an electronic circuit with tow stable states that can be used to store binary data. Then stored data can be changed by applying varying inputs.
Flip-flops and latches are used as data storage elements. This is a bitable circuit concept in which it has two stable stages either On or OFF. It is kind of circuit that changes back and forth between two states (on and off) at certain intervals.
Flip-flops maintain their state indefinitely until an input pulse called a trigger is received. It flips into one state, than flops to another and so on.
Component List -
To make this flip-flop circuit, we might need some electronics component.






All Component list have to been given below –
- Transistor – S 9013 * 3
- Resistor - 10 K Ω and 560 Ω
- Capacitors – 100µf/ 25 volt *3
- LED (3 colors)
- PCB (made by JLCPCB)
- Power source – DC 12v
- Soldering iron
Applications of transistor -
- High-frequency amplifiers
- Switching converters
- High-current drivers
Feature of transistor -
- 25V collector-emitter breakdown
- 500mA collector current
- Gain min. 40 and max. 300
- 140MHz transition frequency
- TO-92 package with 650mW power dissipation
Pin out of transistor -
A transistor is a miniature semiconductor that regulates or controls current or voltage flow in addition amplifying and generating these electrical signals and acting as a switch/gate for them.
In a simple word a transistor is a solid-state electronic device that is used to control the flow of electricity in electronic equipment and usually consists of a small block of a semiconductor.

Its 3 legs pin-out can be seen above -
- Emitter
- Base
- Collector
Schematics and PCB Design -


The schematics of PCBs can be seen above.
Hardware of Flip-flop Project Circuit -

To make this mini flip-flop circuit, we might need some electronics component. JLCPCB has its own parts library. JLCPCB has 200k+ in stock components, 24 hours rapid SMT assembly.
You can check SMT parts library here - https://jlcpcb.com/parts
Circuit Connection – Step 1
To make this flip-flop circuit, 1st we connect 3 pieces 10 KΩ resistor with “Base” leg of transistor. Then we connect 100µf/25v capacitor negative leg with “Base” leg of transistor and its positive leg with other transistor “Collector” leg. We follow this process with the rest
capacitor also and connect its empty terminal with 3 legs of 10 KΩ resistor.

We utilize JLCPCB https://jlcpcb.com/RTA to printout our PCB.
Circuit Connection – Step 2
To make this flip-flop circuit we are using 3 different color LED light, as a like red, green and blue. For this 3 different color we make different set led light and we connect all LED negative leg with each other. Then we connect all red color led positive leg, blue color led positive leg and green color led positive leg.


Connect red color led positive leg with each other, blue color led positive leg with each other and green color led positive leg with each other.
Circuit Connection – Step 3
Now we connect this 3 different color LED positive leg with 3 different transistor. Our circuit is now completely ready for use. You can use this circuit to decorate your home, office and can use any cultural program.


To operate this circuit, we need DC power source. We are using DC-12v power supply to operate this circuit. We connect dc 12v positive cable...
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Not a flip-flop, but a chasing light circuit.