LED driver circuit
There would be hardly anyone who would not be aware with the term LED. It is used as an optoelectronic device and is a special type of diode. These LEDs which are considered to be the future of lights basically works on a LED driver circuit.
These tiny little circuits can illuminate a lot of area. The led driver circuit design is very simple and have the PN junction diode as the one of the major component. And, the best part about these circuits is that they are very less power consuming circuit and yet they produce much better illumination in the Power LEDs.
Principle of LED driver circuit
LEDs have become so common in such a short duration of time, because the LED Driver circuit does not require a transformer in the power supply. The driver circuit design contains AC capacitors which are connected in a line one after another. And, the basic function of these capacitors is to reduce the supply of the current. So, having capacitors is mandatory in high voltage circuits for their proper functioning.
Components of a LED driver circuit
- Electrolytic capacitor (non-polarized 2.2μF)
- Four resistors (1KΩ,10KΩ, 22KΩ, 390KΩ)
- Bridge rectifier
- Zener diode (4.7V)
- LED (Bright white LED)
- And, a polarized capacitor (47μF)
LED driver circuit design
There can be two major deigns for this circuit:
- To the main supply a main capacitor is connected in a line.
- Then, the resistor is connected in the parallel arrangement next to this capacitor. This resistor works as a bridge between the main supply and the rectifier.
- To filter the output of this circuit the Full wave Bridge rectifier is used in the design.
- Zener diode is used for controlling the Direct Current (DC) of the full wave bridge rectifier.
- The zener diode is usually connected after the series of resistor, so that it can limit the current.
- So, this complete led driver circuit design produces a regulated DC voltage which is given to LED for illumination.
Working of LED driver circuit
- The components on which this constant current led driver circuit diagram works are electrolytic capacitors, zener diode and a resistor.
- These are must to have components for the circuit to work.
- The capacitor limits the current. It limits Ac current as it is connected to the main supply.
- Then, this output current enters the full wave bridge rectifier. So, basically the current entering the rectifier is already filtered by the capacitor.
- Then, the rectified DC voltage is generated which goes through a zener diode.
- A zener diode which is acting as a regulator, majorly considers three important factors, namely
- Resistor’s power rating
- Zener diode’s power rating
- Series resistor
- And, this diode is connected next to the resistor for limiting the flow of current.
- Then, the power rating of the resistor is calculated.
- So, the regulated and rectified voltage produced as the output.
- And, this output is given to the Led and the circuit is completed.
Also watch Half wave Rectifier
Applications of LED driver circuit
- It is widely used in our homes for the lightening purpose, as LEDs have almost taken over the normal tube lights.
- It is also used in car, bikes and various other automobiles as an indicator.
- This circuit is also used in the combination with the doorbell to provide the indication.
- It is used in various domestic applications like commercial and residential lightning.
The future of electronics lies in the LEDs as they are useful as well as cost efficient.