DIY : Homemade multi colour LED light series

During the Diwali festival, we all want to glitter our homes with a number of sparkling lightning series of different colours like red, green, white, yellow, golden, multicolour etc. Similarly during marriage occasions in our families we decorate our homes with lots of such sparkling lightning series. Many people also put such light series to use in their personal temples or prayer rooms. Most of the community temples are also ornated with such light series at night most of the year.

Such light series are available in market and they cost only 100/- rs to 500/- rs. The most popular amongst them is multicolour multifunctional light series with vary small light bulbs having size of rice grain. This series costs 100/- rs to 150/- only. But these are “China-made”. Their durability is a big question.

So here I am presenting how to make such light series at home with few discrete components and number of LEDs. The light series are actually made up of series of small bulbs and they operate directly on AC supply. While I have made a circuit using LEDs connected in parallel and they operate on DC supply. To generate same kind of sparkling multicolour effect I have used self flashing multicolour LEDs that are readily available in market.

So first collect all the required components

· Capacitors – 0.47 K (400 V), 1000 µF (50 V), 0.1 µF

· Resistors – 1 MΩ (0.25 W), 33Ω (1 W), 47Ω (0.25 W)

· Diode bridge (or 4 diodes – 1N4009)

· LM7805

· Multicolour LEDs (15 to 20)

Make a circuit as given below on PCB.

(Check the circuit diagram tab for complete circuit for DIY : Homemade multi colour LED light series)

Circuit Description

The circuit is actually transformer less DC power supply.

· A 400 VAC line capacitor of 0.47 K (C1) is directly connected to 230 VAC line in parallel with 1 MΩ resistor (R2)

· One more 1 W resistor of 33Ω (R1) is also connected directly with line

· AC inputs of diode bridge are connected with AC input in series with resistance R1 and parallel combination of R2 C1

· The output of diode bridge is given to input of voltage regulator IC 7805 through filter capacitor C2 of 1000 µF.

· The output of 7805 IC is filtered through capacitor C3 of 0.1 Ω and given to all LEDs through current limiting resistor R3 of 47Ω. All the LEDs are connected in parallel

Circuit Operation

As I said the circuit is just a DC power supply that generates 5V regulated DC output.

· The R2, C1 parallel combination step downs 230 V AC level and also it limits the current supplied to diode bridge

· Resistor R1 in series with AC supply line also limits the current supplied to diode bridge

· The diode bridge rectifies AC and gives full wave rectified output

· Capacitor C2 filters out this rectified output and generates pulsating DC output

· Finally 7805 will give regulated 5 V DC output from this pulsating DC input

· When this 5 V output is given to all LEDs connected in parallel they will start glowing

· Because all LEDs are self flashing and multicolour it gives nice, amazing, sparkling lightning effect same as light series

The output current of such transformer less power supply is limited. So we can not connect more number of LEDs. Output current of such power supply is 100 to 200 mA. So we can connect 15 to 20 LEDs in parallel. If any one wants to connect more LEDs then instead of 7805 (for 5 V supply) use 7809 or 7812 for 9 V or 12 V supply. In that case increase value of series current limiting resistor R3 to 68Ω or 82Ω.