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Ornamental LED Circuit

Here is a simple LED flasher for decoration purpose. The High bright LEDs flashes alternately giving a brilliant colour display. The circuit is a simple Astable multivibrator using two NPN transistors T1 and T2.The circuit works on the principle of charging and discharging of capacitors C1 and C2. Current from the positive of battery flows through first set of LEDs D1-D5 to the collector of T1 through resistor R1.

Resistor R1 limits current through the LEDs to protect them. The current through R1 and LEDs charge capacitor C1. It then discharges through the base of T2 and resistor R4. This gives base current to T2 and it conducts. As a result second set of LEDs D6-D10 lights. As the Capacitor C1 discharges completely, T2 turns off. LEDs D6-D10 also turns off.

The same thing happens in the other side also. This gives alternate flashing of LEDs.Thus the flashing effect is produced through the switching of T1 and T2 by the charge from capacitors.Flashing rate can be changed by changing the value of R3,R4 or C1,C2. If 500K preset is used in the place of R3/R4, flashing rate can be varied.

Ornamental LED Circuit

3 Comments

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  • sanjoy maity

    I want to make a chain of 60 nos violet led .pl tell me the PF value .if I connect 0.47/250v led was damage

  • 48ncj

    de ce se publica scheme neverificate? Incep sa cred ca pe aici publicatiile fiind neveridice nu mai trebuiesc urmarite . Am crezut ca aici posteaza scheme oameni seriosi cu o meserie la baza . Concluzia mea : nimic nu e serios , totul e o cacialma . regret

  • KROKKENOSTER

    These circuits are very dandy!I still remember when they came out ca 1966 I was then an appy and one of my colleagues came and told me about this lamp that operate on D.C. only now I did not argue with him but said that must be something new I only knew of incandescent and neon lamps with neons running A.C. Those days the price was a week’s wages for one! Now the hobbyist has it his/her way and get them for cents! They could be bought in any colour as long as it was red (like model T Fords! only in black and brush painted!)They were dull and you could not see if they were glowing in broad daylight Everyone had its part number and the manufacturer’s name printed on them and were boxed singly!They did not last as long as predicted then the solid state lamp!(Reminds me of C.D’s that were “Guaranteed ” to last 90 years)I now take every guarantee with a truckload of salt! SALES TALK!?

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