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LEDs or Lamps Sequencer

Very simple, versatile modular design

No limits to the number of modules used in the ring

Circuit diagram using LEDs:

LEDs Sequencer

Circuit diagram using Lamps:

Lamps Sequencer


R1______________1K5  1/4W Resistor
R2____________680R   1/4W Resistor (Optional, see text)

C1_____________47µF   25V Electrolytic Capacitor

D1_____________LED  any type

Q1___________BC337    45V 800mA NPN Transistor

P1_____________SPST Pushbutton

LP1____________Filament Lamp 12 or 24V (See text)


The purpose of this circuit was to create a ring in which LEDs or Lamps illuminate sequentially. Its main feature is a high versatility: you can build a loop containing any number of LEDs or Lamps, as each illuminating device has its own small circuit.
The diagrams show three-stage circuits for simplicity: you can add an unlimited number of stages (shown in dashed boxes), provided the last stage output was returned to the first stage input, as shown.
P1 pushbutton purpose is to allow a sure start of the sequence at power-on but, when a high number of stages is used, it also allows illumination of more than one LED or Lamp at a time, e.g. one device illuminated and three out and so on.
After power-on, P1 should be held closed until only the LED or Lamp related to the module to which the pushbutton is connected remains steady illuminated. When P1 is released the sequencer starts: if P1 is pushed briefly after the sequence is started, several types of sequence can be obtained, depending from the total number of stages.


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