My Light Diagram

Very simple, versatile modular design No limits to the number of modules used in the ring Circuit diagram using LEDs:                             Circuit diagram using Lamps: Parts: 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) Comments: 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 p...

Description    This device was designed on request; to control the light intensity of four filament lamps (i.e. a ring illuminator) powered by two AA or AAA batteries, for close-up pictures with a digital camera. Obviously it can be used in other ways, at anyone's will.IC1 generates a 150Hz square wave having a variable duty-cycle. When the cursor of P1 is fully rotated towards D1, the output positive pulses appearing at pin 3 of IC1 are very narrow. Bulb LP1, driven by Q1, is off as the voltage across its leads is too low. When the cursor of P1 is rotated towards R2, the output pulses increase in width, reaching their maximum amplitude when the potentiometer is rotated fully clockwise. In this way the bulb reaches its full brightness. Circuit Diagram: Parts: P1 = 470K R1 = 10K R2 = 47K R3 = 1.5K C1 = 22nF-63V C2 = 100uF-25V D1 = 1N4148 D2 = 1N4148 Q1 = BD681 B1 = 2xAA cells in series IC1 = 7555 or TS555CN LP1 = 1.5V 200mA Bulb SW1 = SPST Switch  Notes:  LP1 can be o...