6THE RAILROAD CROSSING LIGHT
THIS CIRCUIT FLASHES TWO LEDS IN AN ALTERNATING PATTERN.
THE CIRCUIT DIAGRAM
THE PARTS LIST
PART |
VALUE |
DESCRIPTION |
R1, R4 |
470 Ω |
Standard resistor |
R2, R3 |
47 kΩ |
Standard resistor |
Q1, Q2 |
BC547 |
Any general-purpose NPN transistor |
C1, C2 |
10 μF |
Polarized capacitor |
L1, L2 |
|
Standard-output light-emitting diode |
ABOUT THE CIRCUIT
This circuit makes two LEDs flash in an alternating pattern. You can use it for a model railroad crossing, for example, or for eyes on a toy robot.
This is a classic circuit called ...
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