This simple railway crossing signal will be especially suitable for people interested in model trains, but will also find its use elsewhere. It is a flasher with two alternating flashing red LEDs using the very popular integrated circuit NE555.
Resistors R1 and R2 together with capacitor C1 determine the frequency that the connection will flip, at output IO1 (pin 3) alternately log.0 and log.1, this causes that only one LED will always be lit. Connect the supply voltage (12V) to the input terminals, the device works from 5V. The power supply of the module is a maximum of 15V.
Printed circuit board:
Placement plan and PCB are at 1:1 300 dpi (How to print a PCB design can be found in the post How to print PCB design). Real size PCB is 28,0 x 26,4 mm.
|LED1, LED2||5mm red|