I have made model rail level crossing lights which uses reed switch positioned on track to sense magnetic field of coming train and then LEDs are flashed.

It uses three 555 timer - monostable, bistable and astable circuit.

Now, I want gate or barrier at railway crossing to automatically drop when train comes and automatically lift up when the train leaves.

Any idea how to implement this ??

 

I'd suggest using an RC Servo. By varing the pulse width to the motor, you can control the angle that it rotates. See Here - http://www.geocities.com/bourbonstre...rvobasics.html
You may have to add some additional circuitry to get the right look out of it, but its alot easier to control than a regular motor. It should be plenty powerfull enough for this application too.


Hope that helps.

__________________
Jeff
To the optimist, the glass is half full.
To the pessimist, the glass is half empty.
To the engineer, the glass is twice as big as it needs to be.

 

I took model railway crossing project by this link www.kpsec.freeuk.com.
sir, i received your suggestion by servo motor which works on milliseconds.
but we want to up and down the barrier in few seconds.first of all ,when the yellow led be on then we want to down the barrier after the yellow led off,which off after 3:54sec.and we want to up the barrier after about 15seconds.please reply soon auto barrier designing with servo motor circuit.

thanks.

 

Since a servo is a DC motor with positional feedback you could raise and lower a model barrier at any speed you like, from seconds to minutes, hours, days, weeks. The servo is CONTROLLED by a pulse that is 1ms to 2ms wide, it needs to be refreshed every 20ms or so.
You'll probably need a microcontroller to run it the way you described.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

with out servo motor,we want to another idea to make automatic railway barrier by using pressure transduser,acustic transducer or sound viration system on low cost.

 

Toy trains don't offer much pressure on the track, magnetic or optical sensors are more common.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

to make automatic railway barrier , how used magnetic or optical sensors?
please tell me with circuit