Need help making 12v RR lights blink from 120v source

[MN Ben]

I picked a couple of old rail road lights. They are set up 12volt. Currently just a bulb, socket, and wires. These lights are exactly like the ones you currently see at train tracks. I need to make one to sell to pay for the other I want to keep.


I picked the lights at the local iron salvage yard. 4 for about $25, considered mixed metal-  cheap if you ask me. The aluminum old light poles were a different story. They buy aluminum (cans) for about $0.55/lb but sell aluminum for $0.85/lb. so a 9ft light pole, like the fancy ones similar to your main street, ran me about $60, I bought two.

I would like to plug these into the house outlets and have the TWO lights alternately blink, just as they would out in the field.

So, this is where I need some of your help. I am thinking using a doorbell transformer which would get me from 120v to 12v.

Then I would think of using a blinker relay from a vehicle. I have a diagram here if this upload works.

So, I imagine some of you may have done thins or know how do do it. Will this work?

MN Ben

[OperaHouse]

I need to sell some circuits to pay for my internet. Doesn't this need a solar panel?  Search on ebay for alternating relay.  There is one for about $15.   YUCK.....It uses 555's..  If you know what you are doing, use a MC14541.

[ghurd]

"MC14541"?
It only needs a car turn signal relay.

Ben,
If the timing is critical, I make a 12VDC unit for another application with the timing fixed.  Works with 1ma up to about 20A.  Can shoot me an email if you need something like that.
G-

[tanner0441]

Hi
.
A door bell transformer may not have enough current. Look at an old switched mode PSU for a laptop, normally about 12V at 5A, will run more power than a 5 to 15W bell transformer and already DC..

Brian

[MN Ben]

Hi
.
A door bell transformer may not have enough current. Look at an old switched mode PSU for a laptop, normally about 12V at 5A, will run more power than a 5 to 15W bell transformer and already DC..

Brian

Where would I find one of these psu's?

[birdhouse]

this should do it...
http://www.ebay.com/itm/12-Volt-5-Amp-12V-5A-DC-Supply-AC-Power-Adapter-Charger-For-PC-LCD-Monitor-TV-/280797192728?pt=Laptop_Adapters_Chargers&hash=item4160d12218#ht_5022wt_1029

from china, so shipping isn't fast, and who knows on quality.  personally, i've had great results from a few different chinese power supplies...

adam

[Larsmartinxt]

I actually designed one of those for a guy on another forum I'm on



link to thread: http://subaruxt.com/forum/viewtopic.php?f=6&t=11165&start=15&st=0&sk=t&sd=a&hilit=lm555

"MC14541"?
It only needs a car turn signal relay.

Turn signal relays are usually picky about the impedance of the lights you are using so that when there is less load on the relay it switches much faster than normal.

[wooferhound]

can't you just remove the 12v bulbs and replace them with 120v bulbs
or replace the bulb sockets to use 120v bulbs

[OperaHouse]

l've never seen a multi terminal 12V flasher.  Sure they exist but likely expensive.  A two terninal flasher could be on one set of lamps and a relay to invert that for the second.

Years back my new car had three lamp turn lights and had to make that work with trailers combined turn and brake.  I used a relay between turn and brake hot.  That alternated the flashing.

A MC14541 is a neat little timer chip only needing two resistors and a capacitor.  It can do one shot or continuous 50/50 and time up to about a week.  We sold thousands of these and I have boxes of discarded ones.  About 15 years ago they switched to using 8 pin PIC's for most everything.

[MN Ben]

can't you just remove the 12v bulbs and replace them with 120v bulbs
or replace the bulb sockets to use 120v bulbs

I could but I still need/want to make them blink. I remember a Christmas light string I once had used a controllers that could adjust the amount of blink. Christmas is a long ways away, maybe the thrift store has one. I have yet to look at the diagram above.

Ben

[MN Ben]

I actually designed one of those for a guy on another forum I'm on



link to thread: http://subaruxt.com/forum/viewtopic.php?f=6&t=11165&start=15&st=0&sk=t&sd=a&hilit=lm555

"MC14541"?
It only needs a car turn signal relay.

Turn signal relays are usually picky about the impedance of the lights you are using so that when there is less load on the relay it switches much faster than normal.

Hey, that is just what I am looking to do! I will read up on that, but now I must get my but up off the couch.

[jlt]

  google search wigwag flasher. should be able to find one ready made for about 20 dollars.
                                                                                                                                        jlt

[wooferhound]

https://www.google.com/search?q=alternating+flasher&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#q=alternating+flasher&hl=en&client=firefox-a&hs=HMd&rls=org.mozilla:en-US:official&prmd=imvns&source=univ&tbm=shop&tbo=u&sa=X&ei=EfHGT7T-NYWq8ATixtzeCw&ved=0CKUBEK0E&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=fabde5fadd14df5&biw=1174&bih=998

[ghurd]

"Turn signal relays are usually picky about the impedance of the lights you are using so that when there is less load on the relay it switches much faster than normal."

Thats why I said mine works with 1ma up to about 20A, and its less than $20 too! 
G-