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walk/don’t walk sign

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=133618
Printed Date: May 04, 2024 at 3:02 PM


Topic: walk/don’t walk sign

Posted By: yitz0550
Subject: walk/don’t walk sign
Date Posted: February 18, 2013 at 3:34 PM

This question has been asked a couple of years ago but that topic has since been closed and doesn't have a satisfactory answer... so here I go with the question again....

I have a Walk/Don't walk sign. I will have them run each side on 120vac power. I could have them on 12vdc coil relays and a transformer, so 12vdc parts is perfect.

I would like the "walk" to be on for about a minute, followed by the "don't walk" to flash at a slow rate for about 10 seconds then solid for about a minute.

Youtube clip example

Any help would be greatly appreciated. Thanks in advance!!



Replies:

Posted By: howie ll
Date Posted: February 18, 2013 at 3:55 PM
Velleman do a timer relay, 12VDC, start stop, start stop, something like Mk 111.
Google it.
All you need.

-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.




Posted By: oldspark
Date Posted: February 18, 2013 at 6:24 PM
Plus an inverter to get the 120VAC unless you convert the lights to 12V.




Posted By: yitz0550
Date Posted: February 18, 2013 at 6:40 PM
howie ll wrote:

Velleman do a timer relay, 12VDC, start stop, start stop, something like Mk 111.
Google it.
All you need.


This will take care of the flashing of the "don't walk", but I need more functions. I need that flashing to last only about 10 seconds then automatically go solid for a minute then have the other light, the "walk", stay solid for a minute. Then it needs to repeat itself over and over...


oldspark wrote:

Plus an inverter to get the 120VAC unless you convert the lights to 12V.


Transformer....




Posted By: oldspark
Date Posted: February 18, 2013 at 7:09 PM
yitz0550 wrote:

Transformer....

So what (multi-)vibrator are you using to drive the transformer?
Or are you using 12V AC?




Posted By: howie ll
Date Posted: February 19, 2013 at 2:34 AM
Now you've got me confused, Peter's right you will need an invertor NOT a transformer if you run the whole shebang off 12VDC.
OP, that Velleman unit has adjustable pre-sets, no problem with 10secs. on minute off, or vice versa the built in output relay is a change-over type.
I've given you the info look up the spec, whole idea is dead easy.
And why not make life far simpler with less current draw and use low voltage LED lighting.

-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.




Posted By: oldspark
Date Posted: February 19, 2013 at 4:51 AM
Yeah, I like the voltage conversion of the lights.
I don't like providing advice for the switching 120VAC with relays etc due to the hazards and Regulations involved. (If suggested relays or kits are NOT 120VAC etc rated, then they can switch relays that are. But that may still require licensed people.)


If those lights are LEDs, then chances are that they are NOT high voltage strings.
For reliability (and other reasons), their power is usually converted to DC, and much lower than mains (AC wall socket) voltages.
But otherwise, higher voltage AC & DC LED strings can be modified to smaller strings suited to 12V etc (typically 3-6 series LEDs with one resistor per string, and each string then connected in parallel).

The same would apply to bulbs - they are probably low voltage, but their "conversion" can be messier...

The beauty of the voltage conversion is not only safety, but also increased efficiency since inverters can be omitted.

But if 120VAC is to be used, then consider GND switching of the lamps. But note that the relays etc still need to be rated for 120VAC and that a "turned off" relay has 120VAC on one of its terminals.




Posted By: yitz0550
Date Posted: February 19, 2013 at 7:05 AM
Hi guys. Sorry for making this complicated, it really isn't....

The lights are enclosed, all that's coming out is 3 wires from each fixture which are 120vac, line, neutral and ground. The fixtures are sealed and water-proof, I'm not in the mood of changing that. This is going to be on a display in a kids' school, where 120 is readilyable, no need for inverters. Also, I'm a qualified electrician so 120 is not an issue, it will all be in a 100% legal and safe enclosure.

Now back to the question. Let's forget for a minute what the load will be. In my case it will be a 2 relays. Let's call them relay "A" and relay "B".

This is the sequence I want to get:

Relay "A" flashing on-off-on-off-on-off.... For about 10 seconds, while relay "B" stays off.

Part 2: Relay "A" steady on for about 60 seconds, while relay "B" is still off.

Part 3: Relay "A" off, and relay "B" on, for about 60 seconds.

Repeat the cycle....




Posted By: howie ll
Date Posted: February 19, 2013 at 7:08 AM
Which is exactly what the Mk111 will do.

-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.




Posted By: yitz0550
Date Posted: February 19, 2013 at 7:14 AM
I read up and download info on the mk111. If I understood it all correctly, this will control only 1 output. It CAN control 2 outputs but output #2 will always be the opposite state of output #1. So when my relay "A" well be flashing on-off-on-off my relay "B" will also be flashing but off-on-off-on. Correct me if I'm wrong.




Posted By: howie ll
Date Posted: February 19, 2013 at 10:06 AM
The on-board relay is a SPCO you have 3 terminals, NC, NO and common.
When it's triggered the NO completes the circuit.
When timer shuts down, the NC is connected. That simple.

-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.





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