Basic Electronic Assistance Requested - Start Tree

Drag racing style light trees
Post Reply
rfryar
Apprentice
Apprentice
Posts: 5
Joined: Fri Jan 27, 2012 12:56 pm
Location: Cottage Grove, MN

Basic Electronic Assistance Requested - Start Tree

Post by rfryar »

Hello, I am new to this forum and it has been a good resource for parts, etc.

I have started making my own start tree based off a 555 Timer and a 8021 Decay Counter. I have it prototyped out using leds and a "remote" that also contains leds.

My problem is that I want to replace the leds on the "control" box with larger lights. So I searched and found a really cheap 8 channel relay circuit:
http://arduino-direct.com/sunshop/index ... tail&p=156

However I am having a bit of trouble. The relay circuit triggers on LOW and the 8021 outputs are always low. They switch to high and the LEDs light up. However I am a electronic novice and do not know the best approach to "block" the LOW so that only when HIGH will the relay trigger on.

You can see the prototype video here:

https://youtu.be/xleBIYmQz-U

I am sure it is something simple, but I am pulling my hair out currently.

Thanks,

Rick
User avatar
Stan Pope
Pine Head Legend
Pine Head Legend
Posts: 6856
Joined: Sat Jul 05, 2003 7:01 pm
Location: Morton, Illinois
Contact:

Re: Basic Electronic Assistance Requested - Start Tree

Post by Stan Pope »

The function you are looking for is "invertor". IIRC, they come in IC's @ 6 per 14 pin IC. You can perform the same function with a NOR or NAND gate IC which typically come as 4 per. So that would be 2 Hex Invertors or 2 Quad NOR or 2 Quad NAND IC's. (If you use NOR or NAND gates, look at the truth table to tell how to hold the 2nd input to each gate so that it functions as an invertor... it's been too many years for me to remember!)
Stan
"If it's not for the boys, it's for the birds!"
rfryar
Apprentice
Apprentice
Posts: 5
Joined: Fri Jan 27, 2012 12:56 pm
Location: Cottage Grove, MN

Re: Basic Electronic Assistance Requested - Start Tree

Post by rfryar »

Stan Pope wrote:The function you are looking for is "invertor".
Thanks, I have an invertor on order from Mouser. Thanks for pointing me in the right direction, will update this when I get the parts and if I get everything working!

Rick
dna1990
Master Pine Head
Master Pine Head
Posts: 360
Joined: Wed Jan 09, 2008 8:16 pm
Location: Houston, TX

Re: Basic Electronic Assistance Requested - Start Tree

Post by dna1990 »

I am not positive, but aren't the relays on that board have both NO (normally open) and NC (normally closed) connections? In a pinch and depending maybe on the type of light you are working with, you could keep the LOWs from the controller - they would have each relay "on", but hook up you output to the NC side. Of course in this application, the relays would be "on" for much longer than they are ever off...so getting the NANDs in there is still preferred.
rfryar
Apprentice
Apprentice
Posts: 5
Joined: Fri Jan 27, 2012 12:56 pm
Location: Cottage Grove, MN

Re: Basic Electronic Assistance Requested - Start Tree

Post by rfryar »

dna1990 wrote:I am not positive, but aren't the relays on that board have both NO (normally open) and NC (normally closed) connections?


I tried that first but for some reason it never really turns the relay off. The manufacturer of the board suggested perhaps using a separate 5 volt line would allow it to work in this fashion. Since I have the inverter ICs on order I will wait to mess with this again when it arrives.

I will let you know if I get this working as planned. Oh since I had to order the ICs I also ordered a solenoid to pull the start gate open. I will use another relay to trigger that at the end of the light cycle. :)

Thanks again,

Rick
rfryar
Apprentice
Apprentice
Posts: 5
Joined: Fri Jan 27, 2012 12:56 pm
Location: Cottage Grove, MN

Re: Basic Electronic Assistance Requested - Start Tree

Post by rfryar »

The start tree is completed now. I took a video and pictures before painting, but essentially here are the completed photos.

This is the big AC bulbs
Image

This is the "remote" control that the scouts use to trigger the start of the race. The remote also has LEDs on it.
Image

And a quick picture of my project box, there are a few connectors. The light tree has one RJ-45 plug that goes into the control unit, one AC power cord, and one Audio jack that will fire the solenoid. The control box has another RJ-45 plug that goes to the remote control. This allows the remote to be run down to the end of the track.
Image

Finally the video of it:

https://youtu.be/ucAVDf_WE94

Its first use will be in early March. Hope the scouts enjoy it!

Rick
User avatar
ciodude
Master Pine Head
Master Pine Head
Posts: 283
Joined: Wed Apr 04, 2007 1:34 pm
Location: Charleston, WV

Re: Basic Electronic Assistance Requested - Start Tree

Post by ciodude »

A very neat project. It looks great! Thanks for sharing.
Post Reply