Skip to main content

Reply to "Semaphore and 555 Timer Circuit"

If there is any interest, here are the Diptrace and gerber files for the SN74AC86 version for anyone that wants to try making one of these. This version will operate either Common Anode or Common Cathode traffic lights. CA or CC mode is jumper selectable on the PCB. The files attached include parts lists with Digikey part numbers. I have tested this here and it works well with either CA or CC traffic lights. 

On my test PCBs for the current version posted below, I had some of the parts and screw terminals a little bit too close to a couple of other components. Everything still fit in it's designated spot (some snuggly), but some of the screw terminal IDs were covered after the components were installed. In the files posted here I have tried to adjust all this to allow proper spacing, but I have not yet ordered any new PCBs with these changes. 

As for the costs, the Digikey parts for one PCB add up to $14.90 and $15.77 if you want to add sockets for your IC chips, If your order qualifies for USPS First Class shipping (has to be less than 14 oz.) it will be $4.99. Any sales taxes due would also be added to the total cost. Some items have tariffs, but I think they are included in the prices given. Of course any additional applicable tariffs would also be added to the total cost.

For 5 PCBs at JLCPCB it is $2 plus $5.24 shipping for a total of $7.24. You can also get DHL 2-4 day shipping for $16.81 (5 PCBs = $18.81 total). For 10 PCBs at SEEED it is $4.90 plus $4.17 shipping for a total of $9.07. The PCBs are too large for OSHPark, 3 PCBs were $36.50 for 3 PCBs with free shipping.

4-Way Traffic Signals CA-CC 74AC86 v4D Schematic4-Way Traffic Signals CA-CC 74AC86 v4D BOM4-Way Traffic Signals CA-CC 74AC86 v4D PCB4-Way Traffic Signals CA-CC 74AC86 v4D PCB 3D

Also attached is a PDF file including the above pics for download with the Diptrace files. 

I also have some PCBs for the CD4070 version, identical to the one posted here but using CD4070 ICs instead of the SN74AC86 ICs. This version can run on 9-12 VDC, but have less output current to the traffic lights. This is the circuit I breadboarded for testing as I didn't have the SN74AC86 ICs at the time Stan was designing the circuit for me. These haven't yet been assembled or tested, but I plan to do that soon and see how they work. If there is any interest I can also post those files when done. 

Then there are the higher current output versions using transistors or MOSFETs which also worked well in testing. However, these versions are not easily selectable between Common Anode and Common Cathode. Switching between modes here would require slightly different PCB configurations and would not be all that practical. They would be best when built for one mode or the other, not both. 

Even if no one ever uses the stuff posted here, it's been a lot of fun and a good learning experience for me! And a BIG Thanks to Stan and GRJ for all the help with this!  

Edit: - 09-03-2019 -  There was a mistake in one of the PCB 3D components. It was only a cosmetic thing, but I wanted everything to be correct. It's now been fixed and all the files posted here have been replaced with the corrected versions. 

Attachments

Last edited by rtr12

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
×