Semaphore and 555 Timer Circuit

Tom, my projects are normally limited to things I can't buy as I've also found that the prices for some of this stuff is less than I can do it for.

rtr12 posted:

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However, I think Stan had the additional output loads in mond with the transistor and MOSFET versions above. Those are not CA - CC interchangeable by jumper selection, they would need separate PCBs for CA or CC. I am not sure of how much extra load they can handle, I'll have to look that up on the data sheets. (I don't know (or completely understand) all the components like Stan and GRJ do.) 

If the application is to control track power, I'd go with a 10 Amp relay module...less than $1 per relay with free shipping from Asia.  So, for example, 6 of the 8 relays in this 8-channel relay module could switch 10 Amps to R, Y, G or each direction.

These relays have buffers on the inputs so can fire at about 1 mA which can be supplied even by the 4070B version of your controller board.  I notice the suggested other controller module can drive just under 1 Amp per output.  Not clear if this would be enough to switch track power for block or traffic control.

As I understand it, the other controller module can only drive DC loads whereas the relay module can switch AC...again, if the application is to control track voltage.

stan2004 posted:

rtr12 posted:

...

However, I think Stan had the additional output loads in mond with the transistor and MOSFET versions above. Those are not CA - CC interchangeable by jumper selection, they would need separate PCBs for CA or CC. I am not sure of how much extra load they can handle, I'll have to look that up on the data sheets. (I don't know (or completely understand) all the components like Stan and GRJ do.) 

If the application is to control track power, I'd go with a 10 Amp relay module...less than $1 per relay with free shipping from Asia.  So, for example, 6 of the 8 relays in this 8-channel relay module could switch 10 Amps to R, Y, G or each direction.

These relays have buffers on the inputs so can fire at about 1 mA which can be supplied even by the 4070B version of your controller board.  I notice the suggested other controller module can drive just under 1 Amp per output.  Not clear if this would be enough to switch track power for block or traffic control.

As I understand it, the other controller module can only drive DC loads whereas the relay module can switch AC...again, if the application is to control track voltage.

 

Stan is right as usual, these relay modules are great.  They can be used to control your block loads, as isolators, inverters, drivers, etc.  They are available in a number of configurations and they are inexpensive.  The “other controller” is only DC output.  I liked it in part because I could use it to trigger these relay modules and I didn’t have to worry about fanout if Murphy made my design change.

GRJ, Yes, I seem to be finding that out too. I already knew it was true for buck converters, reelays (as in Stan's post) and some other stuff, but the $15.99 traffic controller is a new one on me. The cheap ready made electronics also take all the fun out of learning about all this. 

Stan, I did not realize the low 1mA activation of those relays. That is a very low power requirement. It's also amazing the prices they can sell these for!  I have some older ones here and even some in use on the layout for switching power to spurs due to the problems I had with my manual switches (automotive type with LEDs). I also have some single and double relay modules that are very similar. I don't think I would try the new module I ordered for switching track power without using the relays.

Any ideas how they got to the nearly 1 amp current handling? I want to examine that module and see if I might learn something, part of the reason for the order. Probably won't learn much from it, but you never know. It does sound like a nifty gadget to have on hand and if you would like anything tested with it, just let me know and I'll try. 

Shorling, Thanks and good luck with your project as well. I noticed they had some 'kits' and/or 'assembled' modules where the kit was cheaper, but not a lot less. I still need to take a closer look at all of their offerings. It's like 98 deg. here today with humidity to match, good time for doing that this afternoon.

Tom, the relay board has an external power supply requirement, so the 1ma is simply the drive needed to trigger the on-board circuit.

rtr12 posted:

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Any ideas how they got to the nearly 1 amp current handling? I want to examine that module and see if I might learn something, part of the reason for the order. 

It looks like there are 6 FET devices on their board in the so-called SOT-89 surface mount package.  There are hundreds of choices that can handle several Amps of current (DC) for less than 50 cents each.  I previously suggested the 2N7000 FET, albeit with less current handling capability, because it has been around forever and is readily available for a nickel or so.

GRJ, thanks for the clarification. I didn't think of that part...coming from the external power. Was only thinking about the requirement to activate the relay itself. I still have some trouble visualizing these things. Having one in hand is much better, it helps anyway. I warned you the learning part was still on going... 

Stan, sounds like the same as what we (well you, then feeding me the ideas and how-to's that is) have been working on here with the MOSFETs and transistors. I was picturing the ready made module as being something different for some reason? I'm now thinking that it is similar to the stuff you have been helping me with, but probably using GRJ's PIC chip or other microprocessor for the ease and variety of mode selection. And if I am reading the description correctly they even have the jumpers for CA or CC operation built in. I'm looking forward to seeing this thing when it arrives.

Did you by chance see the one that works on 120vac and can handle 500 watts? They had some interesting stuff there (to me anyway). Prices seemed reasonable. I think I even saw 'made in USA' on some of them. They also have an ebay store, slightly higher prices, but most if not all had free shipping which made them actually a little less in final cost. I saw some LED flasher type modules that appeared to be using ICs, possibly similar to what you have been helping me with here. I'm tempted to order one of those as well, just for comparison. But the PIC lessons might now have preference. 

I'd love to find a place that would assemble modules in the US for anything approaching the Chinese prices, I'd much rather have my stuff done here.

That would be nice. I was really surprised to see that on the module I was studying there, especially with their pricing. Wonder where they get them or maybe they do it themselves?

Hard to say, but I know I can't get any decent pricing for stuff made here!

rtr12 posted:

...And if I am reading the description correctly they even have the jumpers for CA or CC operation built in. 

Not sure that module has both CA vs. CC mode built-in.  One bullet (shown above) suggests the LED output mode is "Common anode".  There are two 2-pin shunts with a resistor next to it.  My guess is that resistor is in series with the common anode.  Installing the shunt shorts the resistor thereby passing full voltage to the lamps.  To use LEDs, remove the shunt and the resistor limits current to LEDs.   "Common anode" suggests those FETs are of the N-channel ilk.

rtr12 posted:

...Did you by chance see the one that works on 120vac and can handle 500 watts?

From the photo, I'm guessing they are using 3 triacs (one per color) preceded by 3 opto-isolators to switch AC quietly (vs. clicking relays).  If you needed to do this, attach a solid-state-relay (SSR) module to your output.  An SSR is essentially an integrated opto-isolator and triac.  Note the modules have screw-terminals on input and output so you don't need to fire up the soldering iron.  Perhaps not quite as economical as the $1/relay modules but they would be quiet.  You'd have to select an SSR with suitable power handling capability.

GRJ, they would have to be getting them made pretty cheap to be able to sell at such low prices, unless they are making little or no profit and doing this just for fun like I am (I think that's a long shot). 

Stan, I think you are exactly right about the CC-CA selection, I was not reading it correctly. Your description makes more sense too. As for the 120vac module, I won't be using it. I much prefer the low voltage stuff, less chance of electrocuting myself!  I do appreciate you explaining the way everything operates and the components used. I still find all this interesting and like to learn about the different methods for doing these things. I can see where a circuit designer might even have 'too many' options. I could see myself getting stuck in this area. The solid state relays are something I might investigate too, I like the 'quiet' part and they would be interesting to experiment with and I don't have any so more stuff to order. 

To add even more to this... I just got an email from We_Honest including one of their traffic light controllers. Costs more than the one above ($24.99), but does some different things. I saw some of their items when I ordered my traffic lights, but I missed this one " 1 x Model Railroad 4-ways traffic signal light controller simulator 4 directions " (for searching). Also they apparently have a traffic signal with additional 'red & green' lights for pedestrians, along with the regular signals. Missed that before too. These things seem to be popping up all over the place!   

stan2004 posted:

Moot at this point if using screw-terminal connectors on the PCB, but that could be the Molex mini-SPOX connector:

If this is indeed the correct connector system, here's the 4-pin PCB-side vertical header from DigiKey.

I bring it up because it reminded me of another DIY PCB hack.  Note the SPOX is a 2.5mm (0.098") pitch while many connectors are 2.54mm (0.1") pitch.  So if you do the math on the connector pin diameters and PCB holes size, you can easily install either a 2.5mm OR a 2.54mm connector for short connectors like the 4-pin used in the traffic signal.  Some free-ware/share-ware PCB layout program may not have a library of 2.5mm footprints and if not used to creating new components, it can be expedient to use an existing 2.54mm component which every layout program has.

 Just for the FYI of it all and future reference, I finally got around to ordering and received these from Digikey today. I got both the male and female connectors (and terminals - still untested). The 'SPOX' connectors easily fit themselves with just a slight 'push - pull' to connect or un-connect them. The MTH plugs fit the Spox headers, but are quite snug and it takes some effort to get them apart. With the MTH to MTH connectors the 'push - pull' is snug, but much easier as the matching SPOX connectors.

Oh my, I think I really butchered that description, hope you get the idea and it is not too confusing. To sum it up, these will work with the MTH headers, but they are a very snug and tight fit that isn't as easy to disconnect as the MTH factory stuff.

Edit: You probably already knew this, but... After careful examination of the MTH connector with a magnifying glass, it had ' 5264 4 DL 18 ' in raised characters molded into the connector. Each set of characters was on a separate line, not consecutive as I have here. Doing a search at Digikey '5264' took me right to the SPOX connectors you found above. I got nothing using a couple of different combinations of the other characters in the searches. 

Update: The PicKit 4 and some PIC chips have arrived (the ones GRJ listed earlier). Time to get busy and figure out how this stuff works.

The CA-CC version of the signal controller has been breadboarded and is all working just as Stan said it would. I ordered some PCBs for that version from JLCPCB. 

The Galak traffic signal controller seems to be in limbo between Galak and the USPS. USPS tracking says label created July 26th, USPS awaiting item. The shipping notice said 3-5 days to arrive (from the 26th). They were a US supplier, it was ordered on July 18th. Guess tomorrow will be a good time to check on that one and see where/why it has disappeared. I have been looking forward to trying that one.

I had a US seller send me something that ended up in limbo, never did get it.  They finally shipped another one.  When it was at the local USPS location for ten days, I said enough is enough, send me the item or give me my money back!

I emailed them earlier, no reply so far. I might just follow your example if they don't reply with a correct solution. Thank goodness for Paypal!

Success on the Galak traffic signal controller, it's on the way. They were out of them, but are now restocked. 

The PCBs for Stan's suggested transistor and MOSFET versions both work quite well. These are both very nice set ups! Still waiting on the combination CA-CC PCBs from JLC, I got sidetracked and procrastinated on ordering these. 

The dual mode (CA-CC) traffic light controller PCBs arrived yesterday. Haven't had time to assemble anything, maybe this coming week. There are some errors in the PCB labeling, but the circuitry seems to be correct. When checked with a DMM everything seems to go to the right place.

I messed up while fiddling back and forth with the 4070 and 74AC86 ICs, forgot to change some resistor values and voltage labeling in the silk screens. Not a big deal, that is, unless I follow my own labeling. The drawings have been corrected and I plan to follow them instead.  PCBs will only be used here for testing and experimenting. They will never escape the highly secured and secluded electronics laboratory constructed of 8" thick reinforced concrete walls! 

I have one of those highly secured concrete walled labs too, but some fool put a window and door at one end.

Actually, I do have one egress window, but the lab is on the opposite side and back behind the stairway. Can't be seen from the window. I don't have one, but the door would sure be handy for getting things in and out.

Well, my door and window are at the other end of my shop as well, but I can see them if I turn around.

I do have a Window next to my computer desk and workbench.

However, if I were foolish enough to try to exit there, that concrete wall would be a major impediment!

Yours is much nicer looking. The natural light is nice too and the layout is also looking good in there. Your work area is much more organized and clean looking too. I seem to have an endless benchtop full of stuff with no allocated space for it. By the time space is allocated for what's there, another pile has built up with no place to go...infinite pile! 

Everything here is unfinished basement, which I actually wanted. That is, until I see others with finished basements and I start thinking about finishing mine. The thought soon passes when I start thinking about having to move everything to make room to do the finishing. 

From your pictures, I think I just figured out one problem I have here. Workbenches are all multi-purpose or at least trying to be. I need to make them more specialized by craft/project (or what's being done at each one). 

Tom,

I actually have a couple more benches/tables as well.  They're used mostly as staging areas when I have a bunch of stuff in process.

You didn't mention my spiffy concrete sunset.

That sunset window was a nice touch, good idea for some added 'natural' lighting. I did like that idea there. Your staging tables even look pretty organized and cleared of massive piles! 

I have a couple of tables as well, but they all have their own pile problems right now. They're pretty small though, I need some bigger ones! Maybe a couple of those fold up 6 footers would help? 

I just can't seem to get completely caught up and everything situated after moving a few years ago. I'm just about to get there when someone leaves more of these electronic gizmos in the mailbox or on the front porch... 

There are around 20+ locomotives stuffed in various corners in process of being upgraded or repaired, I just don't keep them all on the bench!

I don't know how you keep track of all this stuff? I could do it when I was younger, now not so much. I have to go back and re-read the things you and Stan post to help me out with projects, at times I somehow manage to get that stuff all mixed up. 

Good thing I am not doing those repairs, customers would probably be receiving 'Frankenstein' engines back after I got the parts all mixed up! I'm sure you have a pretty good system of keeping track items in for repairs and upgrades.

I spend a lot of time thinking...

"Sometimes I sits and thinks, and sometimes I just sits...”  — A. A. Milne  

In an elementary school I was working in many years ago, there was a poster of a Chimpanzee in deep thought with this caption in one of the classrooms. Been one of my favorites ever since. Some elementary school teachers have quite a sense of humor. 

(Picture would have said it much better, didn't post due to recent copyright stuff...but Google finds it.) 

We have a little statue of an ape holding a skull and looking at it like he's in deep thought, does that count?

Sounds like it would surely count! The quote would certainly fit that one too.  Should have looked this up before, but here's a link to the chimp poster

I should have looked for this poster and bought it years ago when I first saw it, would be perfect for the secluded laboratory! 

Finally got around to assembling one of the dual mode CA-CC PCBs using the 74AC86 ICs. So far it is a fail, nothing works on the traffic light outputs in either CA or CC mode.  I can't seem to find anything wrong in the wiring traces on the PCB or in the schematic? 

One thing I found odd: there is only about 1.1 volts on the 4017's VDD pin when the PCB is powered up. When I remove the 4017 from it's socket and power the PCB the VDD pin (on the socket only) has 5 VDC where the 4017's VDD pin should be. 

I've probably goofed up something, but what?  Back to 'sits and thinks' at the work bench...

Well, the 1.1 volts is a pretty large clue, are you sure nothing is in backwards?  Could the socket be in the wrong orientation on the PCB?

The 1.1 volts is what I was thinking about too, but I am not sure what is drawing it down so low? I thought maybe the 5 volts was too low for the 4017, but the data sheet says it works on 3 to 15 volts. Nothing seemed obvious or to be out of place on previous checking, but I am re-checking it all now. 

The 555 seems to be working as the PCB's led is blinking and adjustable with the trimmer pot.

When I got the PCBs a few days ago I rang out most of the traces on the PCB and they matched the schematic. The only thing  I changed were the resistors for the traffic lights themselves, from 470 to 220 ohms, since the 74AC86's can only take 5 volts. 

What's powering the board?  Are you feeding it DC from a decent sized power supply?  I'd see if the CD4017 is getting hot when it's powered, something is very wrong!  Is this still the schematic you're working from?  Do any of the chips get hot?  How about other components?

I'm using a DC power supply, 30 VDC 5 Amp from Banggood powered by an external power supply that was listed with this item back when I got it. It was more than their minimum recommendations to get the 30 volts and 5 amps out of it, I believe I upsized it one size to be sure.

Yes, basically the same schematic except I changed the 470 ohm resistors to 220 ohm and made some cosmetic adjustments for neatness. I'll attach the most current one with the resistor value changes just to be sure. I didn't catch the resistor value errors or the suggested power supply input voltage until I got the PCBs back.

This was all working on a breadboard using the same power supply, but with a 9 or 12 volt supply voltage. I was using the CD4070 ICs instead of the 74AC86s because I had to order those and had the 4070s.

Here's the updated and latest.

I rechecked it all again and it still appears to be correct, I must be missing something? Even tried it with the 74AC86s removed, still got 1.18 volts on the 4017's VDD pin, but get 5 volts (full supply) on the VDD socket with the 4017 removed. I'm going to get out a new 4017 and try that later tonight or in the AM, was wondering if maybe something was wrong with the IC?. 

Did you perhaps leave the current limit set too low?  From the spec sheet...

Its adjustable output current range is 0-5.000A, step by 0.001A.

I had it set to 0.100 amps, for safety, thinking that would be sufficient. I was only trying one traffic light for testing. But even with no output lights connected it gives the same 1.18 volts on VDD of the 4017.

Guess I could try turning it up to half an amp or even an amp.

That seems to be a fairly nice power supply, got their nice aluminum custom case for it also.

More current tends to localize what is drawing all the current.

Wife has me tied up short today.  I'll crank up the current and go for smoke later this afternoon.

It's a mystery, but something is obviously sucking down current if it's limiting at 100ma.