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:

...

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.

Untitled

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.

 

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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.

Untitled

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.

Steve

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:

...

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. 

traffic_light_large

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.

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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?

rtr12 posted:

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

dual shunt

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?

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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.

ssr 

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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:

molex spox

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!

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. 

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