Relays for Track Power using AIU

Well, there's good news and bad news

Resistor is correct (if that's brown-black-green-gold stripes).

Capacitor is incorrect.  Photo shows a 1nF (1 nanoFarad) capacitor which is 1000 times small than a 1uF (1 microFarad) capacitor.  Yes, in retrospect I suppose it's a bit confusing to use "u" to abbreviate "micro" - it's a Greek letter thing.   If you're buying this off a rack or whatever at a parts store, the correct label would be as shown.  Even though the correct capacitor value is 1000 times larger, the physical part size will be about the same and should cost about the same.

Ok , back to the store. Yep, it’s Greek to me.

Stan, I thought that you might get a laugh out of this.....

Fast, Cheap, Good. You get to choose 2.  

I thought you were just buying at a local store.  Anyway, here's a US seller in your neck of the woods. 19 cents vs. 5 cents each.  If you ordered today I wonder if they'd beat the ones from China! 

My experience with those shipping advisories is I'll get the item about 1 week after "clearing customs" in the US. 

The estimated date of delivery is 5/21!

Ordered... DOD 5/18

the race is on!

The American store lost by one day which is t bad considered that I ordered from the Chinese in the middle of April

The board is built and (probably did something wrong) it doesn’t function. The first siding turned on, triggers the remote commander. Turning on the second does nothing. In the reverse order, first come first served.

Following, are photos of the board that I put together. Underside is first , top side is last. I ran a wire from the first two inputs on the relay board(sidings 1 snd 2)to the inputs on my concoction. The diode connects to the resistor with the capacitor framing the resistor. The other end of the resistor led to the output connection which is wired to the trigger port of the FR01. First siding powered triggers the FR01 which triggers the MTH remote. Powering on the 2nd siding does nothing.

Any thoughts?

From what I can see, your wiring looks OK.

So I just wired up 3 "channels".  Each channel (I'll call them A,B,C) is a diode (1N4003) followed by the capacitor (1uF)-resistor (1M) pair going into the FRM01 CH1 trigger terminal.  FRM01 is set to Mode --02 as your photo indicates.  I set the T1 delay to 4 seconds.

I applied 12V to A. FRM01 relay clicks on for 4 seconds.  After relay clicks off, I applied 12V to B (with A still "on") and FRM01 re-triggers for another 4 seconds.  After relay clicks off, I then applied 12V to C (with A and B still "on") and FRM01 re-triggers for another 4 seconds.

I also tried it with the power supply set to 10V DC and 14V DC to rule out any voltage sensitivity in case your 12V supply is not exactly 12V.  Same result.

But I hear what you're saying - you're seeing the circuit fail to perform when just 1 channel is already "on".  I'm not sure what to suggest!  

-----------------------------

Just to be clear, this simple circuit does have its limitations.  After maybe 5 channels already "on", additional channels may not re-trigger the FRM01.  I didn't think this would be a practical requirement - though handling an arbitrarily large number of "on" channels can certainly be done with more parts.   While I can't imagine why this would be different, confirm the two resistors on the FRM01 next to the CH1 trigger input screw-terminal are as shown - marked 203 and 103 as shown (that means 20K and 10K Ohms respectively).

Do you have the capacitor soldered at each end of the resistor ? Or are they connected in a series ( one after another)? I just looked at the FRM01 and the two chip numbers are identical. Do you connect outputs into one common wire going to the FRM01?

For fun, I took the lead to the CH1 and touched it to different points in the diode-capacitor/resistor setup and found that no power was getting beyond the capacitor/resistor pair.

strange.

George, let's deal with this offline.  Send me an email.

Nowhere in the manuals for the Accessory Interface Unit do they have a normal switch schematic showing the Accessory switch positions when the DCS system shows them on or off.  Is 2 normally closed when you tell that accessory to be OFF?  It never clearly says; you have to deduce that from their wiring examples.  Also, do all of those revert to off when powered down and then stay there, or do they return to their last state when you power the system back on?  It makes a difference in planning!  This is basic info that should be in the manuals rather than require us to figure the answers out by experience!

I've been working on a pictorial schematic of my planned terminal strips and wiring for track power and switched track power.  Since I plan to have the various switched tracks and sidings normally powered on, I have it wired so the tracks are connected to the normally closed contacts on the relays, so to power the track OFF, you must energize its associated relay.  This should reduce the time the relays have power to their coils.  It depends on how I actually run the trains in the end.  It's easy enough to change from the normally closed to the normally open contacts on the relays, in any event; just move the spade connector from one terminal to the other.  I will use the same 12VDC power supply that I had on hand for the Tortoise switches and to power the TIU.

I am using the relays below from Allied Electronics; $1.25 each.

kbaybob posted:

Nowhere in the manuals for the Accessory Interface Unit do they have a normal switch schematic showing the Accessory switch positions when the DCS system shows them on or off.  Is 2 normally closed when you tell that accessory to be OFF?  It never clearly says; you have to deduce that from their wiring examples.  Also, do all of those revert to off when powered down and then stay there, or do they return to their last state when you power the system back on? 

Above from AIU manual.  ACC relays are SPDT.  2 is NC.  Relays revert to OFF between operating sessions (no memory of last position).  

THANK YOU, Stan2004!  I hoped someone would quickly show me the error of my ways and remind me of my oft stated aphorism; RFM!  I appreciate the prompt feedback that shows I was headed in the right direction in my planning.

Bob

I used Stan's original setup and agree with the comment regarding the constant clicking of the timer module. It was that or having to turn off the whisker or roundhouse stall to turn the next one on. Before the new and improved timer schematic came along I set out in a different direction. It involves more components but still accomplished the same result. I have nine roundhouse stalls and seven whisker tracks surrounding my turntable. I used two 8 bank relay modules (power to the stall/whisker) and 16 555 timer relays to trigger the WD signal. Works great.