DZ-1000 Control w/ single button

From their website

As I understand it, you're trying to replace the 2 switches labeled "SB" and replace LED3 and LED4 with a single bi-color LED.

By bi-polar LED do you mean to restrict the LED to be of the 2-terminal style?   Apply one polarity you get one color, apply reverse polarity you get other color. 

Stan, 

I can go either way with the LED, i have both 2 lead and 3 lead type bi-polar LED. Just looking for a simple solution. I thought about doing a relay trigger to throw the switch machines but just wondered if there was a different method to the madness. 

I used SPDT momentary toggles and added led's to indicate position.  You still can not see the led's on the DZ1000's - so I am adding two position dwarf signals, homemade.  Looking great , pictures later.

Go to the Z-stuff web site and find the diagram on how to install the toggles.

bruce

christhetrainguy09 posted:

...I can go either way with the LED, i have both 2 lead and 3 lead type bi-polar LED. Just looking for a simple solution. I thought about doing a relay trigger to throw the switch machines but just wondered if there was a different method to the madness. 

So here's what I see as the "problem" if you're after a simple solution.

If you look at the red and green LEDs in their controller, you do NOT have a common anode or common cathode.  I am not aware of any 3-terminal bi-color LEDs where the cathode is connected to the anode.  You either have common anode or common cathode as illustrated above.  So if you only want to, in essence, drill a single hole in your panel to mount a bi-color LED, I don't think you can do it with a easy-to-find part. 

Seems to me, way back when, you could buy a 4-terminal LED which meant completely independent connections to the red and green LEDs but my memory is not what it used to be so I could be having a senior moment.  I can imagine a circuit to allow you to use a generic 3-terminal common-anode LED but it would not be a "simple" solution and would be probably like what you had initially imagined about some kind of relay solution.

I think the low-hanging fruit would be the momentary spring-loaded toggle switch to reduce panel space for the switch.  But I'm not so optimistic about finding a simple way to drill just a single hole for a bi-color LED.

This is copied and pasted over from the Z-Stuff page....  Looks like you have to use 2 LED's but still not a bad set up....  I am sure you can find 1K, 1/4W resistors in bulk for short money, or go to Mouser.com..

 Wish I had found this before I completed the mounting of over 25 -  DZ1002's..  I have no plans to tear up my control panels at this point..... 

You could elect to mount the LED's adjacent to on right on the center line of the track route on your panel...   Also, you might want to consider panel mount bezels with LED sockets, or 2 wire microi plugs, so you could pull and reverse the LED's if necessary. 

Thanks Chris, stumbled upon that earlier. That's probably what i will do seems to be simple and fits the K.I.S.S. theory. 

gunrunnerjohn posted:

Stan, he just needs a common cathode bi-color 3-pin LED, both of those LED outputs are positive in respect to ground.

I've got plenty of those LED's left over from the classification light installs  

gunrunnerjohn posted:

Stan, he just needs a common cathode bi-color 3-pin LED, both of those LED outputs are positive in respect to ground.

  LED3 and LED4 do NOT share a common cathode.  Depending on the position of the microswitch sensor, you either light up both Reds or both Greens with the current path as shown.  Different polarity of the AC signal is used to drive the two colors so the LEDs are driven by half-wave rectified pulses. 

And of course when a pushbutton is pressed it applies half-wave rectified pulses of proper polarity to drive the DC motor to toggle the microswitch.

So I don't see how a 3-terminal common-cathode LED could be used?

I see all kinds of 4-terminal red-green LEDs but only in surface-mount form which would be hassle to work with plus mate to a lens to project thru a control panel.

If using 2 LEDs and 2 panel holes is acceptable that's clearly simplest.

Sorry Stan, wrong thread, I meant this to be in the TT thread using the MiniCommander II, don't know how it got here!

I deleted my original reply to avoid any further confusion.

It seems to me there are two separate things going on here.  First, how to use a bi-color LED with the switch machine/controller instead of two separate LEDs. Second, how to use a single push-button instead of two.  I'll tackle the LED issue first, since that seems to be the focus of late.  I'm sure there are other ways to do this, but this is the first thing that popped into my head.  

In place of the LEDs in use in the current controller design you could use a pair of  opto-couplers.  Then use the switching action of the OCs to turn on and off the anodes of a 3 leg  bi-color LED.  This is quick and dirty, and may need refinement, but something like this:

You can likely find an Opto with two in one dip package, I just don't have one I could find in the program I use for schematics.  I also didn't have a bi-color LED, only a tri-color, so ignore the blue LED leg.  

As for the single button, the first question is, does it have to be momentary as the original controller is?  I'm guessing that it does, as the LEDs in the controller would not light if the button is held down, and in the schematic posted above by stan, there doesn't appear to be anything to keep the motor from running.  Not really sure what's in the guts here.  If you can leave the button pushed, than any push-on/push-off double throw button should do the trick.  If you need only a momentary contact on the other hand, there are a couple solutions that come to mind. The simplest one as far as easiest to put together for someone that doesn't want to scratch build something at the component level would be to use a timer-relay module from the auction site and perhaps a second relay module along side to direct the power in the right way.  This would also need a DC power source for the modules.  

One could get the same job done in various ways with discrete components, whether using relays, transistors a flip-flop, or even a micro-controller.  each has advantages and disadvantages in complexity and cost.  My opinion is, if you only have one or two switches that need such a controller, the pre made module approach is easiest, though it will set you back $15-20 per switch.  If you have many switches, the Micro-controller is likely the easiest, least expensive solution, costing about $10 plus $10 for every 8 switches.  

JGL

In another type of solution, I've actually had good luck stacking LED's.  I had an occasion where I wanted red/white, and so I stacked the white LED in front, formed the leads 90 degrees to fold around the red LED in back.  I put heatshrink around the pair to keep them in alignment, then they were wired separately into the driving circuit.  It actually works amazingly well.

For red/green in a similar way, just use the water clear colored LED's, you can get all colors in clear plastic.

This has the benefit of no additional circuitry, worth a shot...

Would you have a picture of this heat shrink arrangement ?  I am looking for a simple method for "DIY Dwarf", and using heat shrink could be a solution.

Good idea!  

Never thought of that so had to try it myself.  In a slight variation to your method, I mounted a 0805 (.08" x .05") surface-mount Green LED to the back/bottom of a 5mm clear-lens Red LED.  Picture is a thousand words:

Unless you really enjoy soldering microscopic parts, I do NOT recommend trying this at home! 

Looks good Stan, that is a variation on the idea.

@stan2004 posted:

  LED3 and LED4 do NOT share a common cathode.  Depending on the position of the microswitch sensor, you either light up both Reds or both Greens with the current path as shown.  Different polarity of the AC signal is used to drive the two colors so the LEDs are driven by half-wave rectified pulses.

And of course when a pushbutton is pressed it applies half-wave rectified pulses of proper polarity to drive the DC motor to toggle the microswitch.

So I don't see how a 3-terminal common-cathode LED could be used?

I see all kinds of 4-terminal red-green LEDs but only in surface-mount form which would be hassle to work with plus mate to a lens to project thru a control panel.

If using 2 LEDs and 2 panel holes is acceptable that's clearly simplest.

Good morning, all!  I've been messing about with DZ-1000 switch machines for the last couple of days and came across this thread. 

I'm curios to know more about how the schematic above works.  What I'm not understanding is how the motor is not spinning in the configuration the schematic above is in.  The LEDs along the red path should be lit (on one half of an AC cycle), but I don't understand why the motor would not spin since its in series with the LEDs?  In the illustration above, current would have to be flowing through the motor to light the red path LEDs.  Why does pressing the push button on the left side of the schematic make the motor turn?  Does taking the LEDs and resistors out of the path give the motor enough voltage to spin (the doesn't make sense as an explanation since the DZ-100s operate on 9VAC to 14VAC).

Does anyone have an explanation they can share?

Without any button pushed the resistors in series with LED3 and LED4 restrict current flow through the paths containing those LEDs to about 30 ma or so max.  While this is enough current to light the respective LED when the opposite button is pushed it's not enough, even though this current is flowing directly through the motor's windings, for the motor to spin.  In this situation the motor looks and acts like an additional, low value, resistor to the circuit and not a motor.

When a button is pushed to activate the motor, it short circuits the associated LED, 3 or 4, and its resistor applying full current to the associated motor, which now spins as a result (and now looks like and acts like a true motor and no longer simply a low value resistor).  This LED, being short circuited, does not light.

In both cases the LED on the side for which the button has not been pushed is in series with the spinning motor, and not short circuited by a pressed button, and so it lights.

This circuit has been very carefully designed to do many things with only a few wires in between the pushbutton assembly and the switch machine.  It's an excellent example of what I call "Elegant Simplicity".

Mike

@Mellow Hudson Mike posted:

Without any button pushed the resistors in series with LED3 and LED4 restrict current flow through the paths containing those LEDs to about 30 ma or so max.  While this is enough current to light the respective LED when the opposite button is pushed it's not enough, even though this current is flowing directly through the motor's windings, for the motor to spin.  In this situation the motor looks and acts like an additional, low value, resistor to the circuit and not a motor.

When a button is pushed to activate the motor, it short circuits the associated LED, 3 or 4, and its resistor applying full current to the associated motor, which now spins as a result (and now looks like and acts like a true motor and no longer simply a low value resistor).  This LED, being short circuited, does not light.

In both cases the LED on the side for which the button has not been pushed is in series with the spinning motor, and not short circuited by a pressed button, and so it lights.

This circuit has been very carefully designed to do many things with only a few wires in between the pushbutton assembly and the switch machine.  It's an excellent example of what I call "Elegant Simplicity".

Mike

Thanks, Mike!  I agree on the elagance of the simplicity.  The clever mechanism of the machine also speaks the the elegance of the switch machine design.