Anybody know of a simple method for adding a bell function to a postwar ZW? I read that bell is the same principle as the whistle/horn, just reversed DC bias on the AC output.
I think the trick might be the way Lionel added a couple of volts AC boost when the horn button is full on. How would you do that with the Bell function? Or is it really needed?
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The Lionel 5906 is probably the simplest way to add bell function.
Or, if you are using a Type Z/V etc., w/o any whistle or bell control, you use two:
And here is how you would use it (Since you are using a PW with a whistle activator, you can omit the one labeled "HORN OR WHISTLE ACTUATOR"). And for the Bell, there is no need for the 5VAC boost.
(ROB you must have edited yoiur post and added the picture while I was posting mine - not trying to step on toes!)
GEOPEG,
Rob is correct however I would simply add DCS to your layout and run all the different control functions from the DCS Hand Held Remote Control, expanding the layout control big time.
PCRR/Dave
Rob and Bmoran4, thank you! That makes perfect sense - I knew there had to be an easy way! I'll dig into my box of diodes to see what I have, maybe string my own together.
I found this while you guys were busy replying, and it is probably what is inside the Lionel 5906 already?
That made me realize that all I really need to add is this:
which should provide about a 0.7 volt bias in either direction (and drop in track voltage) depending on which normally closed button is pushed - If 0.7 volts isn't enough, I could string together a few more on each side until I found the right number to trip the horn and bell circuits. Seem right to you?
And PCRR Dave - I would love to go DCS, but am completely unknowing on the topic - trying to find some reference material something along the lines of DCS For Dummies, or similar. Also, a small loan would be helpful - from what I have seen, that stuff can get expensive! I have deep pockets, but only because they both have holes in them 
Can you recommend the cheapest way to get in the door using my postwar ZW? Or not?
GeoPeg posted:I found this while you guys were busy replying, and it is probably what is inside the Lionel 5906 already?
Check THIS LINK for details on the 5906...
GeoPeg posted:That made me realize that all I really need to add is this:
Since both of those switches are in parallel, they each do the same thing. AND, since the diodes are in anti-parallel, there will be no DC current at all, only a .7 volt drop when, & if, both switches are activated(opened).
ADCX Rob posted:GeoPeg posted:I found this while you guys were busy replying, and it is probably what is inside the Lionel 5906 already?
Check THIS LINK for details on the 5906...
GeoPeg posted:That made me realize that all I really need to add is this:
Since both of those switches are in parallel, they each do the same thing. AND, since the diodes are in anti-parallel, there will be no DC current at all, only a .7 volt drop when, & if, both switches are activated(opened).
Ooops! That was a forehead slapping moment 
I'm blaming the late hour .... folks have said I do my best work late at night, can you imagine what my mornings are like?
Back to the drawing board. How about this? VERY similar to the circuit in the link above, but minimizing the
number of diodes used. Do you think this will give enough dc offset to trip the horn/bell circuits?
Maybe... can't hurt to try.
I can't recall if it is 5 or 6 diodes used in the store bought activator button, but it is about that number. I think it was 5 and a 6th strung in the opposite direction parallel to the string of 5. I also think they used 6 amp diodes, so you'll want to make sure that whatever diodes you choose to use can handle the current draw of your set-up.
Another option, though a little more involved could be to rewire the rectifier in the ZW with a switch that allows it's polarity to be reversed, though this is more of a passing idea and I'm unsure exactly what would be involved.
JGL
JohnGaltLine posted:I can't recall if it is 5 or 6 diodes used in the store bought activator button, but it is about that number. I think it was 5 and a 6th strung in the opposite direction parallel to the string of 5....
ADCX Rob posted:
I made a box like this years ago, it took a total of ten diodes to get it to work reliably. Ignore the extra terminals on the pushbuttons, it was a junkbox build, and those were the switches I had handy. The switches are wired NC, they open when pressed. Each switch shorts four of the five diodes in the string for normal running so only one diode pair is in the power path. Either switch gives a DC offset, one negative, one positive.
Given the immense number of comments regarding the whistle/bell hookup to a ZW transformer, including the discussion of the Lionel 6-5906 whistle controller, I was surprised when I saw a Lionel 8251-50 on you tube, and the guy demo's its performance against the standard Lionel 6-5906 - If his test was valid, I'm curious why the 8251-50 outperformed the 6-5906 by such a large margin? Anyone have experience with it?
Here's the video for the 8251-50
It would have been useful had he showed us what the circuitry was like in the good one.
gunrunnerjohn posted:It would have been useful had he showed us what the circuitry was like in the good one.
True, especially since he took the time and effort to bust it open, then rubber band it shut 
I watched the whole stinkin' video hoping he's illuminate what was in the case, I was bummed that he didn't.
I'm actually more interested in the inner workings than opinions of it's quality. I think either of those buttons have equally low quality. 
AFAIK, to get whistle /horn function you introduce a positive DC voltage that floats the std sine wave signal from the ZW. For bell function the DC voltage polarity is just reversed.
The problem with the 8251-50 is that it can't be used with common ground layouts because it uses a diode in each leg - common & center rail. On common ground layouts, the common leg would be shorted to ground leaving that one diode out of the circuit. If those two little diodes are rated at even one amp I'd be surprised. I have one disassembled, but I believe it's in my office somewhere at work, I will look for it after I get my corp. taxes in to the accountant.
Meanwhile, here are a few views of the very similar K-Line K952B controller. They made a couple of improvements to the 8251-50 by employing a 4 amp full wave bridge rectifier switched into the track circuit by a make-before-break DPDT pushbutton switch and a 470 µF filter cap across the - & + leads of the bridge. There is no attenuation or boost circuitry. Additionally K-Line provided a DPDT slide switch to select whistle-horn or bell functions. This would obviously cause a problem with common ground layouts... being able to switch the electrical polarity of one power district in a whole layout... but is not a concern with powering just one loop of track as found in the K-Line sets. I think this box came from one of the K-Line Girl's sets.
I think I get it now. They only switched in diodes when they wanted a DC offset, that's the reason for the more complex switching.
gunrunnerjohn posted:I made a box like this years ago, it took a total of ten diodes to get it to work reliably. Ignore the extra terminals on the pushbuttons, it was a junkbox build, and those were the switches I had handy. The switches are wired NC, they open when pressed. Each switch shorts four of the five diodes in the string for normal running so only one diode pair is in the power path. Either switch gives a DC offset, one negative, one positive.
John, I'm just getting around to building this, and emulated your design (why reinvent a wheel that works, right?)
I did some testing before stuffing it all in a box - I jumpered one diode on each leg out of the circuit to see if I could get the whistle to blow and the bell to ring reliably with less of a voltage drop. 3+1 diodes is not reliable, however 4+1 diodes is right on the ragged edge, triggering bells and whistles with an AC input voltage to the controller of 8 volts, so I will go with that. What has been your experience with the 4+1 combo? Do all whistles and bells trigger properly, even at lower voltages?
Well, some designs used 5+1, so that might be a good idea to just add one. I just ended up with this and it workd. It was only a bench tool for testing, I haven't dug it out in some time.
Yes, I saw the 5+1 designs. Notwithstanding that, I wired everything up as 4+1 and gave it a run - Fail! No bell, no whistle.
After a short amount of troubleshooting, I disconnected the 2nd feed to the tracks on the opposite side of the layout and boom! Everything works as advertised. Holding the disconnected wires to the 2nd feed, and touching them momentaril while I am blowing the horn, the horn ceases - pull one of them away from the A terminal while holding the button, and the horn works again.
The second feed is just that, a parallel hookup of the track wires, so I'm not sure why I'm losing the DC offset. The track has some bad spots in it, even with the 2nd feed, the engine noticeably slows (not blowing the horn) in certain areas and the engine sound also decreases RPM.
Thoughts?
Hard to say, poor track connections can do all sorts of odd stuff.
Does someone make a triac-like circuit that maintains the AC voltage while differentially raising/lower the positive/negative voltage? It seems to me the amount of assembly/soldering effort of multiple diodes is substantial relative to the cost of the components whether a string of diodes or triacs. That is, if going through the effort why not let the engine maintain speed (rather than slowing down) when you hit the bell or whistle button?
gunrunnerjohn posted:Hard to say, poor track connections can do all sorts of odd stuff.
And yet another late night, forehead slapping moment. 1st feeder hooked to output of whistle controller, 2nd feeder hooked directly to ZW. Duh! Sometimes it's like I don't know which end of a "D" cell is positive ....... all is well in 3 rail-land.
stan2004 posted:Does someone make a triac-like circuit that maintains the AC voltage while differentially raising/lower the positive/negative voltage? It seems to me the amount of assembly/soldering effort of multiple diodes is substantial relative to the cost of the components whether a string of diodes or triacs. That is, if going through the effort why not let the engine maintain speed (rather than slowing down) when you hit the bell or whistle button?
If somebody has that circuit, I'll be first in line 
Stan, sounds like an opportunity to excel here, let's see your circuit with the triac! 
Yes you can make them but just buy the 5906 and it's done.
stan2004 posted:Does someone make a triac-like circuit that maintains the AC voltage while differentially raising/lower the positive/negative voltage? It seems to me the amount of assembly/soldering effort of multiple diodes is substantial relative to the cost of the components whether a string of diodes or triacs. That is, if going through the effort why not let the engine maintain speed (rather than slowing down) when you hit the bell or whistle button?
I was trying to sketch something up the other night that worked along those lines. The problem is that triac designs depend on accurate timing with respect to the AC voltage. Cheap light dimmers and motor speed controls do it by assuming the input voltage/frequency/waveform is constant and by using instantaneous voltage as a proxy for time. But when the input voltage (and perhaps waveform) is variable, that won't work. So far I haven't come up with a way to get an accurate time delay without a DC supply. I was thinking of charging a cap through a constant-current source but it would need to be bi-polar to work with a triac. So far the best looks like the old-fashioned SCR in the middle of a bridge, then I could use a CC source of a single polarity, but there are a lot of diode drops involved. Then, of course, somebody would want to use it on a shark-fin waveform, which throws it all out the window.
I don't have a simple solution in my back pocket. Maybe an outboard PW whistle unit, with an integral transformer to supply the boost/DC voltage would be a viable option!
The self-powered aspect seems to be somewhat of a sticking point.
I don't think the solution would be "simple" relative to a bunch of 25 cent diodes. I agree the thorny issue is the "self-powered" aspect to effect what is apparently referred to as the "AC boost" if the whistle/bell was integral to the transformer housing to pick-off a different (higher voltage) AC tap.
The point is the diode string method burns Watts and Watts of power when active - albeit for a short time. With modern switching components I'm just curious whether someone took it upon themselves to steal what I'd think would be, say, 1 Watt of power to perform the logic and timing to insert DC offset.
stan2004 posted:With modern switching components I'm just curious whether someone took it upon themselves to steal what I'd think would be, say, 1 Watt of power to perform the logic and timing to insert DC offset...
You mean like this(bell & whistle starts at :31)?
Essentially yes. But the CW offset insertion circuit has the advantage of a known/fixed voltage input (18V AC or whatever). This would be like MTH Z-controllers which start from a known/fixed voltage input from the black brick.
In the ZW case, the starting voltage can be, say, 7 VAC to 20 VAC or whatever the range for conventional control.
I'm curioius about the speed-change issue. As I see it, simple "subtractive" techniques which whack off some portion of the negative or positive AC voltage resulting in a net DC offset will have a speed drop because there is simply less voltage there. Hence that's why (apparently) the transformers that offer integral whistle/bell control boost the AC voltage.
I'm making the observation that with modern components (which might even include a 25 cent micro-controller chip loaded with software to perform logic or timing) including high-current solid-state devices, it seems it would be possible to make a minimally invasive widget that delivers essentially all of the original voltage (less a 1 Watt "tax" to power the electronics). Apparently this is not the case.
Let's also remember the recent thread about the ERR Sound Converter, it whacked off a certain portion of the sine-wave, but it doesn't trigger all whistles.
PLCProf posted:stan2004 posted:Does someone make a triac-like circuit that maintains the AC voltage while differentially raising/lower the positive/negative voltage? It seems to me the amount of assembly/soldering effort of multiple diodes is substantial relative to the cost of the components whether a string of diodes or triacs. That is, if going through the effort why not let the engine maintain speed (rather than slowing down) when you hit the bell or whistle button?
I was trying to sketch something up the other night that worked along those lines. The problem is that triac designs depend on accurate timing with respect to the AC voltage. Cheap light dimmers and motor speed controls do it by assuming the input voltage/frequency/waveform is constant and by using instantaneous voltage as a proxy for time. But when the input voltage (and perhaps waveform) is variable, that won't work. So far I haven't come up with a way to get an accurate time delay without a DC supply. I was thinking of charging a cap through a constant-current source but it would need to be bi-polar to work with a triac. So far the best looks like the old-fashioned SCR in the middle of a bridge, then I could use a CC source of a single polarity, but there are a lot of diode drops involved. Then, of course, somebody would want to use it on a shark-fin waveform, which throws it all out the window.
I don't have a simple solution in my back pocket. Maybe an outboard PW whistle unit, with an integral transformer to supply the boost/DC voltage would be a viable option!
Hands down, I think the suggestion to wire a simple C or D cell battery into one of the AC lines (using a pushbutton) is the simplest and most cost effective solution - and it works like a charm, although there's a bit of a switching issue to work out.
But I'm a bit fuzzy on the effects of a double header with a heavy load pulling, say, 4 amps of current through the battery. I know all batteries have an internal resistance, and I assume if you are pushing/pulling 4 amps through that D cell, there might be (heat) consequences. Most of the time the duration is quite short, so noticeable effects aren't obvious.
So can you do the same with a hefty wall wart? I have a couple of old laptop charger/supplies capable of delivering 4.5 amps - not that the bell circuit needs that much oomph, but rather it would probably have a fairly low internal resistance.
Why couldn't you add an adjustable 3 terminal regulator to regulate the output of a laptop supply down to a couple of volts and switch that in and out of the AC output from a ZW to drive the bell circuit? Fireworks?
GeoPeg posted:But I'm a bit fuzzy on the effects of a double header with a heavy load pulling, say, 4 amps of current through the battery. I know all batteries have an internal resistance, and I assume if you are pushing/pulling 4 amps through that D cell, there might be (heat) consequences. Most of the time the duration is quite short, so noticeable effects aren't obvious.
So can you do the same with a hefty wall wart? I have a couple of old laptop charger/supplies capable of delivering 4.5 amps - not that the bell circuit needs that much oomph, but rather it would probably have a fairly low internal resistance.
Why couldn't you add an adjustable 3 terminal regulator to regulate the output of a laptop supply down to a couple of volts and switch that in and out of the AC output from a ZW to drive the bell circuit? Fireworks?
The issue with using any DC power supply, battery or wall wart or what have you, is that, when placed in series with the AC track voltage, current will be forced backwards through the DC supply during half cycles when the button is depressed. Depending on the design of the power supply it might be damaged or it might just not work.
Lionel indeed made a whistle control that put batteries in series with the track, I think it was the 147. Worked fine, but the switch in that unit was flimsier than flimsy.
Someone will warn of the danger of catastrophic explosion if you put current backward through an alkaline D cell. I am sure that can happen if you continue it long enough, but I seriously doubt any ill effects in the normal short, intermittent use that a bell button gets.
Nevertheless, I did some research today and found that Eveready still makes the old Carbon-Zinc cells for which the Lionel 147 was designed. They are called "Super Heavy Duty," and they were on the shelf in my grocery store. The data sheet has no warning about explosion; it does say that trying to recharge them (which is what a reverse current does) may result in leakage. When I was a kid, you could buy ersatz battery chargers for carbon-zinc cells, they sorta worked, but the batteries grew weaker with each recharge.
I personally would have no reservation about trying/using the carbon-zinc cells in this application if that is your plan; as you point out it works, is inexpensive and is easily understood.
GeoPeg posted:Hands down, I think the suggestion to wire a simple C or D cell battery into one of the AC lines (using a pushbutton) is the simplest and most cost effective solution - and it works like a charm, although there's a bit of a switching issue to work out.
gunrunnerjohn posted:The battery method DOES work. And it's no big deal to put a brief heavy current through ni-cad batteries that were made for cordless power tools.
The diode array has to handle the full train current all the time; with about 4 volts drop that generates some heat and you need 10 heavy-duty diodes to handle typical postwar motors, up to 5+ amps with dual motors.
Photo shows my ni-cad battery whistle and bell controller, built into a plastic housing with a single-handle dual-SPDT micro-switch. I've wired two cells in parallel for each polarity. The parts were all salvage items.
GeoPeg posted:So can you do the same with a hefty wall wart? I have a couple of old laptop charger/supplies capable of delivering 4.5 amps - not that the bell circuit needs that much oomph, but rather it would probably have a fairly low internal resistance.
K-Line did this!
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