Large Scale Central

Using a Three Wire Pulse Generator/Hall Sensor

Problem Solving
#1

Does anyone have experience using a three wire pulse generator/hall sensor on a sound decoder without a specific connector for it? I’ve installed a Massoth Pulsed Generator into an LGB Uintah steamer originally to connect to a Massoth XLS Sound decoder which has the three pin connector for the pulse generator. But now my customer instead wants me to install a Phoenix P8 sound decoder which as a connection for a two lead chuff reed switch. The Massoth decoder documentation indicates the three lead pulsed generator connections as: Ground; Clock; 6.5 volts. So, I’m not aware whether the Phoenix decoder can support a pulse generator without a clock feature?

Thanks

Tom

Note: I’ve posted a photo of the Massoth Pulse Generator unit that I installed into the LGB Uintah, for those not familiar with pulse generators that produce the chuff input into a decoder’s clock connector.

#2

I would contact Phoenix. It would seam to me that they should know.

#3

It really depends on the hall sensor output (which normally goes to ground), and the phoenix requirements for the chuff trigger.

It might work as is (clock is really the hall effect output) and the phoenix chuff trigger needs to be pulled to ground as I remember.

Might work as is, or you may have to “amplify” the current with a single transistor.

Double check the assumptions in #2 sentence and if right, hook them up. Don’t overvoltage the hall sensor most work fine on 5v

Greg

#4

All the hall sensors I have ever worked with USE a 5v reference signal with a ground. The 3rd wire will be pulse generating or square wave pattern on a scope. Nothing more than an on/off signal passing a magnet. However I have never worked with them in a model train application only 30+ years in the automotive repair industry which uses them quite frequently.

With that said I will let the experts help you out Tom as I don’t want to be an attack dog here or post fowl language.

Good luck and please post your results

Rooz

#5

I have a set of pick-up trucks that had a Hall pick-up mounted. The axle has a rubber “tube” in the center that rotates with the wheels. This counter-rotates a “tube” magnet mounted on an axle just above that spins in front of the sensor. When I spin the wheels and place a compass next to this tube magnet it goes N/S/N/S/etc.

It would seem to me that any Hall set-up would also require a magnet that spins in proximity to teh sensor, and perhaps, you could just replace the Hall sensor with a reed switch and wire that accordingly.

#6

David Maynard said:

I would contact Phoenix. It would seam to me that they should know.

David - Yes, I’ve already sent them a message asking for their advice. But there may be some folks on this forum that have already dealt with this issue, so thought i’d “pulse” them here too.

Tom

#7

Todd Brody said:

I have a set of pick-up trucks that had a Hall pick-up mounted. The axle has a rubber “tube” in the center that rotates with the wheels. This counter-rotates a “tube” magnet mounted on an axle just above that spins in front of the sensor. When I spin the wheels and place a compass next to this tube magnet it goes N/S/N/S/etc.

It would seem to me that any Hall set-up would also require a magnet that spins in proximity to teh sensor, and perhaps, you could just replace the Hall sensor with a reed switch and wire that accordingly.

Todd - I just posted a photo of the Massoth Pulse Generator Unit that I installed in the LGB Uintah…the round magnet is mounted onto the axle and rotates over the three wire sensor.

Tom

#8

Greg Elmassian said:

It really depends on the hall sensor output (which normally goes to ground), and the phoenix requirements for the chuff trigger.

It might work as is (clock is really the hall effect output) and the phoenix chuff trigger needs to be pulled to ground as I remember.

Might work as is, or you may have to “amplify” the current with a single transistor.

Double check the assumptions in #2 sentence and if right, hook them up. Don’t overvoltage the hall sensor most work fine on 5v

Greg

Greg - I sent an email last Monday to the Phoenix Sound folks and awaiting their advice…if a pulse generator unit has been successfully connected to one of their decoders I’m sure they’ll know about it, or can also say whether it will work or not. It appears your thoughts are to attach the pulse generator wires to the regular two chuff inputs to the Phoenix decoder (ground and chuff) and the third wire to some 5volt (Massoth decoders use 6.5 volts) connection on the decoder…that’s what I also thinking but not sure which connection to obtain it. So I think I’ll wait for the Phoenix folks’ response before I try anything.

Tom

#9

yep, you will need not only a regulated voltage, but to be sure to use the Phoenix ground and I would regulate the 5 volts from the supply that feeds the Phoenix.

Otherwise the ground reference won’t be right for the Phoenix.

Greg

#10

Greg Elmassian said:

yep, you will need not only a regulated voltage, but to be sure to use the Phoenix ground and I would regulate the 5 volts from the supply that feeds the Phoenix.

Otherwise the ground reference won’t be right for the Phoenix.

Greg

++++++++++++++++

Greg - Here’s the response I received from Jim/Phoenix Sound…does it sync with your comments?

If the hall sensor is to be powered by the Massoth power decoder, you may only need to connect the Hall output (chuff) to the Phoenix Chuff trigger input. If the Phoenix sound board is to power the hall sensor then the ground connects to Phoenix ground/trigger ground, the hall output to the phoenix chuff input and the hall +5V to the Phoenix +5V (Volume switch +5V connection is a good place to grab that).

#11

" Rooster " said:

All the hall sensors I have ever worked with USE a 5v reference signal with a ground. The 3rd wire will be pulse generating or square wave pattern on a scope. Nothing more than an on/off signal passing a magnet. However I have never worked with them in a model train application only 30+ years in the automotive repair industry which uses them quite frequently.

With that said I will let the experts help you out Tom as I don’t want to be an attack dog here or post fowl language.

Good luck and please post your results

Rooz

#12

Yes Tom, at the very least, you need to have the same ground reference, thus the suggestion to connect the grounds.

The iffy point is if the 5v from the decoder will “reference” to the 5v in the Phoenix.

In the strictest sense, if the grounds are connected together, and “going to ground” is the trigger (as I believe), then most likely either 5v should work, but often “should” translates to “maybe”. :wink:

Let us know how it works out, but I suspect it will work either way. If you get into trouble, I would use a 5v supply to the hall effect referenced to the Phoenix.

Best, Greg

#13

Greg Elmassian said:

Yes Tom, at the very least, you need to have the same ground reference, thus the suggestion to connect the grounds.

Best, Greg

What ???

Never mind …

#14

Rooster, re-read the response from Phoenix re: connecting grounds and what Tom asked me if you are confused

#15

Greg Elmassian said:

Rooster, re-read the response from Phoenix re: connecting grounds and what Tom asked me if you are confused

I did Greg …however it matters not to me as you are ALWAYS correct and I could care less. I’m only following along listening to the expert advice shared on Large Scale Central no where else.

Hopefully Tom will post his results

#16

Sigh rooster.

  1. if it did not matter to you, then why make comments like you did: “what??? Never mind”

  2. if anyone was to believe your “i’m only following along and don’t care anyway” after all your posts, they would have to have a room temperature iq

  3. If there was even a CHANCE you were being serious about understanding, instead of just being a rooster, then I would be happy to explain it to you.

Sorry you feel your duty is to act this way, to the point you cannot even stifle yourself when you “don’t care”

Greg

#17

Greg and Rooster - I have some other sound system projects taking priority right now, so it will be awhile before I’ll be able to test a hall sensor with the Phoenix sound board and Massoth decoder. But once I do it, I’ll certainly post the results, successful or unsuccessful, for everyone.

Thanks for both your inputs.

Tom

#18

I don’t know if this is helpful since the last post was two months ago.

But I’ve installed a Hall effect to a PB11.v6 version of the sound boards.
Albeit into a Ride-on 7.25inch scale locomotive, however the principal should be roughly the same.

This method also worked for a PB17 version, that I bought as a spare.
(I do not know if this will work for the current P8 and P14 sound boards.)

Ok, for anyone else who needs some help with Phoenix sounds to and 3 wire Hall effect switches.
Here is what you need to do.

1. On the Hall switch find outputs of each 3 wires is assigned to.
They should be, a Positive, a Negative, and the Signal.

Just like the instructions for a standard reed switch version.

2. the Signal wire needs to go into the chuff sensor terminal.

and the Negative wire goes into the suggested negative terminal.

3. Now, the positive wire, need to connect to the +5V.
On the PH17 this is also the volume up terminal, so you need to share it.
(I think the P8 has a separate terminal for +5V)

Give a test and see if it all works.
If it does, YAY! :smiley:
If not, then my instructions are a dud, sorry! :frowning:

Optional.
On my Ride on, the trigger magnet spins much to fast for the programming to keep track of the pulses.

If you have access to the PC programming.

  • Under Feature Set.
  • Terminal Polarity.

Find the one assigned for Chuff Sensor.

And change the Active Low, to Active High
It’s usually just a tick option.

#19

Matt - Thanks for your input. It appears to match closely the guidance I received from Jim at Phoenix Sound. I haven’t tested the Massoth Hall Sensor wiring yet on a Phoenix PB17 but what I was concerned about was the 6.5 volts specs for the Hall Sensor. Didn’t know whether the Phoenix’ 5 volts would be sufficient but you’re finding that it is.

#20

Thomas White said:

Greg and Rooster - I have some other sound system projects taking priority right now, so it will be awhile before I’ll be able to test a hall sensor with the Phoenix sound board and Massoth decoder. But once I do it, I’ll certainly post the results, successful or unsuccessful, for everyone.

Thanks for both your inputs.

Tom

Tom ,

Good luck…I personally don’t run sound on my ghetto roundy round RR but I do understand Hall triggers with my profession.

It’s all good !

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