Yamaha Music Sirens

[HDN]

Wow, what a find! Thank you for sharing these. I have a few responses to the comments left in the documents:

Music Siren Brochure (the older model)

If the song finishes during the cam’s rotation, it will repeat the same interval to continue the song. (???)

I think this means that if the song ends and the cam isn't turned off, the song will repeat.

The system is like a drum-style music box, except the drum is triggering switches for chopper dampers. Neat!


Music Siren 1989-01 (the newer model)

Automatic drain (?? tf does that mean lmao)

I'm guessing there's an automatic drain on a storage/buffer tank for the compressed air actuation system. When air is compressed in a tank, water condenses inside the tank and eventually settles to the bottom. These air tanks have drain valves on the bottom. If the tank isn't drained, the water will rust the tank out and cause a leak. Compressed air anything with an air storage tank needs a water drain valve - small air compressors you can carry around, large industrial compressed air systems, air brake systems on locomotives and trucks, etc. Industrial compressed air systems have automatic drains like the one described in the brochure to reduce system maintenance and not drain more air than needed to drain the tanks (compressed air at that scale costs a lot of money in energy bills, so it's important to not have leaks!).

Driver specs (whatever that means)

In the context of the "driver" specifications, it looks to me like the actual siren controller. The little computer that has the programmed songs sends data to the "driver" box, which tells the siren which notes to play at a given time. Looking at the picture on page 7, I think the driver box is the one pictured next to the controller. I imagine it weighs around a hundred pounds on the account of housing switches, relays, and other circuitry.

I find it interesting that a 10 horsepower motor is driving all those choppers. Yet we have sirens with a 10 horsepower motor that drive one chopper. Either 10 horsepower is overkill for something like a STH-10 or the choppers on the siren are actually quite small and light (aluminum choppers smaller than one on a Model 5 maybe?).


The brochure for the older model mentions a warning siren mode. I wonder what that sounds like... Would all the chopper dampers be open, or only two or three of them for a less-complex multi-tone signal?

Maybe one of us needs to get our hands on one of these sirens to find out

[tyrone8813]

Driver specs (whatever that means)

In the context of the "driver" specifications, it looks to me like the actual siren controller. The little computer that has the programmed songs sends data to the "driver" box, which tells the siren which notes to play at a given time. Looking at the picture on page 7, I think the driver box is the one pictured next to the controller. I imagine it weighs around a hundred pounds on the account of housing switches, relays, and other circuitry.

Yes, you're right, the driver is the big box with the start/cancel buttons and lights.

And the device that has the function of telling the siren what notes to play is the soft-touch controller, since that is where the “IC ROM” mentioned at the bottom of the picture is, and it uses MIDI programming for each song.

The controller is basically like a computer, since it has arrows to access the different functions like the tempo of each song and if you want to play a song manually or disable the timer, etc.

The driver would be the one that contains the star-triangle starter and the pneumatic system controller (the mechanical part of the siren.

Then to complete the system would be the Timer, which for some reason is not seen in the catalog, but is basically a quartz mechanical clock that controls the time and has an electronic device in case the mechanical one fails or simply to change the time if it is delayed or just stop the timer for maintenance.

Also, the controller has a backup battery, and i don't know why, because the siren would not work if there is a power outage, so I think if the controller went out in a power outage, it would be deprogrammed and you would have to synchronize it with the timer again, obviously this is just what I think would happen.

[HDN]

Then to complete the system would be the Timer, which for some reason is not seen in the catalog, but is basically a quartz mechanical clock that controls the time and has an electronic device in case the mechanical one fails or simply to change the time if it is delayed or just stop the timer for maintenance.

Also, the controller has a backup battery, and i don't know why, because the siren would not work if there is a power outage, so I think if the controller went out in a power outage, it would be deprogrammed and you would have to synchronize it with the timer again, obviously this is just what I think would happen.

I assumed there was a digital timer integrated with the controller. In that respect, it amazes me how much the technology changed with the way the sirens work between the first and second generations of music sirens - from cam wheels to computer chips!

It would be a good idea to have that backup battery for the controller too. I'm guessing it's like how computers usually have some kind of CMOS battery. It seems like it takes some effort to program the thing, especially if there's custom stuff going on there.