When a person such as myself who has a certain interest in Japanese culture (both junk-culture and otherwise) also happens to have a clock system and PA system, this is rather inevitable: an interest in the “Japanese school chime” equipment, that is. Unlike the rest of this site, most of this page concerns something I would like to own, rather than things I already own.

学校のチャイム (introduction)

Rather than bells, typical Japanese schools use chime melodies played over the building PA system to signal class changes. This is commonly known as 学校のチャイム (“gakkou no chaimu”; en: “school chime”). The standard chime consists of the part of the Westminster quarters that normally indicates the hour, without hour strike or the other “quarters”. This is the chime with which anyone who watches anime or reads manga (and probably anyone who landed directly on this page from a search engine) will be familiar.
For most of recent history, the gakkou-no-chime was produced by an electromechanical chime instrument connected to the PA system and switched by a program clock. There are many YouTube videos on this topic (created by people other than me). For example, “Natural sound: gakkou-no-chime (Westminster)” shows one of these instruments in operation (there are also many other similar examples in the search linked here, including most of the playlist linked here). Note the magnetic pickups (similar to an electric guitar) behind the chime rods. Another video, “Japanese School Chime”, shows a Matsushita National PA system head being automatically switched and playing what is likely the output of one of these instruments.
Of course, nowadays, those super-cool chime instruments are being replaced by fancy electronic devices—often referred to as 電子チャイム (“denshi chaimu”; en: “electronic chime”). There are also several video examples of those devices.

メロディ試聴 (melody audition)

An example of a device containing an electronic chime unit is the M version of the Seiko Time Systems QT-5800 series electronic master clocks. According to the specifications, they use a “Dual Wave Synthesis sound generator” chip to produce ten selectable chime melodies.
Sample copies of the melodies played by these master clocks are freely available in mp3 format on the company website. In addition to the ten titles named under 【 メロディ試聴 】 (“melody shichou”; en: “melody audition”) on the product page, four additional melodies are also available. I recommend downloading all fourteen of them, if you’re interested in this sort of thing. (Simply modify the two links below.)
Of particular interest are the two named ウエストミンスターの鐘 (“Westminster no kane”; en: “Westminster bell”)—files 01 and 11. The first is the standard fast electronic-sounding chime (23sec, 80kbps) that is likely common these days. The second is a slower, more mechanical-sounding chime (27sec, 64kbps). Despite the very low bitrates, I am fairly certain these are the best source recordings of such chimes that have been made freely available on the internet. If I’m wrong, I’d love to know about it (please).

学校のチャイム、うちの (my setup)

So, despite the fact that I do not normally like the idea of using a PA system as a timed signal device, I did it anyway. I modified a portable CD player such that an external contact can hold the play button electrically and loaded a disc containing only the Seiko #11 chime. I connected that such that the CD player is triggered, the PA system power is held-on, and the program source is switched by a relay, for the duration of the hourly correction cycle of the SET GRC clock system (the final thirty seconds of each hour). It is also silenced by Control #7 in the LTR8-128. Unfortunately, since I didn’t want to externally source the duration, it can only be operated on the hour.
So, now my residence—Oubei Gakuen—has the gakkou-no-chime broadcast over the PA system, every hour from 6:00am to 11:00pm. (This is not a correct model of a typical Japanese school, I think, but it’s cool nonetheless.) As soon as I find a suitable mp3 player to modify, the mechanical CD player (that tends to experience a mechanical failure at least once a month) will be replaced, at the very least; photographs may be forthcoming after I fix that. In any event, I have gotten rather used to this ambient sound now.
Otherwise, I would absolutely love to have one of those electromechanical chime instruments. (See Taihei TC-3, especially.) Definitely. It is, actually, the “number-one” thing that I want to acquire, in terms of my “collection”.
One of the things I would certainly do if I had one of these (other than connect it between my clock and PA systems, obviously) is to make a direct source recording of the audio signal output, and freely distribute said recording in a high-quality digital format. I’m certain it would be very popular. Why hasn’t anybody done this yet? (Please tell me if someone has done this!)