What is it for?

I came across this old device that was being thrown out and I don't know what it would have been used for. It is obviously built specifically for something and not just thrown together. The nameplates have "The Holtzer-Cabot Electric Co" on it.The base that the Motor and generator are mounted to is one piece of cast iron. The motor is a 110 VAC to 1150 RPM motor coupled to what I believe to be an 80V Generator. Why you wouldn't use a transformer is what has me baffled. It appears that their is only two terminals on the generator so I don't think its a different phasing. Maybe a different frequency?


Curious what everyone thinks!

motor generator for making DC. not an unusual arrangement

It could be a DC motor generator, possibly to power the transmitter section of radio gear.

Looks a lot like their telephone "mags" which were not DC but ALTERNATORS making AC to ring the ringer

HC was one of the many independent early telephone equipment makers

Original 1912 Holtzer Cabot Electric Catalog Telephones Vintage Auto Parts Etc | eBay

Does look a lot like a telephone generator,but more magnets. Those telephone generators would put out a good jolt.

Handy for making these things ring to beat the band. Can't tell if tag says 80 volts AC, but it might.

The positive and negative AC pulses worked with the pair of coils to oscillate the clapper between the pair of bells.

The 1150 RPM would do this at not quite 40 Hz (we used to say cycles) and damn sure get your attention

RARE Holtzer Cabot Electric Fire Alarm Bell Telephone Type LRE Boston Chicago | eBay

From what I understand telephones work of 48vdc batteries that were contained in open glass cells at the nearest switching station. Ring voltage is 90vac at 20hz. The name plate does not state 80volts ac or dc. But I doubt their is any rectification, but then again it could be like an old car generator that creates DC.

I had the identical unit once and have seen another at a swap meet. I was told they came from telephone switch locations for providing DC current. Mine was mounted to a heavy chunk of slate. I had no luck selling it intact, so I split it up and did well on eBay. The generator will interest the old time gas engine collectors looking for something fun to run with their Maytag and similar size motors, neat old electric motors always sell good on eBay. I think I got about $300 for the generator / dynamo and about $100 for the motor. Attached is pic of it running and powering a lightbulb, not sure why, but the pic loaded upside down?

johnoder said:

Looks a lot like their telephone "mags" which were not DC but ALTERNATORS making AC to ring the ringer

HC was one of the many independent early telephone equipment makers

Original 1912 Holtzer Cabot Electric Catalog Telephones Vintage Auto Parts Etc | eBay

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I was under the impression that telephones ran on DC, with alternating DC to ring the bells. Back in the days of party lines, it was common to have many parties on a line but only a quarter of the phones would ring at any time. Each phone had a ringer with two DC coils sharing a common ground, and a spring that either centered the ringer or biased it to one side or the other. All ringer signals would pass through the line, but if the bell was biased and wired for party service, some would pass to a disconnected coil, and some would be inaudible because the bell clapper was already forced by the spring to the position it would travel to when energized. Back when I lived in Northern NY in the 1970's the standard was eight parties to the line, with each phone getting a single or double ring. Look inside an old fashioned bell phone and you'll see the multiple bell connections and the biasing spring.

I believe that is a home made set. The reason I say that is the Holtzer-Cabot 1150 rpm motors were used in automatic musical instruments. The electric motors were connected to the vacuum pumps that required a slower speed than the normal 1750 rpm motors provided. You would find identical 1150 rpm motors in coin operated pianos and orchestrions. These motors are quite sought after by restorers of these instruments.
I have an identical motor with additional markings for the Wurlitzer company.
Keith

I was under the impression that telephones ran on DC, with alternating DC to ring the bells

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Just cranked the 1900 Swedish American oak wall phone. Registers on AC mode but not DC on the Volt / Ohm meter

The reason I say that is the Holtzer-Cabot 1150 rpm motors

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Both motor and alternator / generator are HC products.

How can it be a home made set?

Alternating DC is AC, From what I read there was two methods of isolating rings on a party line. Other than changing the ring pattern

1) Instead of putting your ring voltage across tip and ring like normal, refferrence it to earth ground and either tip or ring depending if you are calling tip party or ring party. But that is only two combinations.

2) vary the frequency at which you ring and only have the ringer respond to the frequency in which it is susposto. I wonder if they would have a bank of these running all at different speeds/ frequencies and switch in the one they needed to ring the intended party.

I think I'm going to have to fixed the frayed wires that go into the motor housing and power this thing up and see what it puts out.

Johnoder is correct, it is a 20 Hz AC ringer MG set.
If you take the nameplate cover off the alternator, you will find 2 slip rings.
If it produced DC there would be commutator bars, and the brushes would be opposite each other.

Newer systems use Subcycle units with magamps and tuned reactors to generate the 20 Hz from standard 60 Hz.

This is one of the newer ones: Subcycle BX60 5805002547759 Static Ringing Generator | eBay

Bill

The generator part looks so old school. They went back to horsehoe type magnets instead of using some type of electric exiter, has to be seen to be believed. That generator is like...1860s 1870s style - before Werner Siemens, Nikola Tesla and others created the variety of modern electric machines. Which have not changed very much since.

Dont scrap it - its lovely.

They went back to horsehoe type magnets instead of using some type of electric exiter, has to be seen to be believed. That generator is like...1860s 1870s style

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Be that as it may - MILLIONS were in use right up to WW2.

johnoder said:

The 1150 RPM would do this at not quite 40 Hz (we used to say cycles) and damn sure get your attention

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I can attest to that quite well. I was layed up in an interconnect rack where we were cutting our microwave MUX circuits into the switching rack, when some bonehead at the switch decided to ignore the tagout notes on the ringing generators. He flipped the switches on all four of the units and proceded to do try to do a load test. With me shorting out about 1800 lines with my body, it didn't go so well. Before I could get out of the rack, he had tried the test about six times. Fortuantely for him, the Northern Telecom guys hustled him out of there and locked the switchroom before I could get across the building and throttle him. I still despise wirewrap racks to this day.

"From what I read there was two methods of isolating rings on a party line. Other than changing the ring pattern"

The harmonic ringer wasn't used often. Typical party lines were done so you could get four sets on one line:

1) selective ringing from one side or the other of the line, to ground. This was mentioned above.

2) Polarized ringing, where DC was imposed on the AC ring voltage, either positive or negative polarity. The
ringer in the subscriber's set had a spring that could be put to press the clapper to one bell or the other. If
the polarizing dc pushed the clapper towards the bell it was already resting on, no sound would occur. The
set with the spring set in the other direction, would of course ring at that point.

This provided four easy possible multiplexed ringers on one twisted pair.

My neighbor to the south, had at one time been on a party line. He came to me one day and said, his phone
stopped working (ringing). I guess the central office finally got rid of the card he was on, that knew about
his particular ringer setup.

His phone was indeed set to ring from line to ground, and with the spring set on the ringer. I changed it out
and all was well. This incidently was a modern model 500 desk set, so that dated the party line.

The long/short pattern rings were used on bridging magneto service where one line went out into a sparsely
populated area, serving 10 or 20 subscribers. Often the set had the ring pattern listed on it. This kind of
service was still in use for a suprising amount of time. I recall such a party line that ran up the canyon
in arizona, as late as the early 60s.

At one point the telco installed a satalite link at the bottom of the canyon, and then everyone got their
own twisted pair. Now it's internet service all the way as well!

johnoder said:

Both motor and alternator / generator are HC products.

How can it be a home made set?

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Very simply...whoever assembled the M/G set used parts that just happened to be made by the same manufacturer. The motor is much newer than the generator. Holtzer-Cabot serial numbers can be found on this page: Electric motors used in American coin pianos and orchestrions
Serial No. 638722 would have been made in 1927. That generator appears to be of a much earlier vintage.
Keith

Another. Maybe "made" by the same guy!

Old Telephone Ringing Machine Holtzer Cabot Electronic Company Works Clean Marks | eBay

Looks like an alternator used by the phone company to generate the 80-90 volt AC ring voltage at the central station. It was then switched from the ring buss to which ever copper pair (phone line) needed to have a phone ring.

Bob
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