8mm Forum: ST-800 voltage?

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Topic: ST-800 voltage?

Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008

posted November 28, 2013 11:57 PM

I have this ST-800 I bought inJapan and was wondering if anyone had an idea about the voltage? Specifically, if you look at the photo, you will see a brown wire which comes from the mains, is plugged into P2. Next to that is an empty tab labelled P1. I am wondering if someone who has a US bought unit has the same markings and where is the brown wire connected? My guess is that P1 is 115v and P2 is 100v for Japan but I don't want to just switch it without some sort of confirmation.
Thanks to Winbert for bringing up this possibility.

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007

posted November 29, 2013 02:46 PM

Have you got a Variac and a AC volt-meter?
If so, you could feed a small voltage in and see what you get out.

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Maurice

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 29, 2013 02:50 PM

When I am past the Thanksgiving weekend I can check my machine out and let you know what I see.

-dumping it on the dining room table and taking the back cover off is frowned upon with company in the house...for some reason!

If you are running the machine of 100VAC now, and put a voltmeter between P1 and AC neutral, you will see 115VAC there if that is the voltage that terminal is set up for.

(Mind your connections, and your fingers!}

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All I ask is a wide screen and a projector to light her by...

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Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008

posted November 29, 2013 05:04 PM

I'm pretty good with most electronics but I guess I just don't fully understand transformers.
So, if I am running the machine at 100v albeit through my voltage converter, I can see voltage in that other tab? Perhaps 115?
Just in terms of what I think I know, I think of those tabs as input and measurable voltage would be at the other end...but like I said, I don't fully understand. I'll try that experiment later today.
Thanks!

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 29, 2013 06:56 PM

Basically a transformer is a bunch of coils of wire on a core sharing the same magnetic field: the different voltages are because of different numbers of turns for each voltage. The number of volts per turn is the same for all of them.

What this means is if (for example) you have a hundred turns on the 100V winding, you will have 15 more turns in series for the 115V winding. This way whatever the number of turns is on the output winding the voltage will be correct because that volt per turn ratio is the same in both cases.

It also means that because you have that 100 volts already, the extra 15 will show up too whether you are using them or not.

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All I ask is a wide screen and a projector to light her by...

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John Capazzo
Master Film Handler

Posts: 421
From: Hillside, NJ USA
Registered: Jan 2004

posted November 29, 2013 09:04 PM

Steve is correct; and if you've purchased it from someone in Japan, more than likely a 220v machine. Some had a glass round window to indicate it was 220v. Also, check the inlet for the power cord. They used two round pins as opposed to USA and Canadian models which had three round pins.

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"the image is about 30 feet ahead of us."

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Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008

posted November 29, 2013 09:41 PM

Well, I tested the other tab but only got a reading of 93 volts. Not sure what that means except that I guess I'll continue to use my converter.
I go to Japan every year and I picked it up while I was there. It does have the two pin plug but definitely is 100 volts. Not only does it say so on the machine but I believe all consumer electronics run 100v. I would imagine there are 220v industrial applications just like here, but the average plug in the wall is always 100v as far as I've seen.

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Dominique De Bast
Film God

Posts: 4486
From: Brussels, Belgium
Registered: Jun 2013

posted November 29, 2013 10:12 PM

I think that they use(d ?) 100 volts in Japan as I have a Japanese Elmo at this voltage.

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Dominique

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 30, 2013 12:26 AM

Your 93V means that terminal isn't what we hoped it is. What it really is is another story.

So your ST-800 is running with a two prong inlet? This is actually semi-scary because this means your chassis is ungrounded. If a live conductor detaches inside and touches the frame, the whole thing becomes live and a shock hazard.

The immediate action is to avoid using this projector while in the bathtub!

US spec ST-800s have three prongs in the inlet and their frame grounded.

(Actually a great many projectors are two prong, it's just not the optimum choice!)

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All I ask is a wide screen and a projector to light her by...

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Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008

posted November 30, 2013 12:41 AM

I wonder what that other story could be?
Not a big deal, but I was hoping to eliminate the converter.
And I'm not overly concerned with the ungrounded chassis. Unless I get invaded by little wire detaching gremlins, I don't think it will be an issue. (I hope!) In the meantime I will certainly not screen films while in the tub.
Thanks for all the help and good advice.

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007

posted November 30, 2013 03:53 AM

Don't forget about the differing mains frequencies in Japan. The following guide will help about the voltage and frequencies in Japan.
http://www.japan-guide.com/e/e2225.html

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Maurice

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008

posted November 30, 2013 05:16 AM

Frequency shouldn't be a problem as this machine, like the ST600, has a DC motor electronically controlled for speed.
Martin

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Retired TV Service Engineer
Ongoing interest in Telecine....

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