BEHOLD! The ratio transformer! - Page 1
Forum section: electronics / testgear

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: January 27, 2014, 05:16:34 pm
content: I've been looking at buying a ratio transformer for a while. I found this one on eBay earlier this morning and found the photo to be kind of funny:http://r.ebay.com/wwJ3fvThe rest of this post is just what popped into my mind after seeing it:And Tesla said, "The LORD delivered unto me six knobs of voltage division designed with the finger of God; and on them was written according to all the numbers, which the LORD spake with you in the mount out of the midst of the fire in the day of the assembly."After the full forty days, Tesla and Westinghouse came down from the mountain with the knobs of voltage: "And it came to pass, as soon as he came nigh unto the camp, that he saw the Kelvin, and the Varley: and Tesla' anger waxed hot, and he cast the knobs out of his hands, and brake them beneath the mount."

author: TerraHertz
author_rank: Super Contributor
timestamp: January 27, 2014, 11:20:17 pm
content: Hah, yeah, amusing pic.I didn't know such a thing existed. Darn, now I want one.Ebay browsing from that one led to ebay # 400653434352QuoteBecause who needs voltage regulators when you can use giant lumps of iron and filters.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: January 27, 2014, 11:56:53 pm
content: These come up from time to time on here. They are much better than a resistor divider (though for AC only, no DC) because they are based on a physical constant (number of turns) there is functionally zero drift and they can be made VERY precise.

author: lowimpedance
author_rank: Super Contributor
timestamp: January 28, 2014, 12:24:13 am
content: And when 'GOD' had finished practicing he created the DT72a 7 decade divider, or actually it was ESi come to think of it!.Gertsch made some nice stuff as did ESi. Of course cal labs also make there own too.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: January 28, 2014, 12:29:52 am
content: Quote from: lowimpedance on January 28, 2014, 12:24:13 amDidn't Gertsch make it then ESI bought out Gertsch. Then ESI was I think purchased by IET Labs.

author: mrkev
author_rank: Regular Contributor
timestamp: January 28, 2014, 12:40:47 am
content: We had something "like that"in high school. It was three phase autotransformer for 380V and about 10kW, it had big wheel which moved the carbonic collectors across the coils, was about 2m high and more than 1m in diameter... We used it to power motors... You could tell when it was swiched on (with load), even tho school had transformer from 22kV power line directly underneath it...

author: lowimpedance
author_rank: Super Contributor
timestamp: January 28, 2014, 02:24:00 am
content: Quote from: mrkev on January 28, 2014, 12:40:47 amHUH ......... not quite the sameQuote from: PedroDaGr8 on January 28, 2014, 12:29:52 amI dont believe they were related at that time, but maybe IET has aquired them since

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: January 28, 2014, 03:30:17 am
content: Quote from: lowimpedance on January 28, 2014, 12:24:13 amThe book Coaxial AC Bridges is the seminal work on the subject. A good read for anyone that wants to make AC measurements to within 10^-9 parts.