Re: Step-down Transformer, AVR thread (and Variac)

Hanep!

May selector para variable voltages? The way it looks, bullet proof.

Yes Bro Ding it's variable from 0 to 240V. I did set the voltage output to 120V as in the Bosch 4100 nameplate.

Re: Step-down Transformer, AVR thread (and Variac)

This is what I got to power my Bosch 4100 table saw. Surplus Variable Transformer 3KVA.

Yey, another variac! Looks in pristine condition and well made too. You may have googled around, there really is nothing that will break on these except maybe some wear on the carbon brush. Though it will not provide faulty ground isolation like a true transformer, I've used it to step down voltages and even slowing down power tools (with universal motors) that has no fancy electronics. Great thing to have.

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After almost a century of a productive life in this world, i learned this month that Father Georg have passed away a couple of years back. I wouldn't be fascinated with variacs if it weren't for him. He and the well equipped physics lab he built sure made for good education. (There's nothing like making chlorine gas for yourself -and having a runny nose cured after inadvertedly sniffing some- with some flasks aside from just reading up on it.) But back then I remember NOT appreciating lugging a heavy variac with 30 meters of electrical wire for an extenstion cord!

Not much info about him floating in the internet except for a short wiki http://de.wikipedia.org/wiki/Georg_Schwarz_%28Geistlicher%29

Re: Step-down Transformer, AVR thread (and Variac)

I know German Physicist Father George. Our Rector in Don Bosco Tarlac during my elementary days. Your description of him fits my memory well. I had the chance to study under his tutelage as a young boy back then. May he Rest in Peace.

Here Owyn ... I shot a couple more pics of the variac. I haven't wired it up properly yet but have tested and I'm quite happy with it. My US model power tools are happier still running at 120V on the dot now.

Re: Step-down Transformer, AVR thread (and Variac)

Hey Owyn, was actually trying to get in touch with you prior to the purchase of that variac.... Where have you been? Married? Kids? Hehehe
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Re: Step-down Transformer, AVR thread (and Variac)

I know German Physicist Father George. Our Rector in Don Bosco Tarlac during my elementary days. Your description of him fits my memory well. I had the chance to study under his tutelage as a young boy back then. May he Rest in Peace.

Hey Guys, I am a Bosconian too, DBTI Makati. Small world.:)

I too have a Variac from our former AVR /Transformer business. We had to shut it down due to the very low price of our Asian contemporaries.

Re: Step-down Transformer, AVR thread (and Variac)

Hey Owyn, was actually trying to get in touch with you prior to the purchase of that variac.... Where have you been? Married? Kids? Hehehe
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Having a kid sure is a joy and uh... a challenge Timb. Overall i'm glad i got dragged into this phase of life by a gal who is now my wife. Kaya Moji, tsaka mga iba dyan, ingat ingat lang kayo, enjoy your time... ...di nyo rin alam kung kelan kayo mapapalakad sa simbahan hehe.

Had i known i'll be going down this path, maybe i should have started earlier AND acquired more tools prenup.

Despite the lack of posts, I frequently log-on here on PHM and cab1net weekly so i can always be reached by a PM =).

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I didn't go on much about Herr Georg Schwarz but i had a feeling that a lot of people grew up with some technical inclination (inclination! just be curious and try things out!) because of the likes of him. He was already rather frail when i left canblubang in '03 but his work ethic was impressive, he'd be on the lab (i.e his workshop) all alone till around 10pm. I think he made sure a system was in place when he's gone but when i went back there this month, the place definitely isn't the same without the man.

Technology is great but I think i want my kid to be playing with legos while in elementary, maybe messing with breadboards in HS instead of looking at touchscreens for a hobby.

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Judging from the Kaizen/5s motivated labeling, that variac must have come from a place that closed down. (Sad that no new manufacturing plant goes here, current numbers of operating ones just shrink.) Japanese operations tend to patronize japanese equipment and supplies down to the electrical tape.

I can't see if you did JayL, but Crimped style ring terminals would make for a strong, sound electrical connection. (Hmmm, i should follow my own advice!)

Re: Step-down Transformer, AVR thread (and Variac)

Variac i got is a 3KVA one that i had to put an enclosure on because it was meant to be a part of a bigger electric assembly. Haven't gotten around to replacing the ghetto allen key for the dial. (but it's safe and insulated.)

Obviously, a variac ain't going to fit inside a router unlike a triac will but it's the better universal motor "speed controller" from what i read and know. I just wing it and stay from 180-220v for 220v power tools. What the ampere meter tells us is that power tools have fantastic inrush (startup) current as it tries to bring up to speed the whole commutator (plus collet and bit) from standing still. When it has the least bit of inertia, the ammeter doesn't whiplash so much.
http://www.youtube.com/watch?v=Rm64HwnHRy4

Like Jayl, i use the variac as a "step down" transformer for 110V induction motors like in a bench grinder. Trouble with 110volt tools is that to achieve the same work (power measured in watts,) it'll have to draw a lot more amps (which will require bigger wiring among other stuff.) Watts = Voltage X Amperes.
http://www.youtube.com/watch?v=ew_qCqN9aPM

With the switch flipped, the induction motor draws so much crazy current just to turn the massive grinder stones from zero to 3600 revolutions per minute. It then rests to less than an amp doing nothing, only drawing higher current if it's challenged (like feeding a workpiece.) Variac says it eats 2 amps on regular work but the name plate says you can demand up to 6.5 amps without bogging it down.

Re: Step-down Transformer, AVR thread (and Variac)

Hey Guys, I am a Bosconian too, DBTI Makati. Small world.:)

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Glad to know this Bro Willy. 🙂

@Owyn

Yes bro I will wire it up properly when I get some connectors. So far I've tested the variac and am very happy with the performance.

Does Ace have those connectors packaged in different sizes. I always forget to order in advance and am so disappointed when time like this happens and I don't have it on stock in the shop.