AvSat44 Posted April 7, 2022 Posted April 7, 2022 A Friend, who also happens to be an SNA member, purchased this device today. It is a fully automatic AC voltage regulator which can be set for an output of 110v or 220v AC. It's rated at 500 watts so its pretty grunty. The regulator is partly solid state but because of its rating, uses a motor driven rheostat (a little like the ones in a Variac) to constantly adjust the voltage. It's a bit like a high end step down transformer I guess. He was pretty excited as he thought that this could be used to run (on the 110 volt setting) Japanese 100v gear. We then asked each other the question. It puts out a regulated 110v so is that going to be an issue with 100v equipment? We are hoping that he hasn't just bought a really flash display piece.
RoHo Posted April 8, 2022 Posted April 8, 2022 Any idea what the tolerance of Japanese 100V mains is? If its +/- 10% then you would think Japanese gear would be designed to be OK with that ie 90-110V would be acceptable.
muon* Posted April 8, 2022 Posted April 8, 2022 (edited) What input from the wall is this thing rated for? Is it 240? Edit: OK I see it is switchable just currently on the wrong setting. Edited April 8, 2022 by muon*
xlr8or Posted April 8, 2022 Posted April 8, 2022 (edited) On 07/04/2022 at 8:59 PM, AvSat44 said: We then asked each other the question. It puts out a regulated 110v so is that going to be an issue with 100v equipment? Yes, confirming it will. You need to use 100v or 105v maximum only if the PT primary has the second 105v setting. Do not use 110v or higher. From first hand experience, I've seen what happens if you do. The big power filtration caps will fail. Also, the unit your friend has acquired looks to be both a step down and step up transformer. Presumably if used in AU with 240v AC mains, you would only expect 220v out of the unit. I don't think the unit is designed to give 110v for our AC mains. Edit: Found this video for another STAC model. Applying a correction to my initial post above. It appears you can get both 220v and 110v at 240V AC mains. Fuse is rated to 250V. Hopefully, line voltage doesn't exceed that. Edited April 8, 2022 by xlr8or 1
muon* Posted April 8, 2022 Posted April 8, 2022 (edited) ............ Eh, tis late, I'm confused. Edited April 8, 2022 by muon*
bob_m_54 Posted April 9, 2022 Posted April 9, 2022 (edited) On 07/04/2022 at 8:59 PM, AvSat44 said: The regulator is partly solid state but because of its rating, uses a motor driven rheostat (a little like the ones in a Variac) to constantly adjust the voltage. It looks like a motor driven variac (variable transformer), not a rheostat. So if you just want to use it as a stepdown tranformer, you could disconnect the motor drive and manually set the variac for 100V. Would have been easier just buying a step down transformer though.. Edit: what does the pot adjust? if it's voltage, then you may be able to set the desired o/p voltage that way. But it could be sensitivity too? Edited April 9, 2022 by bob_m_54
AvSat44 Posted April 9, 2022 Author Posted April 9, 2022 Ah yes, it would have been easier to buy a stepdown transformer from a local supplier. However, he bought it more as a novelty and on the off chance that it would do the job, he handed over the cash. He was otherwise going to just park it on the shelf in the man cave. The purchase price was $45.00 and a 120 watt cheapy from Jaycar was priced at $119.00 and come to think of it they only step down to 115v. So to the shelf it is.
muon* Posted April 9, 2022 Posted April 9, 2022 For decent step downs you can't go past Tortech in Sydney. 1
bob_m_54 Posted April 9, 2022 Posted April 9, 2022 12 hours ago, AvSat44 said: Ah yes, it would have been easier to buy a stepdown transformer from a local supplier. However, he bought it more as a novelty and on the off chance that it would do the job, he handed over the cash. He was otherwise going to just park it on the shelf in the man cave. The purchase price was $45.00 and a 120 watt cheapy from Jaycar was priced at $119.00 and come to think of it they only step down to 115v. So to the shelf it is. So did you work out what the pots (I see there are two visible) actually adjust? and like I said in my previous post, you could still use it as a manually set Variac, to step the voltage down.
xlr8or Posted April 9, 2022 Posted April 9, 2022 7 hours ago, bob_m_54 said: So did you work out what the pots (I see there are two visible) actually adjust? and like I said in my previous post, you could still use it as a manually set Variac, to step the voltage down. I found the video below which at the 32 min. mark shows the pot being adjusted on the main controller board to adjust the output voltage. Range is dependent on input voltage and range on trim pot. The other trim pot just above the unit's meter I suspect is for calibrating the needle to align to the output value. https://m.youtube.com/watch?v=s1A5lwMSUrU
bob_m_54 Posted April 10, 2022 Posted April 10, 2022 3 hours ago, xlr8or said: I found the video below which at the 32 min. mark shows the pot being adjusted on the main controller board to adjust the output voltage. Range is dependent on input voltage and range on trim pot. The other trim pot just above the unit's meter I suspect is for calibrating the needle to align to the output value. https://m.youtube.com/watch?v=s1A5lwMSUrU haha, I couldn't be bothered watching when I first saw that video, bit of a language barrier. So thanks for that. It looks like the bottom end of the Variac was giving him 104VAC, so depending how the input voltage and Variac in the OPs unit goes, it might be able to get low enough....... or just miss out LOL.. Worth a try though.. 1
AvSat44 Posted April 10, 2022 Author Posted April 10, 2022 According to my friend, this unit has already been relegated to the shelf. Seems like Tortech are the way to go. 2
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