Where can I get a 3-phase AC signal generator? - Page 1
Forum section: electronics / testgear

author: Ben321
author_rank: Frequent Contributor
timestamp: October 07, 2022, 05:37:59 am
content: I know there's industrial single-phase to 3-phase converter units, that use a standard single-phase AC motor to drive a 3-phase generator. However, these are very expensive, and involve working with dangerous high voltage (single-phase motor runs on 120VAC, and the generator output is 277VAC phase-to-ground and 480VAC phase-to-phase). I also know there's cheaper and safer (low voltage 3-phase) solid-state signal generators out there, because years ago, I saw on a website that sold electronic equipment for use in schools and colleges, and they had one that just plugged into a regular 120V outlet, and the front panel of the device had 4 banana-plug sockets (one for each phase, and one for neutral) for the outpout. But for the life of me, I don't remember what website it was that was selling it, or who manufactured this solid state 3-phase AC signal generator.If anybody here knows of a lab or demonstration type solid-state 3-phase AC signal generator, that's currently being manufactured and sold, please let me know where to find it.

author: Ian.M
author_rank: Super Contributor
timestamp: October 07, 2022, 05:46:19 am
content: Any three (or more) channelAWGshould be able to output a low voltage, low power three phase signal, if set up correctly.

author: Ben321
author_rank: Frequent Contributor
timestamp: October 07, 2022, 06:31:47 am
content: Quote from: Ian.M on October 07, 2022, 05:46:19 amThat's a good idea, but I was just wondering where I could get something that could output a little more power, like for running low voltage 3-phase AC motors or low voltage light bulbs. I remember there being such a device sold on a more educational oriented science equipment website before. It output like 12v 3-phase AC for educational lab and demonstration purposes. But I can't find anything like that on the internet right now.

author: Berni
author_rank: Super Contributor
timestamp: October 07, 2022, 07:10:13 am
content: BLDC motors are actually permanent magnet synchronous 3 phase motors/generators.So just get low RPM high torque brushless motor(like used in RC cars/boats) and spin it with another mother at the desired RPM for the frequency you want.

author: JohanH
author_rank: Frequent Contributor
timestamp: October 07, 2022, 07:11:52 am
content: There are frequency converters one-phase to three-phase with adjustable output voltage. Googling gave me only this:https://www.alibaba.com/product-detail/ACSOON-AF400W-1-Phase-to-3_60439961502.html

author: 2N3055
author_rank: Super Contributor
timestamp: October 07, 2022, 07:15:21 am
content: You could get a small VFC with 3 phase output and use 3 stepdown transformers...

author: Someone
author_rank: Super Contributor
timestamp: October 07, 2022, 07:28:12 am
content: There will be a handful of companies making these things for teaching labs:http://www.didalab-didactique.fr/site/materiel/EN-produit-951.htmlhttps://infinispark.com.au/products/portaphase/you will not like the prices

author: Jeroen3
author_rank: Super Contributor
timestamp: October 07, 2022, 07:32:56 am
content: Three of these should do it:ITECH IT-M7700Or if you need lower voltages, just get three waveform generators and sync them up.

author: tautech
author_rank: Super Contributor
timestamp: October 07, 2022, 07:39:26 am
content: Quote from: Jeroen3 on October 07, 2022, 07:32:56 am2x two channel AWG's can easy do this if they have 2 features, syncandphase shifting.

author: jonpaul
author_rank: Super Contributor
timestamp: October 07, 2022, 07:58:10 am
content: Voutput? KVA? type of load?Jon

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: October 07, 2022, 10:55:28 am
content: have a look here:https://www.leybold-shop.com/three-phase-generator-725721.html

author: Martin72
author_rank: Super Contributor
timestamp: October 07, 2022, 11:46:05 pm
content: I think with the last post the question was answered.Although it could be interesting to check if this :QuoteWouldn´t be a cheaper solution.Apart from this, 2 decades ago we were in the need for a AC source with three phases and frequencies between 2...4khz, voltages up to 140Vrms.No solution on the market...what to do...We´ve modified a sinewave-generation pcb* in such manner to get the frequencies up to 4khz.And then feeding the three-phase sinewaves into ordinary audioamplifiers, in this case PA amplifiers.Got a huge advantage, outputfilters are not needed.*)3-phase sinewaves generated by a PLD, Eprom, 8-Bit ADCs and U/I conversion/filtering.

author: artag
author_rank: Super Contributor
timestamp: October 08, 2022, 12:37:04 am
content: It might have been made by FeedbackThey used to produce a lot of equipment for educational use, and a 3-phase low power system would be suitable for running an ac servoHere's a typical bit of Feedback kit :https://www.ebay.co.uk/itm/185508991896- they very often used that blue case.And here's a very education-specific piecehttps://www.ebay.co.uk/itm/154557379115

author: artag
author_rank: Super Contributor
timestamp: October 08, 2022, 12:39:36 am
content: Quote from: Berni on October 07, 2022, 07:10:13 amYou could also use a BLDC sensorless driver. These are available at very low cost and used to run drone motors. Some even have open software.

author: bdunham7
author_rank: Super Contributor
timestamp: October 08, 2022, 01:03:50 am
content: Probably the cheapest and easiest way (other than an expensive dedicated device) to bodge together some moderate-power three-phase is the get 2 FY6900 AWGs and 2 FPA2000- series amplifiers from eBay or Aliexpress. That will give you four channels of arbitrary output and up to 50W/channel, 25Vrms@ 2A.

author: Ben321
author_rank: Frequent Contributor
timestamp: October 08, 2022, 06:41:44 am
content: Quote from: Someone on October 07, 2022, 07:28:12 amThis is the best answer!Specifically the webpagehttp://www.didalab-didactique.fr/site/materiel/EN-produit-951.htmlshows a device that appears to be the exact, or almost exact product I was thinking of when I originally started this thread. The problem though is I don't know what the price is. They appear to not list the price. The second problem is that it appears to use a European plug (which also means it runs on 240V, not 120V, and I live in the US with 120V).I'm pretty sure the one I remember seeing years ago was one meant for US use, and thus would have had a US style power plug, and be designed to run on 120V AC. Is anybody here aware of a US version of this product?

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: October 10, 2022, 12:44:48 am
content: Quote from: Ian.M on October 07, 2022, 05:46:19 amYep, works well. Just need power amplifiers to get it up to something useful.

author: Jester
author_rank: Frequent Contributor
timestamp: October 10, 2022, 01:14:40 am
content: Manta TestDoble EngineeringOmicronYou will need a suitcase full of money

author: Ben321
author_rank: Frequent Contributor
timestamp: October 13, 2022, 08:03:24 am
content: Quote from: Ground_Loop on October 10, 2022, 12:44:48 amWhere would you get such power amplifiers?

author: Jester
author_rank: Frequent Contributor
timestamp: October 13, 2022, 01:02:18 pm
content: Quote from: Ben321 on October 13, 2022, 08:03:24 amKepcoManta TestDoble EngineeringOmicronThey have amplifiers that output up to 300V, 180A, 2400VA. They are stable into some pretty nasty loadsThe didalab looks like it only outputs 24VThere is areallyold Manta 1710 kit on ebay for $4500 right now (3x 400VA current, 3x150VA voltage), good luck if it fails Manta was purchased by Doble recently so the 1710 is no longer serviced. They sold for about $40-50k way back then, so $4500 is pretty cheap

author: Stray Electron
author_rank: Super Contributor
timestamp: October 13, 2022, 01:53:22 pm
content: Ben,You don't show where you're from but take a look at some of the Elgar AC Power Sources. These generally sell cheaply because very few people understand them or have a need for one. They are available with single phase or three phase outputs (and with a single phase input!) and up to 260 volts. Depending on the plugin, they're either fixed frequency or can be variable frequency (up to 10khz IIRC). The output voltage is also variable. The 251 models can output up to 250 VA and the 501 models up to 500 VA and there are larger models. Be warned though that these are beasts! They're a full rack mount size and even the lightest one weighs nearly 100 pounds and the biggest ones are MUCH bigger and heavier. Brochures, installation and operator manuals, repair info and other docs are available on line. I currently have five of these. I was able to get several of mine from local surplus dealers for a song since they're too heavy to ship with major headaches and no one else wanted them so I got two for scrap metal prices and the others were just given to me.If you're in the US or other major country, go on E-bay and see what's available. Then search for the nearest to you. If you can go pick one up in person you can probably get one for < $100.Also be aware that most dealers list the specification of THE particular unit that they're trying to sell. Often a fixed frequency unit or a single phase output only model. You need to look at the factory specs of the Power Source to see what their actual capabilities are and also look and the specs of the various plug ins that can be used with the Power Source.

author: artag
author_rank: Super Contributor
timestamp: October 13, 2022, 04:07:18 pm
content: I have a single-phase mains source by Chroma that allows adjustment of frequency and voltage.They also do a 3-phase source :https://www.chromausa.com/product/3-phase-programmable-ac-source-61700/Warning : I have found Chroma unhelpful regarding information about their older products.

author: Stray Electron
author_rank: Super Contributor
timestamp: October 13, 2022, 04:41:19 pm
content: I've never had to contact Elgar so I don't know how helpful they would be but I've played with about 10 or 12 of their units that were surplused and every one of them worked and I've been able to find manuals online for everything that I've looked for. Their stuff seems to be built like a brick outhouse and just never fails. I've seen other brands of AC Power Sources (I have a Pacific Scientific) but they're harder to find and there doesn't seem to be much documentation on them so I just stick to the Elgar brand and recommend them.If you've got the room to keep one; the variable voltage, variable frequency, and up to three output phases, AC sources can be dammed handy at times!If anyone is looking for one, there's currently one on that auction site that the seller is asking $160 for. He says that it doesn't work but the plug in that he has in it is meant to be driven by another unit so that's probably why it isn't working. I expect someone could buy it for a lot less than the asking price, especially if they could pick it up in person and save the seller the headache of packing and shipping it.

author: james_s
author_rank: Super Contributor
timestamp: October 13, 2022, 05:15:46 pm
content: I have a similar unit made by California Instruments. Mine is only single phase but they made 3 phase versions too. They are essentially a big linear audio amplifier with a step-up transformer on the output. The thing is very heavy and makes a lot of noise but it's handy to have around at times.

author: rvalente
author_rank: Frequent Contributor
timestamp: October 14, 2022, 05:22:03 pm
content: As usualhttp://feeltech.net/is down, but IRC they have a triple output AWG FY8300 and FY8400

author: langwadt
author_rank: Super Contributor
timestamp: October 14, 2022, 05:54:47 pm
content: Quote from: james_s on October 13, 2022, 05:15:46 pmif using step-up transformers you could get a ways with just a stereo amplifier, because the last phase can be made from the two other with just add and invert using a transformer