Phase shifting?

I've been considering building my own ground penetrating radar unit rather than pay outrageous rental fees and mind boggling full prices and I keep coming back to the same problem: time of flight is haaaard. My most recent thoughts on how to go about collecting that data would be to use 2 clocks/crystals that are offset from each other by fractions of a percent(one would be straight from a rubidium standard, and the other from a frequency multiplier). One would be in charge of timing the emitter and the other for timing the receiver. This is the part where I make tons of assumptions about things I know nothing about, so correct me if I'm wrong.      The emitter is running at f1 and it emits a short pulse.      The receiver is running at f2 and collects data as fast as it can until the reflections dissipate.      The emitter pulses again      The receiver, due to the f1:f2 phase shift, is offset by a tiny amount and again collects data as fast as it can. This cycle repeats until the collective phase offsets brings it back around, building the image . My thinking is that this shift, given the time to cycle around, could provide data that is functionally in the range hundreds of GHz, provided the target doesn't move(which at milliseconds per dataset, is functionally true). Could this work?

Question by The Ideanator   |  last reply


3-Phase Power? Answered

I already asked a question about three-phase power but my results only confirmed what I thought.  I don't understand how a MOTOR can run at 230v with three phases,  how do they rate power with these I guess.  230v outlets have three prongs, I think two are connected to the generator through power transmission lines, and one is a ground.  If this is wrong were do they get 230v because, if I am wrong all three wires connect to generator coils.  This would add up to 345v.  But to get 230v it would only be two phases.  Then it can also run on 480v, how in the world do you get to 480v.  Please help me with this.

Question by jj.inc   |  last reply


Single and Triple Phase? Answered

Ok, so I thought I knew how the power phases worked and then I got myself confused.  Our house has three phases and it offers power at 120v, 240v, and 480v (or at least can I think).  All three wires on the power poles go to transformers and then to the house and so on.  I have seen houses that just use one which I think I understand unless they try to get a dryer then what do they do.  I am going to ask a little more than phases here to just to make sure I get this.  In you wall outlet one is from a line on the power poles correct? and the other is ground which works because at the generator site the electricity is grounded on one side.  Now before I get ahead of myself, how can there be single and triple phases in a 120v outlet and what exactly are they.  Now, at a 240v outlet you have two hot wires coming from the power lines right, and then one ground.  Now I think all the lines on the poles come down to 120v, so how do you get 480v from three 120v lines.  3*120 does not equal 480v.  I am confused.  Also will having triple and single phase even effect how things work.  Like we have a 120v single phase compressor and it works just fine at our triple phase hose.  So it doesn't really make any sense at all.

Question by jj.inc   |  last reply


3 Phase supply

What will be configuration to supply 3 Phase 460 V power into these strings having voltage range as shows in the pics. It can be either star, delta etc configuration. It should be balanced. Answer will be highly appreciated.

Question by tverma95   |  last reply


3 phase to 240v?

I have a sauna heater Voltage: 380~400 V 3N~ is there any well of wiring it up to 240v 

Question by gary.beecroft.92   |  last reply


Creating a "dome" of sound using speaker phase?

Ok so, I want to install some kickass speakers into my pergola, but I don't want to annoy my neighbours with unwanted bass at 3 in the morning. Is it possible to place out of phase subs hidden around the pergola (a fair distance away) to cancel out the bass frequencies and create a sort of "dome" of sound?

Question by cooper.wolfden   |  last reply


Active mixer and 180 degrees out of phase question? Answered

Hello , i want to make a simple active mixer to place in front of the power amp. I read some documents about active op-amp mixer.And they said : "Any signal entering the inverting input of the op-amp will appear at the output but it will be 180 degrees out of phase.If the output of the first op-amp were recombined with one of the other signals at a later stage it would cancel out rather than mix. So we have to re-invert the phase with yet another op-amp." and the schematic should like figure 1 to re-invert the signal . But if i use the the mixer to direct feed input of power amp , can i use the schematic like figure 2(w/o re-invert the signal) ??? Thanks in advance! Sorry for my bad English!

Question by login721   |  last reply


Need help with a Single Phase 1Hp dual voltage reversible motor. How to figure out which wire is which. Answered

My dad gave me an old but awesome table saw years ago and told me the motor turned the wrong way. Nomenclature tag states its a GE CAP motor (aren't they all?). I do have a tag showing the possible wiring connections. Shows it has NO overload protection. What I DON'T have are marked wires. I have 2 wires connected to L1. I have 1 wire connected to Neutral. I have 3 wires tied together. Any info I have found indicates this is wired for high voltage. I would like to run it on low voltage. I also don't know the rotation. So far all the wiring info assumes you have marked wires. I cannot find any info as to which wire goes to which coil, etc. How can I identify each wire so I don't "let the smoke out". I learned years ago motors run on smoke. Once you let the smoke out, they don't work anymore. Lot's of sentimental as well as practical value at stake here, not to mention a GREAT learning opportunity (as well as teaching).

Question by burnerjack01   |  last reply



Control rotation 3 phase mortor with visual c ??

Hello everyone. i have one project to control the rotation 3 phase motor with visual C. But i don't know how to do that. anyone who know tell me how to do that please :)

Question by pfromthailand   |  last reply


how do I re-wrapped three-phase motors?

I needs schematic 3 phase AC motor

Question by dwiputra   |  last reply


Do I need to invert phase a second time? Answered

I'm building a guitar pedal and I am inverting phase with the initial buffer (TL072). I am then splitting the signal into two parts, dry (no effect) and wet (effect). Each of these will be output as separate channels (left and right) and not mixed back to mono. I plan to send each channel through its own 386 amplifier chip to boost it to a level suitable for headphones. So, what I am wondering, is, should I use the 386 to invert the phase a second time back to normal? Or should I use an op amp at unity gain to do that before I send it to the 386? Or does it not matter if I am not mixing the two signals back to mono?

Question by randofo   |  last reply


can you convert single phase to three phase easily?

I have a three phase lathe, but only single phase in my shop. Is there a way to easily convert single phase to three phase?

Question by qparker   |  last reply


230V 3 Phase Motor on 240V Single Phase Supply

Hi, I am a ME with very limited knowledge on electrical side of the world. I have ordered a electric motor from Germany with 240 V assuming it will be single phase. The motor has rocked up with 230 V winding but 3phase connections. Is there any chance I can connect this motor to our single phase supply???  Any device which will help to use this motor. Please help.

Question by NasirA9   |  last reply


What is a three phase supply?

Question by AnkitY20   |  last reply


AC Power Phase Control?

Hello, Can we use AC phase power control Solid State Relay to control the speed of single phase Induction motor, Using PWM as input to the Relay and the output of relay connected to Induction motor, The motor runs at 220v AC,50Hz,55Watt.

Question by KaroonjharN   |  last reply


Phase Cancellation to Prevent Feedback

The Grateful Dead's wall of sound prevented feed back by having two mics for each vocalist with one of the mics 180° out of phase of the other. Then mixing both mics on the same channel. So the only information that wasn't canceled was the voice.  This gave me an idea. I took a handset and added a mic facing backward from the existing mic. Then wired the second mic out of phase. Apparently there's more to it electrically then just wiring the other mic backwards because the handset went dead. Is this possible with just parts salvaged from old phone equipment?

Topic by AJRimmer   |  last reply


3 Phase inverter explanation?

I am trying to make sense of how to create a simple 3 phase inverter, but the design I have found requires the use of a PIC micro controller for pulsed width modulation to control the 3 half inverters in the image below. I do not have experience with this specific type of micro controller and am unable to find a simple explanation of how to set it up to do this, except how to connect it to the basic circuit at the transistor bases. Would anyone be able to explain to me how to wire/program/control frequency with the pic micro controller or an alternative method that would yield 3 phase power (0-120-240) because the manual and this page have be very very hard to understand to a beginner. I do not need any sort of feedback from the motor because the load will be constant and relatively small, and will most likely run it either at a constant or if easily doable linearly increasing frequency. Can someone PLEASE give me a good simple set of instructions on how to either replace this micro controller with something simpler or wire/program it to do this? Thanks!

Question by amelius   |  last reply


K'nex .... It's just a Phase ........

Don't you agree Knex is just a phase. Its like when most people come on Instructables, the majority of the younger half of the community on here come across the site because of K'nex Guns. I'm not saying thats a bad thing, but you will eventually get bored of homemade guns that are made of plastic that shoot about 60 feet max. Trust me anyone saying that their/ or a particular model can shoot ranges of up to 200 or 300 feet is BullSh*ting. And also the originality of the guns posted on this site is terrible. You will get like the same type of gun or mechanism or whatever, posted more than a hundred times. However there are some "original" K'nex models or guns that get uploaded onto Instructables , and for the very few that do I praise the designers! Also I find the majority of the knex "clan" have appalling spelling. I mean for God Sakes there is a SpellChecker! The Knexers on this site either grow out of knex and move on to the better builds, or just stop using this site all together. There are very few "older ones" that stay and do knex. Anyway there's my 2 cents. The K'nex Clan is dying. I assure you, you will grow out of knex! I have and yay! I have become a "normie". There are many other great builds on instructables to enjoy.

Topic by Baron A   |  last reply


400 Volts 3 phase to 240 Volts Single phase Motor

Hello we bought a cutter from Europe.  It came with 400V 0.75W  3 phase  motor. The motor has leads W2, U2, V2 U1,V1, W1 To convert to the 240 V single phase we jumped (W2,U1), (U2, V1), (V2,W1). We also put 50uf capacitor between (W2,U1), and (V2,W1) .See attached pictures. However the motor starts and spins for about 5mins then it trips the breaker. The motor heats up . Voltage reading Between (W2,U1) and (U2, V1) =240v Between (W2,U1) and (V2,W1) = 370v Between (U2, V1) and (V2,W1) =240v We thought  (W2,U1) and (V2,W1) = 370v was little high. Also the resistance between winding W1W2 is 36 ohms, U1U2 20 ohms, V1V2 20ohms Can someone help? I will really appreciate you help

Topic by ngong123   |  last reply


3 phase AC wind generators, turbines, grid tie connected with NO battery

I have a number of 3 phase ac motors with fans on them from a large commercial greenhouse. If I put them out in the wind they spin the motor and put out 3 phase ac. I would like to know how to connect the 3 phase ac from them to grid tie with NO batteries. 

Question by Kbuchner   |  last reply


Cable tester? xlr, jack, phono etc

It looks pretty simple: http://www.studiospares.com/test-gear/studiospares-ultimate-cable-tester/invt/458260/ i was wondering whether anyone could help me with how i would go about building one of these from scratch within a hobby box? i have components (sockets and plugs, veriboard etc) but i've never designed a circuit before so any idea would be great! im thinking two rows of LEDs that match pins 1 to 1, 2 to 2, and 3 to 3 at each end of the cable being tested (maybe 4 and 5 too) refering to tip, ring sleeve on jacks, centre pin and ground sheath on phono, and pins 1, 2, 3 on xlrs. any schematics/idea please! take a look at the link for a better idea. LEDs to indicate shorts and phase switch would be cool too.

Question by jamesjamesjames   |  last reply


Help with a one phase induction motor?

I am trying to repair a bandsaw that my dad had he recntly had a stroke and he can not remember how to wire the switch back on to the motor. It is a old Kff  Single phase 110 v motor type km if u need any information to help me ask plz I can get all of the information off the motor I just need help wiring it.

Question by benton23   |  last reply


How can I find new driver boards for my 5-phase motors?

I will try to summarize the problem: 1. I have a CNC mill sitting in my garage that won't work because the whole control unit including the motor driver boards is shot. 2. I can't buy new driver boards because I don't know what spec to buy 3. I don't know which spec to buy because I am not an expert on 5-phase stepper motors and don't know how to judge / measure / test them to find their spec. So the CNC mill is of type EMCO F1P (1984), and it looks like this (actual photos of the unit). The control box that comes with it houses an awesome (for the time) integrated computer based on intel x86 chips to convert G-Code into movement. I had fun digging around inside it and here are some details about that journey. Unfortunately its from 1984 and in deteriorating shape. After being adamant for years, I have since given up restoring the control, and the current plan is to simply focus on the the machine itself with motors, which luckily is in a much better shape. This means that I will buy new motor driver boards to drive the existing steppers and get a LinuxCNC kind of control to control them. It turns out that finding a 5-phase step driver was much harder than I first anticipated. It doesn't help that the motors are without a spec. I asked a question on the ee stack site previously for finding the specs for my motor here but I didn't get any meaningful answers. I also blogged about this with lots of pictures here. So to sum it all up, any help/advice is welcome on the following:  + How to measure/test the motors to find their specs and hopefully a matching driver board  + Which brand of board is good/bad/cheap etc.  + What to look out for that I would not think of as a beginner PS: I know I could replace the motors with cheap Chinese 2-pole ones and be on my way, but I really want to do this the right way, and maybe learn something underway!

Question by lennartr2   |  last reply


I need to know how to wire a 3 phase motor to put out three phase current by running it off a single phase motor .?

I used to run three phase machines by wiring a separate three phase motor to the machine motor while spinning the motor with a single phase motor I know this sounds strange but when you can't get three phase to your shop need to improvise. This was common in country side barns in my neck of the woods back in the 70's. Thanks Nick

Question by nickitzi   |  last reply


How to rewire from a three phase motor to a 240 volt single phase motor.

I am replacing a  40 year old three phase motor with a 240 volt single phase motor. The three wires are all black and not coded in any way. How do I measure with a voltmeter? I assume one wire is neutral, but which one? Thanks.

Question by beachbum2006   |  last reply


soft start and speed control for single phase induction motor 1hp or less

hello i am oghenevwogaga izoma a diploma student i have been given a final year project of which i am to provide a speed control and also a soft start for a single phase induction motor No specifications given, i am to do the research on my own and come up with everything. please i need help and i am also running out of time. Motor specification not more than 1hp

Topic by oghenevwogaga 


so i want to build a switch that reverses the phase of the signal in a humbucking guitar pickup will this drawing work ?

The thick black wire is the sheild the small black wires and grey wire are left alone as decribed in the instuctions i got with it

Question by fastcar123   |  last reply


working with relays and arduino

I am doing a project in which i need to switch 3 phase induction motor( star connected ) using relays one for each phase and 3 phase voltage in our country is 415v( phase to phase). so my question is can I use relay of  rating 250 volts 5 amps one across each phase and 1 phase supply in our country is 230v .

Question by nanu146   |  last reply



How to measure open loop H(s)? Answered

When designing constant current linear dummy loads, and when I was (attempting) to design a really nice linear power supply with op amps and pass transistors, I consistently run into the devil of the circuits that incorporate feedback. INSTABILITY! Especially if I use fast op amps, or MOSFETs, etc. My understanding as to why this happens is because I still have some positive gain at the point at the frequencies where signal the total loop has that dreaded -180 degree phase (gain margin) and then where the gain is unity and phase is at -180, again allowing that frequency component to be successively amplified (or never attenuated) as that wave whirls around the loop. However, with op amp circuits, how am I supposed to get an accurate open loop measurement, when the DC gain is so stupidly high the input to an op amp is essentially a comparator? http://www.ti.com/lit/an/snva364a/snva364a.pdf This article suggests whacking in a 20 ohm resistor and injecting a signal into it, and measuring the voltage on either side of it (?) How is this supposed to work? Is there a better method in something like LTspice?

Question by -max-   |  last reply


single phase ,brushless direct current motor.

Does anyone have the schematics for a VERY SIMPLE, (LIKE ME) single phase brushless DC motor.

Question by ianrbell   |  last reply


Is there a guide to building a 3-phase AC welder?

I was looking through the MANY guides on the web for weldernators and I'm in the midst of putting it together. It suddenly occurred to me that my dad used to own both 5 and 3 phase AC welders and I thought "wait a minute, an alternator is 3 phase AC". I searched and searched but I'm doing a lot of searching on a smartphone because of a really long couple of work weeks, plus I suck at Google apparently. (If I wanted to buy one I could find that.) Anyway, I'm just not sure of how a 3 phase AC welder works. Maybe it just turns it into DC. They were just arc welders anyway.

Question by Andale_The_Great   |  last reply


How do I build a converter to run a 3-phase 1/2hp motor from a single-phase residential mains?

I got an old industrial sewing machine cheap. Cheap because it has a 3-phase motor, which made some other hobbyists reject it. The other option at ~150$cdn would be to replace the motor with something more domestic.

Question by berserk   |  last reply



how to find DC capacitor for single phase active power filter?

I am designing single phase active filter, I want formula for Dc capacitor (inverter side) with explanation. Plz........

Question by ssawant4 


How to drive 3 Phase AC motor using Arduino Uno?

I am having 3 phase AC motor in farm. I want to control it using GSM. Please tell me how to do that???

Question by amitsanap   |  last reply


how the crystal connected across the collector and base of a bjt pierce oscillator provide 180degree phase shift?

A normal oscillator will provide 360degree phase shift. of this 180degree is by the transistor amplifier and the remaining 180 is by the feedback circuit or tank circuit. but in the case of a pierce crystal oscillator ,it is the crystal which connected across the collector(output) and base provides 180degree phase shift the crystal provide 180degree phase ?

Question by mishal.abe 



When making wine what does the phase prime it mean?

I new to wine making and dont know all the words yet

Question by michaeltruman83   |  last reply


Does anyone know how to make high internal phase emulsions?

I'm sorry but I can't detail the question any further.

Question by poch   |  last reply



Variable frequency drive

Hello there instructables, I have another question discussing maglev theory and i was directed that the true way to build this project was to use 3-phase power! So this question, although related, is also an entirely new project in its own right! Now to the point, i have been researching single to 3-phase conversion, and there are a few options available like rotary or static phase converters, but i have been intruiged by a device called a variable frequency drive! Okay so what i understand so far (i think) is that these convert ac to dc, run that dc through a H bridge rectifier using igbt's and then convert the 3 outputs back to ac...... okay assuming my analogy is correct so far, to my question, 1. How are the igbt's triggered in the h bridge? do they use a function generator with altering timesteps to create the seperate phases? 2. Also how are these kept in sequence with eachother? Many thanks in advance for any help you can provide!

Topic by Xmortx114145   |  last reply


Can I use 2 push pull pots on the Volume to make the Humbucker "out-of-phase" and Tone "single coil"?

I have a Fender Strat with H-S-S pickups. With Master Volume and Master Tone. Can I use 2 push pull pots on the Volume to make the Humbucker "out-of-phase" and Tone "single coil"?

Question by iMadrid 


3 phase AC motor for electric kart with 12 volt , ten batteries in series?

If it is possible to run motor please give me what motor power i need , how many watt power motor i need ?

Question by Suraj Basnet   |  last reply


Does anyone know how to convert the three phase output from a brushless motor/generator into straight DC voltage?

I would like to pedal the brushless motor/generator to drive a propeller powered by the resulting voltage Thank You?

Question by adamalbert   |  last reply


What are some re-purpose ideas for 4 x 6.5 rmp 3 phase gear motors?

I was given 4 x 6.5rpm 3 phase gear motors from a tug boat. I need some ideas on what i should do to re-purpose them. My first thoughts were some sort of baby carousel or baby rocking machine, they're very quiet and my boss is about to have a baby. The only issue is that I doubt his house has 3 phase distribution so I'm looking to build something useful for around the shop.  Edit: They're 0.5hp motors

Question by NickolisB   |  last reply


Suggestion: populate "what's related" during Instructable Editing phase

It might be useful to populate some sort of "what's related" display while someone is first creating their instructable (perhaps only on demand?) If this means you need to collect categories and keywords earlier, that shouldn't be TOO difficult to do. This would allow the authors to see if they are duplicating an existing instructable, and/or to gather additional details that they might find useful, and/or allow them to explicitly reference other particularly-related instructables... (huh. Is there a general purpose "find me web pages related to the following document" search algorithm? Something better than Google uses to pick ads, I'd hope? Sounds like an interesting research topic...)

Topic by westfw   |  last reply


HOW TO SETUP 5 UNIT OF 3 PHASE WIND TURBINE 2KW 48V TO 10KW 240V HOME

Hai... I need some solution... I'm not a electrical engineering... so, there are 5 unit of 3 phase wind turbine, with rate output up to 2Kw, 48V each... and I need to produce current load for home about 7Kw to 9Kw, 240V,,, so, how to wiring from 5 unit of wind turbine to home current...sorry for my english and thank you...

Topic by zeak1975   |  last reply


Clarifications about a linear induction motor.

Several questions: -Calculate the force of a linear induction motor from the magnetic field/current (aluminum induced surface)? -How does one determine the direction in which is moves considering the magnetic fields are not static and there isn't a second magnet since it is just an aluminum induction surface? -Is there an optimal current frequency for a linear induction motor? -Is there any way to make a single phase Linear induction motor, and avoid using 3 phase current?

Question by amelius   |  last reply