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Sine Generator

I am looking to create sonoluminescence at home and one of the main things that I need is a 25 KHz sign generator!  I have been looking everywhere and I can't find one or how to build one.  I any of you can help please do.  Thanks in advanced Here is a link to what I am going off of

Topic by Cody Heiser    |  last reply

How to upgrade a Modified Sine UPS to Pure Sine? Answered

Hello, How could I upgrade an uninterruptible Power supply that has a Modified Sine Wave to Pure Sine wave? I got a cheap 400 watt HP UPS (for a tenner) with a modified sine wave;  then got to discover it would be much nicer that is was a Pure sine Wave ^^. The purpose is to use it as an inverter for most household items (in a solar set-up). There are videos to increase wattage but I have not found yet something informative enough to upgrade to pure sine. Thank you!

Question by RincewindT    |  last reply

Power Sine Wave Circuit

Hi I am trying to build an economical circuit to power an AC electromagnet. The energy source has to be a battery, preferably less than 24v. The power draw of the electromagnet will be about 500W (the application requires a high-power alternating magnetic flux). I'm thinking of making a sine-wave generator and a simple transistor amplifier with high power transistors. Can anyone suggest circuits for this? My knowledge of electronics is not that great, but I'm quite enthusiastic about this and I believe I can give it a try. Any help will be appreciated. Thanks R

Question by Richy33    |  last reply

How to biuld a sine wave inverter?

I need to build a sine wave inverter but i do not have the schematics.I need an assistance in this project.I can build a square wave inverter but it makes noise in the fan and does not surport my 29 inch television causing it to have frequent low current  problems.I heard that sine wave inverter is more efficient for home appliances.Please can some one help me with a simple diagram to build my own efficient sine wave inverter.Thank you all.

Question    |  last reply

12v to 120v sine inverter boosting

I have a 20 year old van. The a/c leaked and it is much cheaper to buy a 120v window unit ($140 with a 3-year walk-in exchange warranty) than to pay a shop to rebuilt the vehicle a/c. I chose a 5k BTU window unit that uses 4.1 amps running, and have a 1k watt sine wave inverter. Alone, the inverter will not start the a/c unit, but will power the fan. I confirmed a trick to start motors with an inverter. I connected an 8" bench grinder to the inverter and started it. It took a few restarts to get it up to speed. Then I started the a/c and it ran without problems. The bench grinder motor was able to supply the reactive power the a/c compressor needed to start. Both continued to run without straining the van's alternator. BUT, I don't want to travel with a running bench grinder going, that's not safe. Is there another way to supply the reactive boost that is safe to travel with? Once I get a simple stable way to run the a/c I'll work on a mount to vent the hot side. The van has sliding windows.

Topic by DavidN71  

Why is a modified sine wave harmful to electronics? Answered

I was reading an article in a computer magazine about UPS (Uninterruptible power supplies). It said that UPSs produce a modified sine wave. However it said that using a modified sine wave to operate computers over long periods is harmful. I wonder how a modified sine wave could damage a computer. All it is is just a sine wave that steps instead of a perfect curve. Right? 

Question by Super_Nerd    |  last reply

Analog sine wave generator? (0v-5v)?

I am wondering how to create an analog (NOT digital) sine wave from 0 - +5 volts (Not -5 - +5). If you could, post a schematics diagram, or send a link to a page with the schematics. It has to have a variable pitch. Thanks, josh1324

Question by josh1324    |  last reply

Simple comparator problems. (Outputting sine wave)

I just got a couple of LM2903N comparators off of an old board, and decided to do something with them. I have it running on +/- 5V, with the (-) input on 0V, and the voltage on the (+) input varied between +/- 5V on a 100K pot. If it is left like that, a sine wave of about 1.5V and 100Hz is generated when the (+) input is above 0V, and outputs 0V when the input is below 0V. With the output connected to +5V via a 33K resistor, the amplitude of the sine wave is significantly reduced, to about 0.1V Also, as the input voltage passes through 0V, the output will jump to 1.5V above or below 0V, and slowly return to 0V over about a second. The same is seen for both constant output voltage, and for the sine wave. (Tried this with both chips, and both give the same result) Thanks in advance for the help.

Question by The Skinnerz  

turn a square wave froma 555 into a sine wave? Answered

I would like to know how to smooth out a square wave to turn it either into a sine wave or at least a triangle wave. Or if it's not possible i would like to know how to make a sine wave generator to use as a lfo thing for a home made synth. Thanks, Josh1324 PS. It has to be analog, im not getting into microcontrollers or anything digital.

Question by josh1324    |  last reply

Have music control a device with sine wave and frequency? Answered

Whilst I was using  a TENS unit (electric muscle stimulator) and was messing with the frequency and pulse width controls, I thought to myself, "What if I would redesign this device, so that I could plug it into my mp3 player and it control the frequency and pulse width so I could literally feel the music?" After long though, and looking to see if such a device existed (None that I could find.) I came up with nothing. Now my question is, how could I design such a device that would take in standard audio, and give a pulse width and frequency output? I would assume I would use a pulse width modulator (PWM) for the first part, but what about the frequency? And how would I make this as one unit? I am a complete novice at sine waves, frequency, audio, and things in that area, and I find the best way to learn is do a project involving it. So would anyone have an idea how such a device could be designed? Link, circuit diagrams, and tips are all gladly excepted.

Question by RocketPenguin    |  last reply

Do UPS inverters use Modified or Full sine wave?

I've been running my laptop, Desktop computer monitor, and a whole bunch of other things off a cheap 100w modified sine wave inverter for few years now, but have just recently started wondering if I got an old UPS that ran off of 12V for the inverter if it would be cheaper than buying a real full sine wave inverter. But I'm not sure if the inverter is Full sine wave for use with computers.  I have a small off grid system I'm using. Anyone know for sure?      

Question by Bluevitz-RS    |  last reply

I need a circuit that can convert sine waves to square waves.

I need a circuit that can convert sine waves to square waves that works with a wide range of frequencies and doesn't change the frequency, for a project i am working on. I also need a circuit that can convert square waves to ramp waves that also works with a wide range of frequencies and doesn't change the frequency. Thank you in advance.

Question by Super_Nerd    |  last reply

hello anyone here know how to build a true sine wave inverter?

I just wanted to build my own power inverter to get a better understanding of how they work.

Question by first1    |  last reply

Sine wave power inverter ac output fluctuate between 210~230V. Any idea what is going wrong?

Recently build 300w sine wave inverter. First power on without heatsink it fried off push pull mosfet. Replace mosfet and attached heat sink, repower blown fuse and output mosfet shorting. Replace fuse and mosfet, power up again. Resulting with fluctuating output between 210VAC to 230VAC. Check secondary dc voltage also fluctuated. Any idea what was went wrong. Use KA7500 as input driver and egs002 as output driver. Reference - please refer Thanks in advance.

Question by GearUp    |  last reply

What Is The Correct Inductance and Current Of Sendust Power Core Magnetic Coil for 1500W Pure Sine Wave Inverter?

Hi All, Building 1500W pure sine wave inverter using china technology but do not have know-how on the output coil value. I am using EGS002 for output stage. Refrerence: EG8010 SPWM.pdf page 11 figure 8.1a - L is 3.3mH for 300W and EGP1000W.pdf page 7 - I is 6.5A for 1000W. Question 1: The L = 3.3mH is it OK for 1500W pure sine wave inverter? Else simply applied any of this 2.3mH, or 1.6mH or 850uH and etc (found on ebay). Question 2: The peak current (I) = 1.414 * W / Vac = 1.414 * 1500W / 220Vac = 9.64A (10A) calculate with reference to EGP1000W pdf manual. Question 3:  In order to built 1500W pure sine wave inverter, can I use sendust 10A 3.3mH? Please advice. Thanks in advance.

Question by GearUp    |  last reply

can we send analog signal using bluetooth without converting to digital signal?

I wanted to attach bluetooth to lvdt sensor.  output of that lvdt is sine wave . that signal is given to bluetooth , is it possible to send sine wave using bluetooth without converting into digital form?

Question by vijaysinha    |  last reply

Is there any danger in using two different sine-wave inverters (UPS) to provide backup power for my computers?

I'm concerned that having two UPS units in close proximity could be the same as having two out of phase mains supplies and the potential for a rather nasty shock.  Or, are my fears misguided? Thanks.

Question by marto26    |  last reply

Hartley or Colpitts oscillator

I need Hartley oscillator or Colpitts oscillator. I tried a lot but failed. I am simulating circuits on multisim but not been able to get sine wave. Can anybody help me with that?? I am using these oscillators because I want high power oscillator in high frequency range.

Topic by m_uamir72001    |  last reply

DC offset volatage

How do I provide a 5v dc offset volatge to a sine wave? (Using op ams)

Question by wjayashan1997    |  last reply

Will a computer power supply run efficiently on a 12V power inverter? Answered

I am planning to buy a modified sinewave inverter just to power some basic stuffs from a car, but one of my main problem is that i want to power 2 sensitive devices on the inverter. I have a 450W computer powersupply Will it run smoothly or will make hissing noise or will get fried after minutes of use same goes with a 19" inch LCD screen some help here would be  much appreciated thanks

Question by ARJOON    |  last reply

Is there a specific waveform that needs to be produced by the driver electronics in a solid state tesla coil?

Is there a specific waveform (for example sine, square, sawtooth, ramp, etc) that the driver electronics (an oscillator i think?) in a solid state tesla coil in order to properly drive the coil?

Question by UbuntuNinja    |  last reply

I need the circuit details to get a 288hz output from a 12vdc input sine or square wave makes no difference?

I have no electronics  experience and all those I ask say yes you can do but no one has given a method (or offered a made up unit) Please help my brain at 82 is not a spry as it used to be Ian

Question by proffesornobrain    |  last reply

Powering oven resistor Answered

Hey :)Does anyone know how to power an oven resistor ? Is it really a simple resistor (I'm not sure as it is directly exposed in oven, it seems too dangerous for the user if it is simply a metal stick) ? If I plug it to 220V sine 50Hz will it heat ? Thanks :)

Question by QuentinP16    |  last reply

Need help for Oscilloscope-like device

Hey, Im a noob to instructibles, but was wondering if anyone could tell me how I could get a TV or CRT, LCD, or OLED, to display a Sine wave, I want it to look like an oscilloscope but I dO NOT need a functioning scope, just want a display with the cool graphic for prop/filming purposes. It would be really helpful if it could just be a circuit which outputs an NTSC signal that is a sine wave, thanks in advance inventors of the world! Ultimately I would like to have a scope-like display that responds in appearance like a VU meter where you can see the sound as a voice waveform based on volume/pitch etc.

Topic by Aleator777    |  last reply

Gas furnace plugged into 120V solar/wind generated power bypasses the thermostat control and starts immediately. Why?

The sine wave generated by my 12v to 120v inverter scopes even better than the grid current.  All other appliances function normally on off-grid power.

Question by Twicewidowed    |  last reply

Is there a cheap creation to make a 110v 9-45 mA power system?

I am looking at three ways for this right now. My preferred long game is a solar cell block (minor one, i am not sure of the power output calculator cells have, but along that size I am guessing) that feeds into a digital sine wave form for my output ( low end of power is fine.) I need the sine wave chips to do the build on a +/-110 V wave then, but the ampere I need is ultra tiny by current standards. The total power of this concept is about 1 watt. Perhaps a amp limiter off a wall circuit second as my second but probably easier choice. Reading up on some interesting theories, but to test them accurately, I need this base component(s). I will post the results of what I do with the device pas or fail, as I think it will be important to some of the current over unity power system theories bouncing around to have good well documented answers.

Question by JBrenton    |  last reply

Questions about AC motors and removing printing from canvas tote bags

I found ahem dived for a motor a few weeks ago that runs on ac. Could I use 2 relays and a 555 to get 60hz AC with a square wave or does it have to be a sine wave to run properly?Second question:How do you erase fabric paint or screen printing from a canvas tote bag?Thanks

Topic by LinuxH4x0r    |  last reply

Can I make an uninterruptible power supply for my furnace?

So, last winter, my area got TONS of snow, very cold temperatures ( I spent 20 minutes dropping droplets of water on an iron railing and literally watching it freeze), and then we lost power. Our furnace runs on natural gas, so it would've worked, except that the fan inside it and also the ignition system (I'm pretty sure) wouldn't work without power. I'm thinking of getting maybe 10 or so surplus marine/car 12 volt batteries and a high-power inverter, and running the furnace off normal 120 AC, until power goes out, then a relay ( or some solid-state circuitry) would trigger the batteries ( in parallel), which would charge either off of a solar panel outside, or wall power once the power was back on. Also, the furnace has what looks to be a pretty basic motherboard inside of it, would I need an inverter that makes a really sine-y sine wave for that, or could I get away with a cheap square wave one? Also, it's wired directly into its own circuit, though I'm pretty sure it's still 120 V. Comments, advice, etc. is welcome. Thanks!

Question by mad magoo    |  last reply

Export integer from arduino to processing?

How can I take an integer or float value from an arduino, and put it into processing over serial (usb), without changing it to a char or something else?  It needs to be fairly fast (within ~1/8 sec), and be able to be converted to an audio tone.  Also, how can I play an audio tone in processing?  I looked on the reference page, and couldn't find any documentation on just a basic square or sine wave output of variable frequency (except the example, which uses something weird). 

Question by jduffy54    |  last reply

Best way to accurately measure capacitance w/ osciloscope?

I am sure there are many ways to measure capacitance w/ an oscilloscope, and one of the annoying things is that some capacitors have different capacitance at different voltages and test frequencies. My original idea was to use the RC time constant and a known resistor, but I think this is probably the least accurate way to do this. Would using a sine wave function generator and figuring out capacitive reactance (and capacitance) be the better method? OR what about measuring resonant frequency of a LC tank circuit? Or some other method I have not mentioned? What's the best?

Question by -max-    |  last reply

Waveform Generator

Hi guys! So actually i wanted to make a circuit that can turn on and off an LED array at a particular rate (say 10 seconds time period). I want the LEDs to gradually brighten and dim. At first i thought i can implement it using a multi vibrator, but it it turning off and on too fast, since the output of the MV is a square wave. I want to design a simple circuit that can generate more slowly rising waveform (like sine or triangular) and can also drive a load of at least 100 mA and have a time period of 10 seconds or so. Any suggestions? 

Topic by charmquark    |  last reply

Wire bending jigs, does anybody remember some???

I need to make some springs for a recliner. They are the ones that support your back. They look like a sine wave. I have 1/8 inch piano wire, however it is really tough to get bent into the correct shape without a jig. Does anyone out there remember seeing a bending jig on Instructables that had various diameters of bends, etc? The only one I can find is associated with making a NAROD antenna. The piano wire is a lot tougher than the copper used for the antenna. Thanks for any help...

Question by bucklipe    |  last reply

Is it possible to use the guts from a flash disposable camera as a high voltage square wave generator? Answered

Is it possible to use the guts from a flash disposable camera as a high voltage square wave generator? I know that in order for the transformer to work it must use AC voltage so the 1.5 DC is changed to some high voltage AC but I'm not sure if it is square wave or just regular sine wave. And I'm also not sure at what point the AC is changed back to DC for storage, any help? A schematic or some diagram would be much appreciated!

Question by arhodes18    |  last reply

Why use 2 mosfets? Answered

Http:// In the circuit, they use 2 mosfets namely q1 and q2. I was thinking what does q1 do. I tried simulating the circuit with and without q1 and the result were identical. Almost all synchronous rectifiers are following this pattern, what could be the purpose of q1? input and output conditions... Input: sine wave similar to AC mains (100Vrms 60Hz) Output: half wave rectified sinewave Load: 1kOhm resistor The red curve in the graph represents the voltage in the output The blue curve in the graph represents the voltage of a 1 ohm resistor in the input (for current reading purposes)

Question by codestroy7    |  last reply

How to Identify or Measure Inductance?

I am gathering the parts for an ible, but I am short one part: a 12mH inductor.I can spot some inductors in electronic garbage - the wire coiled around a ferrite loop - but there are also solid state inductors. Plus, the inductors are not usually labelled with their values.How can I measure the inductance of an inductor with a volt-meter and an ammeter, but without access to a sine-wave generator?Is there some simple trick that would get me "close enough" to the true value? What would be really useful (but probably doesn't exist) is a chart or formula where you plug in the size of the core and the number of turns around it and out pops the inductance value. ?

Topic by Kiteman    |  last reply

Input problem with OpAmp-controlled ZVS Induction Heater

Hello, Idea: I'm trying to build a circuit which uses an OpAmp to drive 2 mosfets, which power the LC tank of an induction heater. The idea is to detect when the voltage over the LC tank crosses zero, and at that voltage I would make the 2 outputs of the OpAmp change states from fully on, to fully off. The two OpAmps (both inside one chip) have their positive and negative inputs connected to eachother, but with reversed polarity. This would make sure that one output is high, and the other one is low. Why use an OpAmp? I wanted the MOSFET gate switching to go faster as usually, because in the mazzilli circuit, the gate voltage actually slews at the same rate as the LC tank's voltage slews when it crosses zero volts. In the mazzilli circuit, it actually doesn't switch when the voltage is 0v, but when the tank voltage drops below the gate threshold voltage. This would mean that you are always switching current at 5v (for example) instead of at 0V. So for these two reasons, I wanted to try switching them with an OpAmp. Measurements: Probe I on drain 1, probe II on drain 2, and GND on the circuit's ground, gives me an expected result: when switching states, at 0 voltage of the LC tank, the voltage on one side stays low (since it's pulled to ground) and the voltage on the other side goes from 0v up to 50v, back down to 0v, like a sine-wave. Then the OpAmps switch again, and the one side now goes up to 50v as a sine wave, and the other one stays low at 0v. All good, this is working just fine. Probe I on the one differential input line, probe II on the other differential input line. Since this is nothing more than just a 1/10 voltage division of the previous measurement, I'm also expecting the signal to be exactly the same, but 11x smaller. -> problem: However, this does not happen. Because of some strange reason, as you can see in the scope images: Both channels go high, Twice per cycle, instead of going high only once per cycle, and staying low for the next half of the cycle. This really isn't good! Do the inputs affect the waveform in some way? Remarks about scope images: Image: 2 gates Blue gate voltage seems 'quite' fine. Turning on looks good, turning off is not really good becuse if tends to turn on for a short time once again, before it fully turns off. Yellow gate voltage is terrible. Turning on doesn't happen as expected. Voltage drops back to 0 for a long while which is very bad for the circuit. Frequency seems fine; 50kHz is as expected with the 14µH and 6µF. Image: 2 drain voltages These voltages were measured with a 1-10 voltage divider, and thus show only 1/11th of the actual voltage. This is getting close to what I want the LC tank to do. The voltages seem quite like sine waves. I suspect that if the gate voltages would be as they should be, these drain voltages would also be perfect sine waves. The regular sine amplitude of 50V is as expected, with a 24V supply voltage, but at the moments when the drain voltages strangely drop down to 0v, as you can see in image: '2 gates', at these moments the drain voltage seems to spike over 250V!! Image: 2 differential input lines This is the image which I don't understand. I expect the same wave as in the previous picture, but only 11 times smaller because of the voltage divider. However, the voltage does NOT reach 0v while the drain voltage does, and its shape is also completely different. In this image, both channels are doing one (half) sine wave, twice per switching period. They should be LOW for half a period, as the drain voltages do in the previous image. Better quality images: 2 gates 2 drain voltages 2 differential input lines schematic Datasheets: OpAmp: MOSFETS: Coils and capacitors: Line inductor value: I'm not sure if this value is correct. Center-tapped main coil inductance: This value should be pretty correct, I calculated it by measuring it's size and windings, and the operating frequency is also nearly the same as the calculated one. tank capacitance: 6 times a 1µf MKP capacitor Questions: - Why these strange large spikes? - Why is the waveform suddenly different when reading it near the differential inputs? For the first time ever, I can provide you with scope images! I finally bought a (quite cheap) oscilloscope. I hope it helps a lot. Oh, and one more thing: The induction heater does actually work already. I'm getting huge currents in the LC tank, since the 6mm copper tubing gets hot after a minute. Water cooling has been added, and it works like a charm! The MOSFETS do get quite hot after 15 seconds of heating an object, or after 40 seconds of heating nothing. This, probably because the gate voltage isn't what it should be. Kind regards, Electorials

Question by DELETED_Electorials    |  last reply

Trying to convert a mains powered string of LED's

Hi, I purchased a set of Xmas lights believing them to be 'low voltage'.  My plan was to run them from the caravan 12 volt DC.  However, it appears that they run from the 230 volt AC mains.  This is something I am not familiar with. I have attached my own wiring diagram of the circuit and would like to know if anyone can tell me how to switch the four strings of LED's individually.  I have an inverter that I can use as the current draw will be minimal. I imaging that the LED's are wired as opposing pairs so that both halves of the mains sine wave are used.  Presumably, this prevents the set being run from 12 volts. Any help will be welcomed. Alan ...

Question by newalfi    |  last reply

Can I generate electricity from a Sterling motor?

I'm trying to figure out a way to recharge a 12v 100kwh lithium ion battery - used for my husband's CPAP machine.  Solar panels are available, but not always reliable and they take a couple of days to recharge the battery so now I'm looking into building a sterling engine to recharge the battery.  I also happen to have a 150w sine wave inverter, but I'm such a newbie I have no idea if this would be helpful in moving power from a motor into a battery.  The inverter does connect to the battery though.  Anyway, can anybody out there help me figure out a way to build a motor to recharge this battery.  If it's not possible to recharge this particular type of battery I may go to ways to charge up a 12 volt marine battery

Question by ChristiD4    |  last reply


Recycle, how do YOU help the environment by recycling, do you just toss plastic and paper products into correct bins whit the recycling sine in it or do you reuse old stuff, remake to keep up whit the time, take action yourself. What do you do? For example, I recycle old news paper... Its a whole proses, first you cut the news papers into smaller peaces, then you let it set in a special, secret concoction, then you blend them, then a secret method of removing the ink from the paper, and finally evenly distribute the sludge into a mold and let it set, dry. One day I might make an Instructables on how to recycle old newspapers. So what are your actions on helping the Earth recover?

Topic by comodore    |  last reply

Vibration comparison

I'm trying to compare two wildly different measurements, but I don't know enough about the physics of sound to even know what information I'm missing. I don't need exact numbers: some upper and lower limits would be fine, and perhaps even "back of the envelope" calculations in case the required information can't be found. I'd appreciate some advice on the formulas I need and what measurements am I still missing.  Object A is producing a sound whose intensity measures 25 dB at a distance of 1 meter.  This sound is, roughly speaking, a band-limited sawtooth wave with a fundamental frequency of about 35 Hz.  Object B is being driven up and down a distance of about 0.5 mm with an acceleration of 0.3 times that of gravity. The sound doing this is a sine wave with a frequency of 35 Hz. I'd like to compare the peak accelerations experienced by the two objects.

Question by CuriouserAndCuriousest    |  last reply

Audible frequency amplitude modulation of 20kHz carrier for diffraction demo. Answered

I am attempting to build an audio projector that takes advantage of the low diffraction of high frequency audio waves. Audible range frequencies diffract more than, say 20kHz, so I want to modulate a 20kHz carrier wave by an audible range source, hoping that the carrier wave will be maintained for longer distances (like a beam of sound), and that my ear will ultimately perceive the audible input being delivered on the carrier wave. My question is: Should I be aiming to produce an AM Radio type modulation that has an envelope of the input both above and below, mirrored across the x axis? Or should I try to make it so the final signal has the same shape as the source wave, just filled in with 20kHz carrier? Also, is a square wave carrier sufficient, or will it need to be a sine wave?

Question by laserjocky    |  last reply

Which of this is the right Thermistor for this switching power driver board?

Hi Instructables Members' Schematic link;=STRK%3AMEBIDX%3AIT please see the schematic on the most right. Which of this is the right Thermistor for this schematic: a) For 50S can I use this      1) or      2) ; and b) For NTC/10K can I use this      1) or      2) Thank you in advance.

Question by GearUp  

Wind Power Charge Regulators

Hello!! I need some help here...I am very "green" when it comes to alternative energy, so bear with me please! I recently decided to put together a small wind generation system to power my workshop. System is comprised of a 38v Ametek PMDC motor, 6.8' tri-blade array for propulsion. I also intend on installing a 2000 to 3000 watt modfied sine wave inverter powered by my battery bank to provide AC voltage to the shop. I want to be able to used the majority of the power created by my wind generator. I understand the concept of using a "shunt" but do not have a need for hot water or useless lighting. My question is this, would the Flexcharge NC25A charge controller ( be sufficient enough to used in this system? Or is there something else out there that would maintain my battery bank without shunting the load when the bank is fully charged....Thanks in advance.

Topic by NMCBDet23    |  last reply

Any ideas on how I can hoop up an old synth to a PC?

I have this pretty old synth that has no midi out, just out for a speaker. About the hookup, I know I can just hook it up to my PC's Microphone/Audio Input and record but that's not the point. What I want to do is hook it up to a program (like Reaper) and use the program's synths. So, just use it as a keyboard. And from what I can('t) tell the output is something like square wave (also it can put out sine on the bass keys and i think some options have triangle waves.) Also I have no idea what model this thing is, all I know that it was made by Vermona and it makes a pretty good sound. It's completely analog. Thanks in advance

Question by T0C    |  last reply

Variable DC input to a clean AC out put

So here is what I am trying to accomplish. I am trying to take an old Jacobs wind turbine controller that was designed for a grid tie application and make it off grid. There is a 3 phase "wild" ac input from the turbine that is rectifyed but not clipped by the internal SCR's to variable DC (40-180 volts). The sensing was designed to tie to the grid and power sync'd to line power and freq then exported or imported depending on demand. What I would like to do is build a Variable Dc input inverter that will put out a pure sine wave 120/240 vac split phase. Thus imprinting a usable power out put and allowing the cap/choke inverter to do its part. The design need not handle much power as it is only used as an imprint to regulate the power through the controller. If anyone had any idea on a build for this or a manufacturer that is producing such an item I could really use some ideas. Thanks

Topic by nbrooks  

Does ClassD amplifier not suitable for 60Hz transformer?

Hi there, My application is in Audio range. I am going to use a Transformer instead of Speaker. A 3- phase power calibration is my intention. Similar to this link, My current AMP design might be class AB type. I am thinking how can I move class AB to Class D amplification. A lot of the design effort relates to maintaining linearity and avoiding crossover distortion. 2 amplifiers( current, voltage) output will feed to CT and PT! REQUIRMENTS : 1. The amp input should be plus and minus 7volt AC, 45-65Hz( 1 Hz has been converted to 1024) 2. Amp operating voltage should be more or less 24v. 3. 2 channel signal (not sure PWM) should be use , one for current, one for voltage. 4. Can run current transformer(input 16.5 V/1.5 A) and potential Transformer (input15v/2A). 5. If possible both voltage and current amplification is required in one IC. 6. Both positive and negative half signal should be amplify. For CT, current transformer primary winding has 80turns, 16.5 V/1.5 A, secondary has 20Turns, 4.125v/6A output!For PT, Potential transformer, Primary has 80turns, 15v/2A rating input, secondary has centertap! At secondary 960turns, 360v/0.332 A and 960turns 180v/0.166A output.For the time being lets disscuss issues like, 1. Low frequency and high frequency phase shifts caused by a transformer will occur if the transformer is inside the negative feedback loop (when the output of the transformer provides the negative feedback). Then the amplifier must be compensated for these phase shifts.A transformer causes a phase shift at low frequencies caused by its inductance. 2. A product with a Class-D audio power amplifier (APA) driving an output transformer with inadequate low-frequency performance may shut down when its output is stepped from zero to maximum at the start of a sine cycle. Shutdown is triggered by short circuit protection (SCP), after the first half cycle of the sine output. The root cause is saturation of the transformer core. 3. Class D amplifiers approximate voltage sources, they won't take kindly into a CT load.

Question by Hasan2015  

Can anyone explain RMS vs average? (particularly the math portion, and the intuition)? Answered

My current understanding of RMS (Root Mean Square) is that it is the equivalent AC voltage/current/power necessary to drive a resistive load the same around as the DC voltage/current/power counterpart. However, I am a bit confused about the math involved that can apply to all waveform. I know the conversation factor for sine waves is 1/ sqrt(2), and that the conversion factor for square waves is 1:1 (no difference) On my graphing calculator, if I take the square root of the definite integral (from 0 to pi, integrating the x ) of the sin(x)^2, then divide that by the period, pi, I get the correct answer. However, what is the purpose of the squaring, then square-rooting? is it purely to perform a absolute value mathematically? If so, then I should be able to simply integrate the absolute value of the sine, and divide the result the the period the integration was performed over. If it period it was performed over was 0-pi, then there is no need to even take the absolute value! But this method returnees 0.636619... not 0.707106... Intuitively, it makes much more sense to me to somehow take the mean average of the continues |sin(x)| function. I know this can be done with desecrate numbers (a sequence, perhaps) and by taking the sum of them, and dividing it by the number of 'elements.' (series's, anyone?). I would expect this average is what determined the average power used by a load. EDIT: Wikipedia states that "The true RMS value is actually proportional to the square-root of the average of the square of the curve, and not to the average of the absolute value of the curve." So it appears I have just proven this. But Why???? What is so special about the squaring and rooting??? Please don't bombard me with heavy math, as I am not familiar with calculus, and have barely passed pre-calculus (The class was supposed to touch upon series and sequences, and integrals, derivatives, limits, etc. but due to show days and delays, the class only covered trigonometry --the bare essentials--). I do not yet fully understand single-variable integrals, let alone multi-variable calculus. I really just want a better intuition of RMS. More than likely, there is probably some confusion I have about integrals in general, and how to calculate them on-paper.

Question by -max-    |  last reply

Half-Wave Rectifier Question?

Hello Everyone, Well, I built a half-wave rectifier using a diode and a resistor, but it doesn't seem to be working as I want. I'm thinking of adding a capacitor to help smooth out the wave, but my whole purpose was to produce a pulse of energy at 60Hz. Basically, to just chop off the lower half of the sine wave. For my diode I used a 1N5406 rated at 600V and 3 amps. The resistors are rated at 20 watts and the whole thing just plugs into the electric outlet. It seems to work ok, but when I take this rectified output and put it into a transformer to step it up to around 1000V thats when I have a problem. After its stepped up its supposed to charge a small capacitor from which the electricity (when built up) will jump across a small spark gap. The spark gap is adjusted correctly, but he capacitor doesn't seem to like to charge on this wave. Its rated 2KV so voltage isn't the problem. The problem is that it will fire once, but not repeat the cycle.  (The transformer shouldn't be the problem because I'm pulsing the dc) Any Ideas? Thanks

Question by transistorguy    |  last reply