I've never designed a filter before and I'm not sure if you can do this. Basically I need a way of filtering out all signal except for signal in the range of 40-150 Hz
Topic by guyfrom7up | last reply
Hello, I am currently building a large set of speakers, and have just discovered the annoying "frequency dividers". Is there any good guide on how to make one at home, as everything that is sold online is too expensive for me. As a 13-year-old, earning $20.00 can be tough. (Don't say I'm lazy, I'm not. I literally get $20 every $%@!# time I complete a hard piano piece. So far, I haven't completed one "hard piece". It's... been... 4 MONTHS!)
Question by Cheesey125 | last reply
I have an Arduino Duemilanove and was wanting to know how and/or what I need to do to create a high frequency signal. I dont have a set frequency in mind but would rather know how to change it so I can gradually step it up until I get desired results.....Have looked at a lot of stuff on google for how to do this and most refer to a wiring.c file but mine appears to be an updated version to what they have...Anyways any help would be greatly appreciated =)?
Question by afreeland | last reply
For a future project (blue barrel infra sub woofer with ducted fan) I'm already looking for parts. I see most amplifiers and amp chips (like the TDA7294) have a frequency response usually 20 - 20,000 Hz. But I'm interested in a range from 0- ca 40 Hz. As far as I understand, the low cutoff is to protect the driver (speaker). Would it be possible to circumvent the low cutoff, or would I have to build from scratch? (I'm thinking in a 70 - 150 W RMS range).
Question by BobS | last reply
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
Look at a picture of some arcs from a common spark-gap Tesla Coil, and then compare it to the arcs from a solid-state. What makes the two so different? The difference comes from the Solid-State Tesla Coil to operate in CW (constant wave) mode. This means that its power supply is uninterrupted, whereas in a spark-gap type, power is being switched on and off hundreds of times per second. If the output terminal of a CW coil doesn't have a brake out point, no corona or spark will occur. For anyone who's investigating wireless power transmission or Tesla's version of radio, this is a very helpful feature, since corona only wastes energy. And if it does have a brake out point, it can create some pretty interesting spark displays, as I mentioned above. An arc to a grounded object increases the current in the arc to such a point that it turns into a white-hot "flaming" discharge. All-in-all, a CW type coil is a pretty interesting kind to observe. But solid-states can be pretty difficult and annoying to build, and expensive as well. Since solid-state technology obviously was not available to Tesla, he found a different way to operate his coils in CW mode- a generator that was specially designed to produce radio-frequency power. He had originally created it for high-frequency arc lighting. Today, I have seen absolutely no coils run by a high frequency alternator. Of course, an alternator would be admittedly difficult to build, but since it could probably deliver more power than a solid-state coil, it would be worth it. Does anyone know if there are any companies that still make these alternators? Would anyone be interested in recreating it? Should we even bother? Thank you for listening. Peace!
Topic by ElectricUmbrella | last reply
My multimeter can measure up to 20MHz and I was wondering if I could test the resonant frequency of my Tesla coil by running it (untuned) then having the multimeter attached to an inductor a few feet away? Would this work or would I need some kind of small circuit attached to the multimeter as well? If I could do this would it work with the primary as well?
Question by The MadScientist | last reply
Hello everyone.. I would try using a 12v transformer halogen (please see photo) for flyback driver (about 10-30 watts) .But seller sell on Ebay do not know the frequency of 12 vac, so could you help me to know that(frequency of 12 vac out) thank you in advance.
Question by lam | last reply
i want to measure the frequency of this flasher circuit but i always get a frequency close to that of the mains. I am using a wall wart. i changed some of the components to speed up the flashing but the frequency reading stayed the same. to check my multimeter i tried measuring the frequency of mains and the joule thief circuit and it looks like my multimeter is good. how should i measure the frequency in this flasher circuit?
Question by codestroy7 | last reply
I try to configure a tv / video card on my computer to display input from composite video (yellow plug) input when i choose any of the inputs i still have to set the frequency (above). it should be some fixed standard frequency. what is it for pal b/g ?
Topic by 11010010110 | last reply
Hello, I've been breaking my head on this for a while now, and still couldn't find a correct solution for this. I want to be able to adjust the duty cycle (pulse width) with one potentiometer, and the frequency with another potentiometer, using a 555 timer. Adjusting the frequency shouldn't change the duty cycle! (which is the problem in All of the circuits I find online). This is an example of a circuit I find online, many of the circuits look just like this one (see picture) Now, the problem is that when you increase the resistance of the potentiometer for adjusting the frequency, that makes sure you can never get 0% or 100% duty cycle anymore! or not even close to that. It's because increasing that resistance, also decreases the 'discharging current' of the capacitor, so it will also increase the discharging time when that's not wanted. Without R2 it works perfectly, from 0% to 100% duty-cycle; but with the frequency potentiometer it all gets messed up. It's a little difficult to explain, I'll try it with another example :) To get 0% duty-cycle (or something close to that, like 10%), you'll need to make sure the path for Discharging the capacitor goes near 0Ohm. Increasing the potentiometer for the frequency makes that impossible because it's in series with the capacitor's charging and discharging circuit. So that would also increase the discharging time while I don't want that. When the resistance of the frequency potentiometer increases, the duty-cycle gets variable between just something like 45% and 55% (example) so that's not good. Is there any way do do this? :/ Thanks in advance, Elecotrials
Question by DELETED_Electorials | last reply
I am trying to modify an old am fm radio, so that it can pick up transmissions from a walkie talkie. I know the frequency at which the walkie talkie operates, but I can not tell the frequency of the radio when I am adjusting it. Is there any computer program, or something that can tell me what frequency I have?
Topic by Sedgewick17
I want to make a spectrum analyser and I want to use a micro controller, but I don't know how. I want to know if the arduino (any one) can split up the different frequencies and output them, so I can use it as an input to an LED driver (LM3915). This will allow the LEDs to be at full brightness and respond to the output of the arduino, if the frequency filter is possible. If not, I will use a series of bandpass filters instead. I want to make an 8 band spectrum analyser. I just thought that using an arduino would be cheaper. Thanks. The schematic I will be using: http://stavebnice.postreh.com/picture/PT041_schem_v.gif
Question by knektek | last reply
Hello i am working on a go kart but instead it will be powered by a 1/3 horsepower split phase AC motor. it operates off 768 watts and i am curious in using a Microcontroller and a high power H bridge to control it. can anyone help me or give me an idea on how to step up 12v dc into 120v dc and then using the H bridge to generate the frequency and also where to find some NPN transistors that can handle it and how to possibly reverse the direction of the motor?
Question by luig | last reply
How To Create Frequency Specific Microcurrent? I am looking to build a two channel (A/B) microcurrent (allowing from 20 - 600 microamps) with selectable frequencies ranging from 3 to 970 Hz). This is based on a medical device that I'm looking to replicate. I've figured out some of this but again, considering the wealth of knowledge here I'm sure some would know the best way to build this. here are specifications Description Device Specs Frequency Range: 0.1 – 999.9 Hz programmable Wave Form: Square pulses Duty Cycle: 50% Current Intensity: 20μA to 400μA Constant current generator Output Polarity: Programmable alternating, positive or negative Output Load Resistance 0 to 100K ohm Output Channels: Two fully independent channels Output Connection: 3.5 mm mono phone jacks Programming Port: micro-USB Memory: Professional-up to 999 programmable protocols; Patient: up to 99 programmable protocols Power Supply: (2) AA alkaline batteries Dimensions: 5.1 x 3.2 x 1.2 inches Weight: 6.42 oz here is the link i am following https://mendtechnology.com/product/mend-professional-package/
Question by kedarg2 | last reply
This is a 3 part question: 1. I am a bit confused. Radio frequency covers 3KHz to 300GHz, so it basically includes bluetooth(2.4 GHz). Why is it that some people talk about bluetooth as something not relating to RF. Do they have different transmission methods? WIFI is also @ 2.4GHZ. What is the distinction between WIFI and bluetooth that makes them so different, covering different ranges, and being able to send different amounts of data at different speeds. I always thought it was the frequency of the wave but WIFI and bluetooth are the same yet they are so different. 2. I am building a project. I need to send data wirelessly. The data is very simple just to turn on or off a series of leds. A friend of mine told me to use radio waves. What does he mean by that exactly since radio range is huge. Is he talking about 40MHz like the RC cars? 3.Bluetooth or RF(again im assuming this to be the same one as RC cars since i will break apart an RC car to remove the transmitter/receiver)Which method consumes less power to send the same amount of data. Distance will not be over 10 meters so i'm not worried about that. Thanks for the help everyone, much appreciated! Chris
Question by Chris414 | last reply
Hello, Does anyone have an instructable for building a proximity detector based on a radio transmitter and receiver? Or some other wave based method? I've viewed the IR proximity detector here on this site, but I need a transmitter/receiver based one. Yes, this is for my pet. I have 2 cats and 1 dog. I need to keep the dog out of the same areas that the cats are allowed to go into, thus the proximity detector needs to be specifically tuned to the dog. Distance does not have to be far, anywhere from several inches to a couple feet. Appreciate any comments or instructables! Thanks, Eric
Topic by riccarr | last reply
Alright so I am doing this project and we have to find out the fundamental frequency of any input signal so that we can use that information to select sampling frequency. Can anyone point me in the right direction regarding making a circuit which can measure high frequencies in the order of GHz even?Thanks!
Question by Hussam | last reply
Question by thanec | last reply
Hello all fellow makers ! It seems I can change the frequency of almost any other email sent from Instructables but I can't figure a way to reduce the frequency of the newsletter. Once a week would be nice. Is there a way ? Thanks, Guillaume
Topic by aka.guf | last reply
I have some battery operated chase lights (Christmas lights) that I want to wrap around a musical instrument.. When I play a note, I want the frequency of the note to drive the chase light speed. So higher notes will make them chase faster than lower notes.. How can I do this?
Topic by 3DPiper | last reply
So This question has two parts.... i need to measure the frequency of a computer processor.....and an avr microcontroller........ actually i want to know weather it is possible to connect a arduino to a pc's processor through wires or an avr through wires to a secondary system like an arduino which will measure the frequency....... and is it possible to overclock an avr ? if yes , then how can i ?
Question by _Boltz_ | last reply
First off, I know next to nothing about acoustics or sound science of any kind. My idea is to make some sort of passive amplifier, like a horn, that is optimized for a single frequency, I'm thinking about 4KHz. I have no clue how to go about designing such a thing and all the info I found on google was too complicated for me to understand. Does anyone has any starting points for me or just general advice/suggestions? Or, if you're feeling generous and/or really bored, would anyone like to design such a thing for me? Thanks ~Josh
Topic by Josh_Blackburn
I am given to understand that the length of an antenna is proportional to the wavelength of the signal that is fed to it (a quarter wavelength, for example). In the case of a signal modulated by amplitude, the frequency (and therefore wavelength) of the carrier wave remains unchanged. However, in the case of a signal modulated by frequency, the signal fed to the antenna will vary in frequency (and, therefore, wavelength). My query is this : how would one go about calculating the length of an antenna for a frequency modulated signal? Its frequency is not constant, so to construct an antenna of say, a quarter of the wavelength, would be impossible. I thank you in advance for your assistance. AlexHalford
Question by alexhalford | last reply
Dear all.. Please help me to know : what is difference frequency meter and counter between 2 devices (please see photo) Thank you so much.
Question by lam | last reply
I want to experiment with inductive coupling, I have made two similar pancake coils of 16 turns of 12 AWG wire(I had it around ) . Now I need to generate a frequency, I know I can generate one with an arduino but I want to generate one to work with the 12v input from a computer PSU to make it more practical. Any way to do this? I'm kinda new to coils/frequencies.
Question by Tom101222 | last reply
Dear all... At this circuit please help me to know: - How many cycle (frequency)and duty cycle : time high and low (percent) for better driver this circuit. Sorry for more question.If I change other transformer (ferrite core)and driver by 555 timer, frequency and duty cycle must be modifier or not ? Thank you in advance
Question by lam | last reply
Hi Everyone I wanna to know where can i get frequency converter transformer that it's input is 2 wire (220v-50hz) and it's output is 3 wire where the voltage between any wire and com. is 110v and between the two wires is 220v
Question by MohamedE7 | last reply
I have an old gaming steer which is not compatible with win 7+, and I can’t find its drivers either. So, im manipulating it on my own, and will use 4 IC NE555 and a potentiometer in astable mode to press [w/s/a/d] with I-don’t-know-what range of frequency. Is there anyone could suggest me use what range of frequency? I thought 700–4000 Hz would be ok. But I have no idea if it is, or not
Topic by Nimasa77 | last reply
Hi , i just got this Rc Nikko Heavy metal, i think it's quite rare because i can't manage to find it anywhere in the Internet. So, it was an old lady who gave it to me on a garage sale, and it came with a rechargeable 7.2 v battery pack, but the controller was missing, and i don't know how much MHz it's on. so how can i change the frequency, does it work with a donor car?like i change the whole electronics setup? 1000 thanks for answering
Question by CeskoG2311 | last reply
Curious if some of the electronic gurus might have the answer to this. I am looking to build a two channel (A/B) microcurrent (allowing from 20 - 600 microamps) with selectable frequencies ranging from 3 to 970 Hz). This is based on a medical device that I'm looking to replicate. I've figured out some of this but again, considering the wealth of knowledge here I'm sure some would know the best way to build this. Oh yeah, I figure using a rechargeable battery which could be whatever voltage is best recommended. So what do you think???
Question by pletchman | last reply
The goal: cheap, easy(ish) electricity. The power source: concentrated sunlight or fire. The question: Has anyone here made them self one of these? : a thermoacoustic electric generator which runs at high frequency. I'm not talking about a sterling engine at least not exactly. Rather I'm looking to make something that resonates much faster and could be harnessed with a voicecoil or a piezo electric transducer. This has been done by grad students and researchers but I haven't seen any built by the DIY crowd. There are some startups around who tout this method because it is more efficient than a sterling engine and easier to build because there are essentially no moving parts or sliding seals. The higher frequency seems to be the tipping point in efficiency because there is less gas moving but moving with the same energy: "Minimizing the flow velocity of the gas overcomes viscous losses inside the regenerator, whose tiny pores allow heat to move between gas and solid most efficiently." http://www.americanscientist.org/issues/feature/the-power-of-sound/5 I'm thinking of making something with common materials: a loop of steel pipe and speakers or a bunch of piezo buzzers and a bike tire valve to add compressed air (for higher frequency oscillation). Can anyone lend the voice of experience for us? Here's some reference material: http://www.wired.com/science/discoveries/news/2003/01/57063 http://en.wikipedia.org/wiki/Thermoacoustic_hot_air_engine In greater depth: http://www.americanscientist.org/issues/feature/the-power-of-sound/ http://www.aster-thermoacoustics.com/?page_id=141 Videos: http://science.discovery.com/videos/invention-nation-thermal-acoustics.html http://www.youtube.com/watch?v=Vv0ulNLRkWM And there's a good explanatory video out of Europe but I can't find it now. Key words for 'bots: TAPEC ECN TAP (Thermo Acoustic power) SCORE (Stove for Cooking, Refrigeration and Electricity)
Question by snotty | last reply
Is there an easy way to change the electrical frequency? From 45hz to 60hz?
Question | last reply
I currently have bought an aquarium pump from the UK and am using it in the United States. I have bought a step up transformer that goes from 110v input to 220v output. The pump works, but is not functioning properly, it loses flow rate over time and gets pretty warm. One thing that I think may be affecting the performance is that the frequency difference between what the pump is rated at and what is supplied here in the US. What would be a cheap (<$100) easy way to test if it is the frequency issue? How would I convert it? Thanks!
Topic by brandon3rdstone | last reply
How do i use 433M-Transceiver-Module-E32-TTL-1W-SX1278-SX1276-30dBm-LoRa-Long-Range-433MHz with arduino uno, like schematics, codes, what is MO, M1 to transfer data as I can not find much about it. Cheers
Topic by laidlow7
Hello every one, Since i am totally new to PCB designing and all these stuff, I want to know few things about Eagle CAD tools I will be designing a Frequency up-donwn converter as a University course project. out of many components selected for this project one of them is as follow. http://www.hittite.com/content/documents/data_sheet/hmc523lc4.pdf i have gone through designing of the LC4 package, i hope it would be fine, still i would like to know how to creat ground of a package, creating outline boundries of package (is it from wire or from rectangle, polygon??) and about symbols inside this package, i am confused about drawing them exactly and connecting them to each other (via wire or net or what??), should they be just symbol or e.g i have to draw even what is inside circuit of a mixer or amplifier etc.. I shall be very much thank for your kind help
Question by lali2
IDEA 1. I've got the idea to create this kind of project where people nowadays being careless and misplace their item. So to counter this problem, i want to create a device which can detect the object/item within an area/radius of the receiver and transmitter. 2. This is not only for item/object but also can be placed on your children just in case they are away from you thus this device can alert you in sound, sight ( blinking LED ) , and vibration. PROBLEM 1. Is it possible to only use 1 transmitter and receiver? 2. Just in case for future uses, can compass be implanted in this device where it will always shows to the transmitter? 3. Currently programming are very hard for me, where can i get reference for programming this kind of device?
Question by Isaace11 | last reply
Greetings, I would like to know how to make a frequency converter. I want to convert the 2.4 GHz from a WiFi transmitter to one fourth or 600Hz which is in the newly freed up white space area for greater range. Anyone know where to find schematics for this, or make schematics? Is the circuit complicated? Thanks
Topic by NeuroPulse
Hi all. My friend and I bought 2 rc toys (1:18 scaled Ferrari F1) just for fun, but they work on same frequency (40.685 MHz) so we can't drive at same time. So i need some suggestions on how to change the frequency on one of them. The transmitter have quartz crystal, but receiver have only coil. I already tried solution "Modding Fisher-Price 72825 Formel Junior Fernlenkflitzer" found on this site, but it didn't work. I ordered quartz crystals from China working on (40.885, 40.985 and 40.285 MHz) and when i changed them in transmitter (one by one) the rc toy still reacted on commands from transmitter. Is there any other way to change frequency? Thanks in advanced.
Question by dule666 | last reply
I want to make a 1 watt violet laser, by using a 1 watt 808 nm laser and channeling the laser through a KTP crystal. Judging from my humble knowledge of second harmonic generation, That should create a 1 watt violet laser beam. Correct?
Topic by Nexoid | last reply