Can I reduce the frequency of the newsletter ?

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

Posted by aka.guf 3 years ago


frequency filter

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

Posted by guyfrom7up 10 years ago


Frequency driven speed for chase lights..?

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?

Posted by 3DPiper 4 years ago


Help converting 60hz to 50hz

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!

Posted by brandon3rdstone 5 years ago


Using 433M-Transceiver-Module-E32-TTL-1W-SX1278-SX1276-30dBm-LoRa-Long-Range-433MHz

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

Posted by laidlow7 11 months ago


frequency of composite video signal ?

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 ?

Posted by 11010010110 9 years ago


High frequency generator

I want to build a VHF (high frequency) powerfull generator for make an unusual form of lightning. It must produce microwaves 10 - 20 mm. length. Please, write here if you have any information about such generator.

Posted by 012345678910 9 years ago


Measuring oscillation of a multi tool

I have a harbor freight oscillating multitool that is advertised as oscillating between 10k and 20k oscillations per minute. In reality to speed control goes from 0 opm to an unknown value. I’m trying to set the tool to oscillate at 35 Hz. What is the best way to measure the frequency of the tool and set it to 35 Hz?

Posted by rednax718 5 months ago


How to make a frequency converter? 2.4GHz to 600Hz

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

Posted by NeuroPulse 7 years ago


Trying to create a circuit to allow me to adjust the frequency of AC power

I'm trying to design an EM field generator with adjustable frequency. I've got most of it figured out, but I can't seem to find anything about how to create adjustable frequency AC power. I've got two designs I'm working on, one that is DC powered and one that is AC powered, but the best I can do on either ends up with a 60Hz EM field. I'm looking for adjustable frequency, ideally from 0.1Hz to 50kHz, although I'll be pretty happy to even get any range of frequencies at all. The range from 0.1Hz to 500Hz is the most useful and interesting in particular for my purposes, but any help on figuring this out at all would be much appreciated.

Posted by PsychoHazard 7 years ago


Audio Detector

Is there some type of electrical component which detects high frequency sounds like those mosquito ring tones? I've looked around and seen things which apparently detect high frequency radio waves, but that isn't really what I want (at least I don't think it is). Thanks in advance.

Posted by brickzima 10 years ago


1 watt Frequency Doubled Violet Laser

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?

Posted by Nexoid 7 years ago


FM Transmitter mod help

Does anybody have any idea how to modify a car FM transmitter for an mp3 player so that it will transmit in frequencies other than the low and high extremes built into it? Also would it somehow be possible to make it transmit to all FM frequencies at the same time? If someone could help me out with this I would really appreciate it.

Posted by kurdiz 9 years ago


555 Timer Calculator

Hi everyone, I was looking around on the internet a while ago for a calculator for 555 timer circuits and couldn't find one that worked very well. Then I set about making my own in a Excel spreadsheet to calculate the frequency and duty cycle for me. I have decided to share it with everyone to help others. It is quite simple. Enter your vaules into the yellow boxes and get your frequency and/or duty cycle from the blue boxes.

Posted by qwertyboy 9 years ago


Need help changing an AC circuits frequency

Alright, so I have a question about an alternating current circuit I was working on.  The wall outlets I'm drawing power from are AC at 120V, and 60 Hz, but I need it to be 120V at between 60 Hz and 1000 Hz.  A variable system would be nice, but I'm not picky.  How would I do this?  Is my only option to convert the power to DC, and then run it through an inverter?  I would like to be able to do this with a small circuit I could build, something that would fit in a project box.  Any ideas?

Posted by Avren5 7 years ago


Frequency of Laser Tag guns

Does anyone know if Laser tag guns use infared LED's emitting at a certain frequency, If so what frequency/range of frequency

Posted by thermoelectric 9 years ago


Passive Amplifier Optimized for a Single Frequency

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

Posted by Josh_Blackburn 1 year ago


Can you piggyback RF communications on cellular transmit/receive frequency bands ?

My question is purely hypothetical and there is no immediate plans for any such application. But I was just curious is it possible to make use of the cellular frequency bands (as set out by a country's regulations and by the cellular providers) for some sort of covert type communication other than for voice, data or text types of cellular communications ? Would it be too difficult and complex to develop such an application that uses cellular radio frequencies or could it be done without too much concern for potential interference or the sharing of channels of nearby normal cellular transmissions ? Could such an application be developed without having to cross over many hurdles ? If this covert communications is possible would the cell frequencies used not reach the base stations of the wireless carriers as noise or can a peer to peer communications be possible by passing the base stations ?

Posted by victor43 2 years ago


Questions about computer stereos

Hi! I'm building a portable amplifier from old computer-speakers and I have a couple of questions about them. 1. How do I make the stereo-speakers mono the best way? 2. Is it possible to make low- and high-pass filters to a simple amplifier as the computer ones? I thought I'd connect one bigger speaker (a whopping 5" one!) to amplify the low frequencies and one small to amplify the high frequencies. This would work the best with a 1-channel amp. Thank you in advance, hope you understand what I'm looking for! P.S. Please move the thread if it is in the wrong category, wasn't sure if it suited better under "music" or "tech".

Posted by Henell 10 years ago


Body Fat Analyser

Have just been looking at buying some body fat analyser scales, and they are so expensive! £40 for what is essentially a few electronic components and a lookup table seems ridiculous. I think they use an electric pulse and then something to do with how the fat/water whatever resonates or something. As you see I don't have much to go on. Can anyone shed some light on how they measure these things and maybe even post an Instructable. Much appreciated.

Posted by evilad 10 years ago


TV giving off high pitch hum.

Well I recently inherited a old TV it is an SDTV and it is about seven years old. So I decided to test it with my computers osciloscope and using the microphone on it i turned the osciloscope on and there was one constant signal that went up and down about 3 or four KHZ every second or two. But when I muted the TV their was the normal background noise at about 1-7 KHZ but one signal that I found is about 16-17 KHZ and 5.94 DB, and when I turn the TV off it stops and that 16-17 signal disapers. So how do I get rid of this annoying high pitch noise?

Posted by jackillac92 9 years ago


Are there Phosphors that react only to specific frequencies of light?

Are there phosphors that only produce a color of visible light when struck by a specific frequency? If so, what would happen if this phosphor was struck be two beams of light at right angles, with each beam at half the "trigger" frequency?  If this would not result in an effective "trigger" frequency at that point, is there another method of achieving that effective frequency at a point, with two beams crossing at a single point, where the phosphor lies?

Posted by gschoppe 7 years ago


Request: Sound canceller / radio frequency canceller

Request: Sound canceller / radio frequency canceller. Here's the sound canceller, which is prices at around $30,000 Euros, and powers itself. (using radio frequency) http://www.digitaltrends.com/wp-content/uploads/2013/10/sono-technical-setup.jpeg Aditional request:  Radio Frequency canceller.  Ideally it would be something similar in concept, but would be able to cancel specific ranges also. Thanks.

Posted by WyattsAccount 4 years ago


Frequency help needed.

Does anyone know what frequencies of laser light can effectively and efficiently ionize normal air into conductive plasma?

Posted by Masterdude 8 years ago


Radio frequency program for computer

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?

Posted by Sedgewick17 10 years ago


Getting the Arduino to Convert analog signal from guitar into correct frequency

Hello Everyone, I was wondering if anyone can help me with a simple solution to my problem, I was to be able to get the sounds from my guitar into my ardunio and have the correct frequency be stored. I can get the guitar connected to the arduino and numbers come out of the serial monitor but they don't make sense, i need to have the correct frequency come up for each note i play, I have looked at a few solutions but being a beginner to this some go over my head or they just didn't work. Can anyone help me or point me in the right direction to be able to do this? Thanks  P

Posted by paddykoolster 9 months ago


sound-sensitive LED lights that respond to music, sewn into clothing

Hi there.   I'm new to the boards and off to the big festival in the desert next week.  Every year I make some kind of a flashing suit-- usually they are EL Wire -- which is kind of cool to dance in.  I recently took an Arduino course and I thought it would be great to make a jacket that reacted to sound.   Ideal:  Had a pot to deal with volume (of club music vs. speaking) and was able to power a row of LED's down each arm and possibly down the side of the torso. I have a board- I don't have time to program it- I'm wondering if anyone can help? I'm happy to sew it and all that stuff.  Yes, time is tight , but it doesn't have to be perfect! Let me know. There is some budget- not much but some. 

Posted by HUMUNCULUS 7 years ago


Changing the frequency of Ultrasound Massager ?

Is it possible to convert one of those existing portable Ultrasound unit thats use ( 1- 3 mhz ) to lower frequencies i.e.  35 - 350 khz  or build one form scratch ? thanks hele

Posted by hele 7 years ago


I need to repeat radio frequency in the 402MHz range.

I need to repeat radio frequency in the 402MHz range.  How do you build a RF repeater? I need to extend the range of a CGM (Continuous Glucose Monitor). It uses the MICS protocol.  Can you adapt an existing device?

Posted by arourke1 4 years ago


50% duty cycle circuit

Hello i want to make 50% duty cycle circuit frequency is no problem : any frequency thanks

Posted by aymanok 3 years ago


What frequency to use for a gaming steer?

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

Posted by Nimasa77 1 year ago


Why to use RF directional couplers in some measurements and control processes ?

I am an electronic engineer in the field of RF directional couplers, but I am puzzled about this question, why to use RF directional couplers in some measurements and control processes ? Today I come to this forum to turn to you to discuss my understandings are appropriate. Here are my personal understandings: RF radio frequency is referred to as RF current, it is a high frequency AC change electromagnetic wave short. Less than 1000 times per second changes in alternating current called low frequency current, more than 10000 times called high frequency current, and radio frequency is such a high frequency current. RF technology in the field of wireless communications with a wide range of irreplaceable role. In the electronics theory, the current flows through the conductor, the conductor will form a magnetic field around; alternating current through the conductor, the conductor will form an alternating electromagnetic field, known as electromagnetic waves. When the electromagnetic wave frequency is lower than 100khz, the electromagnetic wave will be absorbed by the surface, can not form an effective transmission, but the electromagnetic wave frequency is higher than 100khz, the electromagnetic wave can be spread in the air, and the outer edge of the ionospheric reflection, the formation of long-distance transmission capacity (Analog or digital) with high-frequency current modulation (amplitude modulation or FM), the formation of radio frequency signals, through the antenna to launch into the air, the radio frequency of the high-frequency electromagnetic waves.  Long-range radio frequency signal received after the anti-modulation, reduced to the electrical information source, this process is called wireless transmission. Wireless transmission developed for nearly two hundred years, forming a large number of users and product groups, but because of climate change and the impact of surface obstacles, can not transmit the perfect information. Modern human invention of the cheap high-frequency transmission cable (radio frequency line), in order to pursue the perfect quality of information transmission, taking into account the original wireless devices, wireless cable transmission began to pop. Resulting in the concept of radio frequency transmission. If your information source through the secondary modulation, with the cable to the opposite end, the opposite side with anti-modulation of the information source after the re-application, no matter how low frequency, but also radio frequency transmission, if there is no modulation anti-modulation process, The information source is transmitted directly to the opposite end of the cable, no matter how high the frequency, are the general cable transmission. SI --- Signal Integrity Signal Integrity PI --- Power Integrity Power Integrity emc --- electromagnetic compatibility Electromagnetic Compatibility rf - radio frequency RF emc = emi + ems EMI = Conduction + Radiation Emission SI: The Fourier transform shows that the higher the signal rises, the higher the amplitude of the higher harmonics. The MAXWELL equations see that these alternating harmonics produce alternating current at the adjacent line. And even through the space parasitic capacitance directly to another conductor, so these high harmonics is caused by radiation interference (emission) of the main factors; (that the simple point is that the signal rise faster, the more complete the signal, the better the signal quality, But for emi bad) . PI: PCB exists on the number \ \ analog area, high frequency \ 'low frequency region and other different areas and planes, if the partition is not easy to interfere with each other, that is, conduction conduction (conduction). Ps: Excuse me if I was wrong in words or expressions as I am a green hand in the field of RF directional couplers. I need continual learnings. What is your idea ? Do you agree with my ideas ? Any of your ideas would be highly appreciated. May someone would like to help ? thanks in advance.

Posted by maryzhu 1 year ago


Electric Lady - High Frequency Power Supply?

I saw an electric lady in a travelling sideshow. The type where she throws sparks from the hands, makes paper  burst into flames and causes bulbs to light by holding them. I'm assuming they are using a high frequency power supply (very low amps), and I was wondering if anyone has built one and if there are any good schematics on line?

Posted by Divet 7 years ago


Music Mashup: Anyone else looking to deconstruct songs layers they can mix and mash?

Hello All. I am new to Instructables and would like to hear some feedback on my topic. With all the technologies available today does anyone know of an all encompassing program that can break down (deconstruct) songs into layers? As in break back down into the layers used to make the master recordings. So you can create your own mash ups? Say I want the guitar riff from AC/DC and a trumpet "layer" from Dizzy Gillespie and some singing from Madonna. Slow them or speed them up till it works for me. Not trying to steal others people stuff and publish it/ sell it, just mix and share for personal.  Please reply with your work if its in a studio, engineer, singer, label or software developer etc. Much Appreciated,  CoolKat AKA Yellowshades (Entertainment Marketing)

Posted by yellowshades 5 years ago


speaker drivers

I'm looking for speaker drivers within 40mm-50mm and a full range frequency response of about 0-25khz But! i cant find any manufacturers within the uk at a cheap price or decent frequency range btw its for a headphone project im working on :D All help greatly appreciated (:

Posted by 00mike000 9 years ago


How to make arduino react to a certain frequency

Hi, I'm new to arduino, and I was wondering if its possible to program arduino to react to certain frequencies. In other words, I was wondering if its possible to program arduino to go off if you have a certain note played. Also, as a side note, I was wondering if its possible to reduce a voltage. I have an amplifier that runs off 24 volts and I was wondering if I could redirect some to power a 12 volt bluetooth chip? Thank You for all your help!

Posted by Fozzibehr 4 years ago


Recording ultrasonic sound

I looked up at bat detector, a device that converts ultrasonic signals into audible sounds. Most bats produce high frequency calls which are often higher than a human ear can pick up. A bat detector picks up the frequencies and then converts the sound into a lower, audible frequency. I was thinking if I could get a bat detector, I use it to capture the ultrasonic sounds.While bat detector could pick up these high frequencies, it would be interesting to see how it will pick up the faintly heard, to human ears - sounds of the industrialised areas/city or even at isolated/quiet areas. The bat detector I want to use is this - http://www.magenta2000.co.uk/acatalog/B ... _Bat4.html I'm thinking of hooking up the bat detector to a digital recorder and a binaural microphone and capture the sound through those equipments. I would greatly appreciate your suggestions/opinions on this matter.

Posted by drifterocean 4 years ago


Trying to build a square wave generator (high frequency) and H-bridge

Hi, I was wondering if someone could help me out at building a high frequency variable square wave generator. Specs: 100kHz - 1Mhz (better if I can get up to 3Mhz), 5 to 20V, square wave. Right now I have a LM555 timer. I have read online that I can get it to run at maximum 1Mhz. I don't know what I'm doing wrong, but I can't get it to output at higher frequencies. Also, does anyone know of a good H-bridge circuit schematic that could output 24V pk-pk at 3A. I will be using the signal from the square wave generator to feed to the H-bridge, therefore, is there a H-bridge design that can handle high frequencies? Or, is there another driver circuit that I could use instead of a H-bridge that could do the same job or better?

Posted by sonny301 10 years ago


Amplifier

How much maximum frequency and maximum power we can get from an amplifier. I mean what is the latest technology about amplifier.

Posted by m_uamir72001 5 years ago


Keepon

Anyone think they could build one? I've been thinking about it.I think what it does is compare 2 different freuqencies (of the song, I'm just going to totally ignore the camera in the eyes part, just want a dancing yellow robot) and depending on the difference of the frequencies it moves a different amount. It probably only moves to lower frequencies, only to beats of songs and not the singing.anyone up to it? I might try...

Posted by guyfrom7up 10 years ago


Pond/Water Misters/Foggers

Does anyone have a pond fogger/mister and knows what frequency (Hz-Hertz) ultrasonic thing vibrates at.

Posted by thermoelectric 10 years ago


I need a fairly easy 500 Mhz to 3 Ghz signal generator schematic

It needs to be fairly simple to make, my resources are a bit low again, and it doesn't have to generator a lot of different frequencies, just one or so within the range of 500 mhz - 3 ghz. Everything I found on line was either more complex then building a 40 meter transceiver, or was ready built and only cost $200 + Even if there was a source I could purchase, for under say $30, I would take that too. I need it to test my newest rig. I don't want to have to resort to something like this project here...

Posted by Goodhart 9 years ago


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!

Posted by Xmortx114145 5 years ago


audio / light frequency matched color organ

Hi there, this is my first time to the forum! I've been doing some searching, as I would like to build a colour organ but further differentiate b/w audio frequencies and the circuit they trigger. Bascially, I would like to take an audio signal (preferably from a mic) and use it to trigger lights based on musical notes. So basically, every A (...110 Hz, 220 Hz, 440 Hz...) would light up a certain circuit, and on for all 12 notes of the musical scale. Of course, I would not limit the response to only 440 Hz for example but slide it to the edge of the adjacent notes' frequency, with 440 Hz occupying the median. So, I'm wondering what components are necessary to make this happen. In a recent DIY project I saw there is rough split between 3 frequency ranges (bass, mid, treble). If I were to approach it with the same design concept, I would need (8 octaves for example, at 12 notes each) 96 different circuits to run. I'm not opposed to using a PC with some kind of digital signal processing to take the place of these circuits. Also, I want to run the lights on 120 V power for non-LED lights. My experience in circuit building is nil, but I've consulted circuitry diagrams before for other reasons, so I'm not totally green. I'm computer savvy but only to a certain extent. Not much programming experience save for a 1st year university course. I have an analog to digital convertor, but that's it for components.  Once I have the digital signal in, where do I go from there?  I'm assuming I will need some kind of software to convert via fourier transform to a frequency domain signal then filter all the frequency ranges from there.  I assume I would have a digital out signal to a switching circuit board with 12 outs to control the power supply to the lights.  Can anyone point me in the right direction?  Many thanks!! HQ

Posted by H.Q. Tinwhistle 6 years ago


3D or correctly 2.5D engravings on wood with a CO2 laser

Due a lack of correct forum sections I just post in the tech department, hoping the right people will find it ;) I did some tests with my CO2 laser cutter to find out how good or bad it works for 2.5D engravings. Turns out not too bad really. But during those tests I often noticed that I have areas where the wood is burnt while in areas with other power levels the wood is vaporised without charring, looks totally clean. So of course this meant further investigation on the topic but to my surprise my Google skills seem to get rusty as I could not find anything of use. As I am still planning to do a full Instructable on the topic of 2.5D engraving it was time to do more detailed tests myself. My machine uses an Arduino Mega as the controller, running on a modified MarlinKimbra release, so I had no problem adjusting all required parameters. Here are some of my findings so far: Once the power levels are high enough to do real damage to wood instead of just darkening it, there are levels that just vaporise the wood. I did not test the full power range but there seem to be several "sweet spots" for the power, above and below the wood will be burnt instead of a clean vaporising. Next step was to check this behaviour with changing PWM frewunecies for the laser firing. Started with a know power level that vaporises and adjusted only the PWM frequency. Lowering the frequency soon caused charring, increasing the frequency had very little effect. Next was a lower power level that with the original PWM frequency would charr the wood. Here lowering the frequency caused more charring, at quite low frequencies to the point that the kerf suffered massively. Increasing the frequency again allowed to find a sweet spot where the wood would vaporise rather than burn. So I am wondering if anyone else has done tests in this regard or knows of any links with more info?

Posted by Downunder35m 2 years ago


High Frequency Alternators

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!

Posted by ElectricUmbrella 9 years ago


Simple and CHEAP voting system - AM?

I'm a teacher, and I have a little (but not a lot) of money to spend. I'd really like to buy something like a Quizdom voting system, but with anything up to five classes of 26 running at once, it's just not financially possible. Which got me thunking... AM radio transmitters are cheap to build right? I've seen one using a 555 timer and an NPN transistor - these cost pennies - use to transmit voice. Could I instead transmit a BEEP - or high tone or something - each timer on a slightly different frequency? And have a single receiver which then listens across this frequency range and identifies which frequency is transmitting the tone or signal and feeds that back into... PC, Arduino, Raspberry Pi? Range would only need to be like 5-10m.

Posted by ohowson 5 years ago


dc inductor

Do inductors work with pulsed dc? like would they become more resistive with frequency? Or would they do nothing because it's not ac and the electrons can't "bump" into eachother.

Posted by guyfrom7up 10 years ago


Another theory...

I was wondering if this is doable, or even practical for that matter. So I read up on lasers and from what I can tell it is a form of light in which the wave frequencies are perfectly aligned. So I was wondering if you aligned UV light wave frequencies, would you get a laser that would burn stuff, and not to sound morbid, but in high quantaties, kill people. (Only for the sheer exitement of figuring something out am I posting this. I do not in any way want to kill someone.)

Posted by vroom...vroom... 6 years ago


can you help me build a Solar powered wireless camera

Hi guys,I have a little project here for some of you that I would like to find out how to go about making.i bought a wireless mini cctv camera Camera apparatus: 1/3 1/4 picture sensorSystem: PAL / CCIR NTSC / EIAValidity pixel : PAL:628*582 NTSC:510*492Picture area: PAL:5.78*4.19mm NTSC:4.69*3.45mmHorizontal definition: 380lineScan frequency: PAL / CCIR: 50HZ NTSC / EIA: 60HZMinimum illumination : 3LUXSensitivity: +18DB - AGL ON-OFFPower output : 50MWFrequency output : 0.9G/1.2GFrequency control : Adopt CPU frequency lock the wreath to control, with high frequency stabilitySize: 20*20*20(mm)Deliver the distance: 50-100MVoltage : DC+8VCurrent : Current :Power consumption : <=640MWWhat I want to know how to do is to power this by solar (al the time) so I can leave it unattended permanently without having to keep changing the batteries.i dont need to power the reciever by solar just the camera but if you like you can do that too.Any help would be greatly appreciated.Oh and I know nothing about capacitors and the likes so try make it easy for me : ) i hope you can make sence of the specs cos i cant. :)And the smaller the better.Thanks guys

Posted by TotalNOOB 11 years ago