How to Tell if a Webpage Sucks

Somewhat amusing: How to Tell if a Webpage Sucks.And yeah, we try not to suck. If we accidentally do you should tell us. :-)

Posted by canida 10 years ago


Teaching Middle School Through Instructables

I am a junior high math and shop/technology teacher. For years I have been wanting to develop a math program that uses as much hands on as possible.  Like all teachers, I have developed a few projects, but just don't have the time to develop all the activities needed to cover an entire curriculum. I would love to correspond/collaborate with others (including non teachers). Email me directly if you are interested.  mikemckay@pwsd76.ab.ca

Posted by mikemckay 6 years ago


Trailer (from old truck) Differential can Seize?

Do i recall correctly? Can the wheels seize up because of an issue with the differential?

Posted by Toga_Dan 2 years ago


Knex differential

I created the differentials a while ago. Larger versions are possible without any modifications of the basic pieces. This version is designed to be smaller in diameter than the main drive gear, requiring a modification to that gear.

Posted by Speed8ump 10 years ago


can we avoid the usage of a differential in an automobile? Answered

I wanted to know can some how avoid the usage of a differential in an automobile?

Asked by srujithcool 8 years ago


Differential Effect? Answered

I'm building EV with 2 individual motors on the rear wheels and How do I control the speeds on each wheel for the differential effect? Thank you, Eliseu Candido.

Asked by Eliseu Candido 9 months ago


How to make a tricycle differential?

How do you make a tricycle differential so that both wheels can be driven yet and rotate at different rates when going around a turn?  This would be for a human-powered tricycle.

Asked by rpp618 7 years ago



How to develop electronic differential for articulated rear drive e-trike using the steering angle in Matlab/Simulink?

One wheel at the front and two wheels at the rear,steering mechanism

Asked by SachinK114 1 year ago


How to generate a fixed differential voltage dependant on a voltage relative to ground?

What methods can I use to generate an accurate & precise variable differential voltage that's dependant on the output of a +-10V DAC? I tried to use a resistor with a small variable current sink using the classic opamp+NPN design, but no design I made would sink current below 1V. I need it to continue sinking current down to 0V, I do have a negative supply rail avalible. (I think my last question was a bit TL;DR for some, so this is a shortened version of that.)

Asked by -max- 2 years ago


How to maintain speed of an electric vehicle with an electronic differential when vehicle is cornering at maximum speed

As the motors are rotating at the maximum speed, how to increase the speed of the outer wheel in order to maintain the speed of the vehicle ?

Asked by SachinK114 1 year ago


extrusion of area between the star and the rim? Answered

The instructions say to chose the space between the outer rim and the star. When i try, it selects the entire surface. How do I differentiate the sketch from the surface? How do i differentiate the sketch from the area between the star and the rim?

Asked by LL11 1 year ago


differential amplifier tech

Hello, I'm following a circuit diagram for a current monitor that uses an op-amp as a differential amplifier. Connected to V- and V+ on the amp are the positive and negative leads of a 10mH Inductor that senses the current (as much as 9A) passing through an insulated positive line. The gain on the op amp, I'm told, is 220. If I calculated this correctly then at 9 amps in the insulated wire, 0.09V should be produced by the inductor and there upon entering the V+ lead and -0.09V in the V- lead for a differential of 0.18V which gets amplified to 39.6V. However the voltage source that powers the op amp is only 9V. So question # 1: Did I break down the math correctly? question #2: What happens to the excess voltage from the gain? I am getting all of my op amp information from wikipedia. I've never used an op amp successfully before.

Posted by watchingmachine 10 years ago


arduino vs raspberry pi? Answered

Can somebody help me in differentiating between arduino and raspberry pi

Asked by vedantbansal 1 year ago


Chrome vs Vegetable tanned leather? Answered

Can you differentiate the two by just looking at them and feeling them?ThanksJas

Asked by JasMadhavan 1 year ago


How does lock protection work on HVAC fan Answered

The mpu detect the rpm and if no match it will stop the motor how to differentiate if it is from a bad motor or a bad mpu circuitry  

Asked by jma123 6 years ago


Is there any sensor that can detect human skin?

I am working on a project that  involves detection of skin. The sensor should be in such a way that it should differentiate human skin from other objects like wood,plastic,metal.

Asked by krishnaramya 1 year ago


A good explanation and example of a USB interface circuit?

 Every USB circuit I come across seems to be about the same with D- and D+ clamped to 3.6 volt with a zener diode. These wires are then passed to uC's io pins. Am I correct in thinking this setup doesn't take advantage of USB's differential signaling scheme? Because I thought an op-amp was needed for differential signaling. Does anyone know of a good resource, with circuit examples, that explains how USB transceivers work? I'm not interested in the actual protocol (NRZI, and all) I already understand most of that, what I'm really looking for is circuit level stuff.

Asked by hacim 8 years ago


Large motors actually come in both sexes - AC and D.C.​?

Really, don't you think you should differentiate between AC and D.C. In the title? Large motors actually come in both sexes - AC and DC

Asked by itsmescotty 7 months ago


Motor assisted pedal powered rail rider

I am trying to build a 2 person human powered Vehicle that is also motor assisted, I need a way 2 people can pedal at diffrent speeds and drive the same axle. What I think I need is some sort of differential gearbox. What Ii need to know is: Is there is a differential that can take 2 different input speeds and have one output? If it did and I also pushed it with a motor would the wheels spinning feed back though the gearbox and send the pedals spinning like crazy? Any help or advice people can offer would be great.

Posted by BillP55 6 months ago


Do capacitors have positive and negative terminals?

What are electrolytic capacitors? In what way they are different from normal capacitors? The charge on a capacitor depends on how i connect it to battery,but electrolytic capacitors have one long and short terminal to differentiate between positive and negative terminal. Why?

Asked by deepakmurali 6 years ago


How do I calculate total lateral forces in the tyres of a 3 wheeler?

Are the lateral forces and lateral slip angles same for rear wheels and front wheel in a front (one wheel) steered rear drive vehicle?

Asked by SachinK114 1 year ago



Peltier-element: Limiting its heat by tapping the power?

Hi I have a question based upon logics and the function of a peltier-element. we all know, that you can supply power to a peltier-element to raise the temperature on it one side and lowering it on the other. So it increases the differential. Now: If we heat the "cool" side and try to radiate the heat off the hot side (eg cooling it a bit), we can get a small amount of energy off the peltier as electrical current. The current depends on the temperature-differential: The bigger the more. OK so far. Nothing new. But what made me think was the fact, that you have 2 opposite states: Heat Side C and cool side H --> Get energy out in proportion of heat-differential. Put energy in --> Side C gets cooler and side H gets hotter in proportion of energy supplyed. By getting energy OFF the peltier, you in some way, redirect some parts of the heating-energy to the electrical-output. Also that is nothing new and we all know that since energy cannot be generated but only converted (in our case from thermal energy to electrical energy). Now what puzzles me is: Does it actually affect the temperature (-differential) of the peltier, if you get energy off it? Lets imagine the following experiment: - You build something like in https://www.instructables.com/id/Candle-Powered-Electric-Candle/ - Now you disconnect the load (lamp) and measure the temperature on the upper side (Away from the candle). - Wait for a steady-state when the upper side doesn't get hotter - Now turn on the lamp thus redirecting a bit of energy away from the peltier. - measure the temperature again on the upper side. Does it lower the upper temperature a bit? of course it wont be lower than the unheated state. But lets say the steady state was 55°C. Would it be like 50°C if i switch on the lamp?

Posted by Orngrimm 5 years ago


How do I figure out the cost differential between turning on an inefficient furnace and using oil-filled space heaters? Answered

The big deal is that this furnace also heats the upstairs unit of a duplex, which i also own and rent out to my brother in law.  the deal is that he spends maybe 5 nights per week at his girlfriend's house.  so, if i turn on the furnace, all of the heat that goes upstairs will be wasted.  i'm interested in learning how to measure energy usage and learning how to determine the usage difference between running the furnace, which is about 50 years old and runs at about 50% efficiency and three pretty standard 7-fin oil-filled space heaters.  the flat in which i live is about 800 sq.ft. and the upstairs space is about 600 sq.ft.  the windows are old, but are covered with plastic shrink film for better insulation.

Asked by hobbssamuelj 8 years ago


Infinitely Variable Transmission?

Ok, so I have been looking at this thing called the D-drive and it inspired me to come up with my own IVT design which was solid gears for max torque handling and still could change speed and direction easily and smoothly. This is what I came up with and I would like to hear your opinions on it.  It starts with input to a differential, one side of which is inverted and the other isn't before returning to a second reverse powered differential.  The two sides are slowed using a fluid braking system which has a rotor powered by the side's drive-line, and a flow limiting valve to apply resistance.  As one side slows the other accelerates.  When there is no brake power on either side you have reached a powered neutral, and when the second side is braked the direction changes and accelerates. So, will it work? How practical is it? Are you going to say it sucks, then steal my idea?

Asked by jj.inc 6 years ago



How do include instructables activity in a resume? Answered

I'm currently unemployed and have made a few instructables. I feel like making them demonstrates various skills that an employer might desire and shows that I'm not inactive while unemployed. Having said that, how would one go about including instructables activity into a resume as a differentiating factor? Examples? Thank you!

Asked by vreinkymov 6 years ago



tesla turbine question.? Answered

I was wondering, if i make a tesla turbine with big a** blades, then completely enclosed them, and finally covered the enclosure with heat sinking fins would i be able to develop a heat differential between the center and the outer? and could i make it colder/hotter by allowing the air to turn in on itself at the bottom? how much could i expect, a few degrees in Fahrenheit? or could this possibly get down to -120 degrees Celsius?

Asked by waldosan 7 years ago


IR Reflective Sensors for Arduino?? Answered

I just ordered a bunch of reflective sensors... Similar to the sparkfun one (I've not decided digital or analog yet)...I'd like to connect them all up similar to the Pololu Arrays...  I want to hook up like ~30 and read them individually... How do you differentiate so many inputs into the Arduino? Is there some similiar code to work from? cheers!

Asked by hydronics 6 years ago


Please explain Theo Jansen Mechanism?

We all have seen the Theo Jansen Machines and they are JUST AWESOME! I'm trying to build one. What is the the theory and mechanism behind Jansen's machines? Please explain. [Unicode Symbols for your convenience: Degree= ° , Half = ½ , Third = â��, Fourth = ¼, Three Fourth = ¾ , Integral = ∫ , Differential = ∂, Delta = Δ , Square = ² , Cube = ³ , Square root = √, Cube Root = â��, Infinity = ∞, sum = ∑ , Therefore = ∴, Because = â�µ,]

Asked by sarveshk 6 years ago


Need help programming an Adruino to function as a solar differential controller Answered

Hi I need help to write a program for an Arduino to allow it to function as a Solar Differential Controller (SDC). An SDC simultaneously reads the temperature of two different elements,1) the water inside the thermal storage tank and 2) the inside of the solar collector. When the sun rises in the morning it begins to heat up the inside of the collector. When the SDC senses that the collector is a few degrees warmer than the storage tank it signals a circulation pump to turn on to circulate water from the tank, through the collectors and back to the tank. When the sun starts to set in the evening and the collector cools to within a few degrees of the storage tank, it signals the pump to shut off. So basicly I need the Arduino mega 2560 to read the temperature from two DS18B20 digital temperature probes. When one of the probes shows a reading 5oC higher than the other, the Arduino changes an output to high. When the higher probe's reading drops to within 5oC of the lower one, the Arduino changes the output back to low. I don't even know where to start really, this programming is way over my head. Any help would be appreciated. This program is for a large project I'm working on for this site and any help you give me will be credited to you. Thanks.

Asked by EcoMotive 5 years ago


Why is that little solar panel sneaking about...

That little solar panel that popped up behind robot, it was a link before but now it's in a sensible place...  Actually it was a little advertising easter egg earlier but now it's sitting there in its rightful place all smug and whatnot, lording it over me like some kind of photovoltaic fuhrer, thinks he's so good with his ability to turn photons in to voltage differentials, like I can't do that when I try. 

Posted by killerjackalope 7 years ago


Lm317 to a 48v ac powersupply, or how to lower the voltage 10 v. Answered

So i have this transformer that puts out 48v ac. I want to make a variable power supply, and it should put out 7 or more amps. I could use lm317 with a bypassing transistor, but lm317's maximum input-output voltage differential is 40v,  so what should i do? If anyone has ideas how to lower the transformer's voltage 10 volts that would be great.

Asked by jukees 5 years ago


How to power an opamp(with -5v) form USB?

I`m making a dac+amp with usb input and headphone out. I`m powering it from USB. The USB controller and the DAC uses 5v and 3.3V, but the opamp(LM4562) uses +-5v. How could I get this differential voltage form the 5V of the USB, even if i get less current. If you can give me a good IC, it would be great, but if you can give me even a schematic (+IC) would be awesome.

Asked by fmada 5 years ago


How oscillators work?

Why oscillators like wien bridge oscillator or RC phase shift oscillator gives only sinusoidal waves instead of triangle waves or square waves of particular frequency. Please dont explain about multi-vibrators . Also please say how to differentiate between low frequency oscillator and high frequency oscillator. By using any value of R(resistance) and C(capacitance) i will be able to get any frequency(high or low) by substituting in respective formula. But what makes one to judge a oscillator as high frequency or low frequency.

Asked by deepakmurali 6 years ago



Assistance in designing an automatic room light controller?

I am trying to build an automatic room light controller that will turn on a lamp when a person enters a room and maintains it in the on state as long as the room is occupied. once the room is empty, the lamp will switch off. I intend to use a PIC for this project, together with an infrared emitting diode and phototransistor for detecting entry and exit. But my major problem is making the circuit direction sensitive. How can I differentiate between entry and exit? I would really appreciate any help I can get. Thanks

Asked by 8 years ago


Is there a simple way to test the air flow/pressure inside my HVAC fan housing?

Is there a simple way to test the air flow/pressure inside my HVAC fan housing? Perhaps some kinda guage I can attach to the blower unit of my fan box for the HVAC? Why? I'd like to test with new filter and then old, to determine when it needs changing. so, I'm looking for a simple, cheep differential pressure gauge or some means to tell if the filter is dirty and thus constricting the flow through the fan unit.

Asked by gereckes 5 years ago


Any Maple alternatives?

I need a something that plots graphs (three-dimensional is better), solves differential equations and counts integrals - Maple would be ideal - plus I think that learning to use it is a nice constructive thing to do in the summer before starting university, but it costs a lot more than I can painlessly pay...  Any ideas? Probably some older versions are free or cheap, or there are any other programs? I looks like I'm only going to use it in the summer as they probably should give something to students... To be more specific, I'm trying to learn GTR and calculate some geodesics.

Asked by gruffalo child 5 years ago


What can you tell me about Stirling engines?

I'm interested in using a Stirling engine in a solar energy project. From reading around and doing some numbers it looks like I'll need around 1.5 kilowatts, and something in the vicinity of 30% efficiency or upwards would be nice, though I realise this may be overly optimistic. So, what's available, how much will it cost, what temperature differential is ideal, how big and heavy are these things, etc. Any info I get would enormously helpful. Cheers, Daniel.

Posted by SolarFlower_org 9 years ago


Detect finger movements while playing a piano?

I'm planning on generating the sheet music automatically while playing  a piano. However i need to first find a method to differentiate the notes played by the left hand from the right hand. My lecturer suggested i find out the points in the wrist where pressure is exerted when each finger is flexed (left hand). Is there a way to do this simply? Or are there any products, such as wristbands with in-built sensors to sense when a finger is flexed? I only need to know how many fingers of my left hand are used at a particular moment while playing.

Asked by MissyJJ 5 years ago


Accurate Variable Current Sink? Differential Voltage Reference?

Some background: I have recently aquired a few really nice (and really heavy!!!) LAMBDA power supplies, The largest one supplies 24V, and up to 9A, but has annoying foldback current limiting, which causes the output shut off when even a short period overload (like inrush current) is detected. What I want: I would like to modify this power supply to give me (ideally) completly variable 0-15v dual rail voltages & 0-5A adjustable current limit, & I would like this to be controlled with arduino so that I can use a nice LCD display and control the supply remotely with a bluetooth or wifi app, and possibly do some data logging which could come in handy for energy measurements and stuff! My current PSU design: The schematic below is what I've currently built in LTspice. Both the voltage & current regulation work. The voltage across the (+) and (-) inputs of the current error amplifier should be the sum of the voltage drop across the shunt resistor and the voltage drop of a voltage reference, so when the voltage on the shunt resistor exceeds the voltage of that reference, the op amp will start to limit current by reducing the bias voltage on the pass transistor. This V_ref needs to be both variable and accurate, but since this V_ref is a differential voltage between the output of the pass transistor and the input of the error amp, I came up with the clever idea to use a resistor there and a variable constant current sink. That way the constant current through that resistor results in a fixed V_drop across it. With a bit of fudging around with it, I was able to make it work. However, I need to replace that "ideal" current sink with a real one. I tried using the classic NPN-based one, but it wasn't good enough. I then attempted to make the slightly improved version of that current sink with a spare op amp, although this worked, it would stop pulling current once the voltage fell below what was being maintained across the small resistor. The REAL question: Would anyone happen to know how to make a really accurate and variable current sink? Maybe if this is not such a great idea, what other methods can I use to generate a fixed differential voltage?

Asked by -max- 2 years ago


Led Clock, Need Help. Using Arduino

I want to make a clock where there is a led blue or clear marking each hour around a circle, the led is on for that hour and then moves to the next led in the circle for the next hour.  pretty simple.  it will look kind of like an analog clock except without the hands.  for the minutes, i want the same leds as the hours to light up but since there will only be twelve, it will only be accurate within 5 minutes.  the minutes need to light up less bright that the hours so that i can differentiate between the two.  I have an arduino uno, breadboard, resistors and leds.  Please Help!!!

Posted by earthswater 6 years ago


Best way to control many seperate but identical devices remotly?

I need to control many (hundreds to thousands) small devices within a meter by computer so that i can program them and control them simultaneusly. cannot put a microcontroller in the devices, whats best bluetooth, radio waves, infra red? Any sujestions? I need to make the interface to the transmitter USB. I also need to recieve measurements from each device in real time and be able to differentiate for both the data and the devices since i will be controlling them and also recieving information from them. Any ideas?

Asked by amelius 7 years ago


Violin tuning issue: Don't know how to tune D string Answered

I know how to tune everything but the D string. I keep going up and down with the fine tuning, but to no avail. Here's what I've got: -Violin is made in China, but it's somehow better and lasted longer than most violins here in the PH (Philippines) -I have a pitch pipe to assist in tuning, but when I hit D, it's somehow muffled (in a way) and I can't hear it clearly, so I can't differentiate between what I'm playing on D at the moment, and the pitch pipe output.

Asked by nutsandbolts_64 6 years ago


In what electrical objects can I find op amps? Answered

Hello again, I'm searching for good op amps. They don't have to be power op amps, but it would be nice if it also had some protection circuits like a current limiter. It needs to take at least 25V differential between the negative and positive supply voltage. It should be a chip with at least two op amps inside it. Are there any broken electrical items that have these inside? I know they are 'used a lot' but somehow I don't find them often. Greetings, Electorials

Asked by DELETED_Electorials 6 years ago


Feature Request: Repeat Ible Alert

Sometimes I see a new Instructable (usually by a first-time poster) that is very nearly a repeat of an existing Instructable. I think that if people knew that their idea had already been I'bled before they published it, many of them would stop at that point (which would be unfortunate) but SOME of them would make the extra effort to differentiate their work with some new or novel approach, or better directions/photos/results, etc. If you do a "view Instructable>>" while you're building one, the "Related" sidebar of similar Ibles shows up, but it doesn't appear to be intelligent at that point. That might be a simple fix. Or maybe as soon as you fill in the "Name This Instructable" box, the "Related" sidebar would appear. Just a thought. James

Posted by Scubabubba 9 years ago


bikeframe to trikeframe

Hi all, ok here is my plan, any advice is welcome and appreciated. I am not building a bike frame, however I am converting a bikeframe into a trikeframe. The first image attatched is a bike i have that i have stripped down to the frame, seat and bars. the second image shows a hudson carrier trike from the 1930s. So i want the bike i have to have a chassis like the hudson carrier. i plan to have a differential encorporated into the chassis. Does anyone have any ideas about building the chassis: which type of metal? where to get metal from in UK, weather using an existing chassis and encorpating it into the existing frame is good; possibilities, ideas, suggestions any discussion is welcome, thanks for reading my post!!! Nicky

Posted by nickyrai 10 years ago