I need some help in this homework. Foil length of strain gauge is L Resistance of strain gauge is R Equation is deltaR/R=0.485(deltaL/L) the strain gauge is given a strain of X%. The question says to calculate the change in resistance on the strain gauge. My problem is that i don't understand the X% strain. I'm not asking for answer, just want to know what the X% strain means

Question by ARJOON   |  last reply

### Auto body help

I need some help here and I hope that there is someone that can answer this question. I have a 2003 Toyota Tacoma and I want to add some bigger fender flairs on the truck, I want to use what are called pop rivet nuts. The pop rivet nuts are inserted just like a pop rivet but it has a nut on the back of it so that you can use a small bolt. The screws that came with the fender flairs are called self tapping screws and they seem to wallow out after time. I need to know what the thickness of a typical fender is so that I can order the right pop rivet nuts. The pop rivet nuts only come in sizes for gauge metal. Does anyone know what gauge a finder is so that I can order the right pop rivet nuts. Thanks for any input.

Topic by fishhunter1957   |  last reply

### electromagnet gauge makes buzzing noises?

Hi, i've been working on a project that involves reusing the electromagnetic needles commonly used in 90's era ford gauges. i can get it to work fine, but it seems to cause a buzzing noise as it is doing the work. there are three pins, ground, power, and signal. right now i just have it working off of 5v. when i have it going, and you hold the needle with your finger, you can feel it vibrating. i'm using an arduino nano, a npn transistor, and the gauge with a PWM output. do i just need to put a capacitor in? or how do i keep it from buzzing like it does? its not a loud buzz, but you'd notice it if you were in a quiet room.

Question by zack247   |  last reply

### using a strain gauge to make a load sensing pedal

Guys, I want to use a strain gauge as a load cell in a driving game, where the brake padal is force sensitive not movement sensitive. Currently the pedal is set up with a rotary potentiometer which has three connections and is basically the same as a PC joystick, complete with the circuit board. The strain gauge is one of the resistive film type with two connections, and the resistance will vary with the extension of the gauge; however, I don't know how to link this to the joystick circuit hardware, as one of the connections is missing Any ideas?

Topic by lesthegringo   |  last reply

### I would like some assistance in designing a digital LED display vacuum/boost gauge for a turbo application. Answered

Hello!   I'm new here. I would like some assistance in designing a digital LED display vacuum/boost gauge with both a linear LED display as well as two seven-segment display modules.   I plan to use a standard automotive MAP sensor to provide the -30Hg to  +30psi signal.   What I envision is having the two seven-segment displays sit next to a row of 28 green LEDs for vacuum to -28Hg, 7 yellow LEDs for pressure from +1psi to +7psi, and 8 red LEDs for pressure from 8psi to +15psi that light up incrementally as the pressure increases or vacuum increases from a center point of zero (clear LED always on).  The problem is that I have absolutely NO idea of where to start other than the layout of the LEDs.  So any help would be appreciated. Thanks! Skullmaster20  (Chris) Edit -----  This is a drawing of what I'm trying to create, and a picture of what I'm going to replace.

Question by skullmaster20   |  last reply

### Can speaker wires be used for power transmission?

I am making my own bicycle light and I decided to use 18 gauge speaker wire.  Speaker wire works well because positive and negative are glued together in the insulation.  It makes for a cleaner wiring job.  I am using the RCA plugs as well.  The light runs at 4.2 volts and 1.5 amps.  Speaker wire is not designed for power transmission but I can use it for that purpose can't I?  Do RCA jacks have a significant amount of resistance?

Question by Noblenutria   |  last reply

### single led light bulbs?

I have some single led light bulbs. I want to string 113 of them. they're 1.5 watts each and 12dcv. what transformer and gauge of wire should I use? G4 socket. there's 24 led's in each light. they're pretty small.

Question by ron.stone.733   |  last reply

How can I use 2 of the "Cracker Box Amp" circuits to drive standard analogue gauges from the audio out on my computer.  I will use 2 gauges, one for left channel and one for right. I want the gauge to show the amplitude. If I just wire up a gauge to a channel on the audio out then the needle will simply move as if it were a speaker. As I said before, I want the gauge to show the amplitude.

Question by physics_dude   |  last reply

### How many strands of 17 gauge wire twisted equal a 12 gauge wire (approx)

Hi,  I need a 12 gauge wire for the positive side of a small perimeter electric fence. However the only size aluminum wire they sell locally and I bought was 17 gauge wire. My thought is to twist the entire length of two or more strands of the 17 gauge wire together to equal the 12 gauge wire (approx)  How many strands of 17 gauge will it take to do so? One more related question while I'm at it. Does the twist have to be a tight twist or can it be a loose twist? Tight meaning a lot of twists per foot, loose meaning something like 4-6 twists per foot. tia - chase -

Topic by -chase-   |  last reply

### water inline low pressure gauge at output

I don't know if they sell them , water Inline  pressure Gauge  made for 5 lbs and under, or is there an easy way t to make one, doesn't have to be inliine, it just needs to  measure the psi at 5 gallons and at 1 gallon.. Even A balloon that burst at 3psi would be good/. it is for a medical device. i spent the last year going crazy cause it was defective brand new.  it was putting out the correct  pressure at the start, 5 gallons, at the half way point it was putting out about half the pressure, didn't know it, almost had  surgery because of the poor results thanks for any ideas

Topic by escapefromyonkers   |  last reply

### what fuse to use or gauge wire to act as a fuse?

Im making a battery powered coil gun.. each coil draws about 180-200 amps of a pulsed current. I want to know what fuse ratingi should use to protect the circuit.? or if there aint such a fuse.. what gauge wire should i use as a fuse..

Question by icey.hood   |  last reply

### How are we able to know the variable of a Strain Gauge? Answered

Hi, for a school-project I need to measure the weight of an object. Therefore I am using an old weight-scale. The component wich includes 2 Strain Gauges has 2 seperated wires coming out and 1 other wire conected to the Ground. Because we can't find something changing when we measure differend kinds of things, (for example the changing resistor-value) we hope that you can help us. The two wires coming out of the Strain Gauges are connected to an Amplifier (TL081CP). The scale itself is a KRUPS TYP 841 ; 871-B Thanks!

Question by zupperzipper   |  last reply

### What gauge wire should I use for doing circuit board work?

Particularly the motorized window blinds controller.

### Can anyone make an instructable on building a gas welding gas kit?

Oxy acetylene kit with torch and gauges? Is it even possible?

Topic by eric m   |  last reply

### where to buy a R.P.M. gauge to read the total R.P.M. of my turbojet engine or how to make something this is a turbocharg

i need a device to read the R.P.M.s of my home made turbojet engine? what can i use (turbocharger) weel speed

Question by mirella1925   |  last reply

### MSA SCBA?

Where can i buy a used/new airhawk or firehawk MSA SCBA?

Question by m5industriesinc   |  last reply

### What components would be needed to build an ultrasonic thickness gauge to measure paint the thickness of paint coatings?

I need an ultrasonic thickness gauge, they work by sending a pulse through the material being measured (paint in this case). When the pulse strikes a denser material it returns to the sensor, the delay from the time of the pulse being sent to being received gives the depth. I anyone knows the components that would be needed, or ideally, a set of schematics could you be so kind as to help me out. Thank you.

Question by alkem   |  last reply

### how do I bridge a stereo car amplifier?

Http://www.drdetailshop.com/d2150.htm this source say that my amp is bridgeable and that it can run stereo and mono simultaniously. It is a 2 channel amp, however I only have one speaker.. I need both left and right channels running into the speaker. How can this be done? What would be the impeadance if the amp is running at 4ohms and the bridged subwoofer speaker is 4 ohms? what would be the overall wattage? how do i do this without causing damage toi my sub,amp, or radio? does this put excess strain and/or heat on the amp? if so how do I fix this? is there any wiring gauge problems that i should be concerned about? (18 gauge for input power, 18 gauge for speaker output, plan to lower the gauge of the speaker to somewhere around 12 or 14)

Question by fastcar123   |  last reply

### Moving the flash off the circuit board of a disposable camera. Gauge Question.

Got a project in mind but looking for some advice.  I want to reuse the innards of a few disposable cameras but I want to move the flash units off the board onto a separate frame to get the flashes closer together.  The brackets that hold the bulb to the board are metal blades but if I was to remove those and replace them with wire, what gauge should I start with? Thanks

Topic by wiredcur   |  last reply

What gauge wire do I use for my secondary coil

Question by wiccakingkamui   |  last reply

### The force of the coil without iron core Answered

Dear All..  If two coil A and B without iron core same as (size) dimension  and but coil A winding with 28 gauge and coil B with 32 gauge magnet wire Please help me to know : What is name coil more force for  attract a piece of ion metal. Many Thank you                                                                            Best regards                                                                                         lam

Question by lam   |  last reply

### What voltage can heat gauge 24 nichrome wire 30 cm long successfully? Am building a polythene sealing machine

Am building a polythene sealing machine using nichrome wire, I use 9v battery but is not heating. What voltage should I used and can I use ac or dc

Question by Gopep   |  last reply

### Fireworks Ignitor

I'm looking to make a bottle rocket igniter, and I am trying to fit it in the smallest package possible. If I were to use the circuitry from a stun gun, and connect it to some 16 gauge nichrome wire, could it heat up the wire enough to set off a firework? I could also use wire of a different gauge(32-40) if necessary.

Topic by H20

### what is the relation among them?

Hi my good friends want to ask a simple question i want to make an electric heater. what is relation between wire length and gauge of nichrome wire for use in heaters. how gauge and length of wire can effect the efficiency of heater output. is there any other wire that have more heating output than nichrome wire? thanks all and love u waiting for your kind replies.

Question by waqas12345   |  last reply

### Need help constructing a transformer!!!

Here are my specs and anticipations for my homemade transformer: Im looking for my transformer to produce a voltage of 400vAC out of a standard 115vAC wall socket. If ive done my math, and this is where I would like do correctig if noticed I need a turns ratio of 1.2 : 3.5. That is 1.2 to 3.5 or 115 turns of primary and 350 tunrs of secondary. 115 X 3.5 = 402.5vAC respectivley. I have access to a fero-core so thats not a problem. Im using 22-20 gauge wire for the primary and 18-16 gauge wire for the secondary. If you find my wires to be of incorrect gauge please let me know. I realise 18-16 is rather large for a coil but I was trying to keep safety in mind do to the high voltage.

Topic by darthDIY   |  last reply

### To change Magnet coil 240 volts ac to 120 volts ac Answered

Hi  All,,, I have a motor an aquarium air pump 240v ac 3 watts Supposing this motor winding with 3000 turns 32 gauge wire. Now I like to rewinding for 120vac.(3watts ) Please help me to know :  - Must  rewind 1500 turns with 32 gauge wire  or other way....                                                        Thank you in advance for your time and sorry my English not well.                                                                           Lam

Question by lam   |  last reply

### Citizen Science Contest Prize ?

I won a prize in the citizen scientest contest , I recieved my instructables prize pack but no sign of the rain gauge. Please help on this .

Question by Bot1398   |  last reply

### Could someone tell me exactly what resistors/DC transformer/gauge copper wire I need? Maybe even provide some links?

So I'm trying to make this:https://www.instructables.com/id/cool-DIY-infinite-LED-tunnel/ and I bought 20 of these Blue 10mm superbright LEDs 1025LB7C Could someone tell me exactly what resistors/DC transformer/gauge copper wire I need? Maybe even provide some links?Maybe even provide some links?

Question by shyguy567   |  last reply

### MOT confused?

Been watching a lot of videos on youtube about increasing the voltage on Microwave oven transformers!. what i cant undrstand is when people take out the secondry windings of the transformer & replace it with a few turns of 10 gauge wire to increase the power how does it work? as from  what i've seen the 10 gauge wire still has the insulstion on it so how does the current cant get through to produce extra power?. Also what do the shunts do in the workings of the transformer?. can anyone explain this to me in laymans terms!. Thank's, Tezza1.

Question by tezza1   |  last reply

### What is 3d wire? Answered

I have heard this term from an instructables member and I would like to know what gauge if any I can use to ground my tesla coil.

Question by nerd7473   |  last reply

### Current and voltage ratings in dc plugs and wires? Answered

I had this great idea to turn old cell phone chargers into DC extension cords.  Cell phone wires are nice because of their curly spring wires.    I worried the wire gauge might not be large enough to handle my project.  Here is my question.  On websites that list current ratings for standard wire gauges, they list current limits but not voltage limits. Why is this?  If a 22 gauge wire can handle .92 amps does it really not make a difference whether it is 1 volts or a million volts?  Why don't they use watts to list how much power a wire can handle.  Watts take both volts and amps into account. Another mystery is that my DC plugs are rated for 6-10 volts.  Why are the plugs rated for volts but not amps?  What would happen if I used these plugs for 4 volts, which I plan to do.   Thanks -Jacob

Question by Noblenutria   |  last reply

### Search coil anatomy?

I am in the process of making a metal detector and have come to the point of making the search coil. My question is about the contruction pattern, wire gauge, wraps, and housing material (mostly what not to use).

Question by Dauntless   |  last reply

### Voltage regulator?

I need to know how to build a 12v-5v pulse regulator for my fuel level sending unit/gauge in my truck. I would like to know what parts to buy and the order of everything. Thank you in advance. Daniel

Topic by gungfudan   |  last reply

### Where can I find 4 AWG wire? Answered

I got my microwave, and now I want to make a spot welder. Any recommendations for where to find 4 AWG wire, or something similar?

Question by CameronSS   |  last reply

### Schematic symbols?

I found this schematic in a 1947 manual on vacuum systems and I cant translate the indicated DPDT switch into something I understand. Can anyone sketch a quick pinout for it, preferably indicating what goes where on the schematic. This goes along with my other pirani gauge question.

Question by The Ideanator   |  last reply

### Would 3 camera flash caps make a strong enough bank for a coil gun?

I've got 2 capacitor banks right now. The first one uses 3 300V, 120uF capacitors, and the second uses 2 16V, 1000uF caps. Is either of these strong enough to make a coil gun that fires 2mm iron pellets at around 200fps? What if I give it a second stage? Also, I've already made 2 coils around plastic tubing, one using 3 layers of 16 gauge wire with 15 turns each, and the other with 5 layers of 20 gauge with 25 turns. Which one would give me the most power?

Question by AndrewJewer1

### Jule thief transformer issues. Answered

I'm trying to make a Jule thief, I set up the circuit and tested it using a salvaged transformer and it works fine the only problem is that the salvaged transformer is kinda large. So i decide to try to make a smaller transformer using a Radio Shack T4452-1R2L choke and 26 gauge magnet wire. i managed to fit 15 pairs of windings onto the T4452-1R2L Toroid, but when i tested it the led won't light up. I tested the wires for shorts using a multi-meter and even tipple checked that it was wired correctly. Is this Toroid just not suitable for use in transformers of this kind or do i need to use a smaller gauge wire or is there something I am overlooking?

Question by FrozenKnight   |  last reply

### I am looking for a sensor that measures "pressure" but I don't know what to look for.

I have an idea, nothing revolutionary, but it would perfectly solve a problem that I have in my woodworking shop. I need to be able to tighten a very small toothpick-sized piece of wood in a small meral vice, to a very specific level of "squeeze", and then release the vice, and repeat that exact "level of squeeze" over and over. Can someone point me in the right direction of what these "pressure measuring devices" might be called? Ideally I could use this pressure gauge (sensor) in tandem with a small display and an Arduino, Raspberry pie, or some other logic device that can interpret the output from the pressure sensor and send that output to the little display.Thanks for your help guys!

Question by Dolmetscher007   |  last reply

### How to wire a 12 v dc pump?

12 volt 16.5 amp dc pump to a 12 volt power source with a 20 amp fuse...battery on motorhome is 35 feet away.  Instructions for flojet motor say to use 10 gauge wire if more than 25 feet.

Question by ruawake   |  last reply

### Simple electrical insulation question. Answered

If I have a 10AWG insulated solid copper wire and the THHN insulation is rated for 600V, should I worry about a 5000V 60ma current arcing straight through the insulation if its coiled in a helical form?

Question by imMrDude   |  last reply

### Reuse old motor from cement mixer for building coils in the axial flux alternator for diy project 1kw wind turbine? TIA

The coils in the alternator are meant to be 14 gauge enameled wire, does anyboedy know if the wire in other ac motors like the one in a cement mixer use this type of wire? Cheers!

Question by llucop   |  last reply

### How to synchronize the brightness of a grille-mounted neon tube/LED bar to a car's tach/speedo?

I have a 1997 BMW 328i, and I've been thinking about installing either a neon tube or a bar of LED's in the grille of the car to use at night (most likely not street legal, I know). I want the brightness of the tube/bar to be controlled by one of two things: The speedometer or the tachometer. I.e., if the speedometer is at 0 MPH, the light is off, and if the speedo is at 75 MPH, the light is fully on. Same thing with the tach, light off at 0 RPM, light fully on at redline. Unfortunately, I haven't the slightest idea how to use the car's computer or the gauges themselves to set up a control module for the light. If any of you has a good amount of knowledge about automotive gauges, I would appreciate your help!

Question by Jonny Katana   |  last reply

### Does it matter how a coil is wound? Answered

Hi everyone, Take a look at the illustration attached.  Is there any real difference in values between the four winding types? *** Assuming same core, same wire gauge and same number of windings on all 4 primaries, and all 4 secondaries *** A) Both primary and secondary are wound TOGETHER. B) primary is wound first, then secondary wound ON TOP. C) Primary and secondary are wound at OPPOSITE SIDES of the core . D) Primary and secondary are wound next to each other on the SAME SIDE of the core. Note that figure in D it seems like the wires are thinner, but I assure you, that's an optical illusion, and the gauge is the same in all 4 figures :-p Again, the question is whether the 4 coils would act the same in a circuit, or is there a difference in values between them? Thanks!

Question by Morgantao   |  last reply

### HOME LED POT LIGHT WIRING?

Is it better to run 120v wiring to each pot, or run 2 wire 18 gauge cable to a central box. LED's are 12v 3w dimable. I would like to dim from 2 to 10 pots per switch. Where would I put the transformer. Could you suggest a  wiring diagram.

Question by NEIDO   |  last reply

### 12v dc nichrome electric heater

Hi friends i want to make electric heater that could give sufficient heat with 12 volt dc battery. how much nichrome wire in lenght should i use and how much gauge of nichrome wire should i use. i love for your kind replies. love u all

Question by waqas12345   |  last reply

### Small Voltage Regulator

I am looking to buy or build a small voltage regulator that can fit in an O gauge electric train engine. It needs to have a 18-20 volt AC input and 10-12 Volt AC 1 amp output. I would like to buy one already built, buy a schematic or a schematic with the parts to build. Thank You

Topic by frankv6   |  last reply

### Electromagnetic coil design, effect of wire AWG and turns.

I made coil of core length 28 mm and wire gauge 38 and 1850 turns but i am getting very less magnetic compare to other coil of core length 21mm, 28 AWG and 1000 turns. Could you please sujjest what might me the problem. And current we are giving is up to 0.5 A.

Question by ಗುರುತ   |  last reply

### How can I measure pressures/strain up to 5000kgf? Answered

I desire a device to measure a weight up to 5000kg. I don't know if this is termed a strain gauge or a pressure plate. my requirement is that the pressure plate itself be at least as small as a washer for a 10mm bolt. I need the device to record the maximum force, as the force is variable over time.

Question by Phil11   |  last reply

### need info regarding replacement items in circuit.....

Hi guysI am trying to build a three stage fm transmitter and for the life of me I cannot find a 5-20p trimmer cap anywhere as well as the copper tinned coils...what can I replace the trim cap with.....a cap with a different value? and what can I replace the copper tinned coils with....normal 18 gauge wire coil?..any help will be welcomed

Question by JJK6   |  last reply

### Coil gun doesn't work help?

I used about 5 ft of 22-24 gauge insulated(thin) wire(single strand)and coiled it into about 1 inch long coil, the power is about 170VDC , when I test it out nothing happens, My ground is soldered together and I test it by connecting the positive to the other end of the coil, there is a spark but no projectile i try moves at all.

Question by tom10122