Low Voltage Disconnect?

Hi, I would just like to seek your assistance and idea for the observation below on my experiment: I have a gadget that is being charge by a 2w 9v solar panel, the problem is I haven't place a blocking diode and I observed that when I tested the charging slot there is about 0.16v output. To clear it that was supposed to be my input voltage. 1. Question is why does it produce an output voltage even though it is imy input voltage? 2. Would the 0.16volts output have a significant effect on my system during night time and or bad weather? Please give facts and computation if possible. 3. If I want to step down my input voltage of 9volts to 4.5 volts can you give me the idea how to do it. Well, I am asking you this because your insights and helps for me in the past are very helpful for my science project. Thank you teachers

Asked by mitchiko 7 years ago


I am making an inverter whivh converts 12 V dc to 230 V ac i am using 2 33 ohm resistor of 1 watt to connect the load on transformer whenever i switch on the ckt the 1 watt resistor are heating to much and multimeter does not show any voltage i am using 12 Volt dc 2.5AH battery as power supply what is the problem

Posted by AbhishekR2 3 years ago

Do you know low carbon living ?

As the subject saying, do you know what is low carbon living ?

Posted by bella2009111 8 years ago

Problem with low battery indicator

Hi guys, I have built a low battery indicator circuit for a 6V battery source. It will light up a led when the voltage reaches below 5V. The 6V battery source powers a servo motor, which is controlled by a microcontroller. The problem I have is that when the servo motor rotates, the led lights up. And when the servo stops rotating, the led goes off. This happens even when the battery is above 5V. Any idea what is wrong? And how I could rectify the problem? I have attached the circuit of the low battery indicator, if it helps.

Posted by kurtselva 5 years ago

I'd like to build a 3rd order low pass filter, cutoff ~40mhz, impedence at 28mhz of 50Ohms?

Hello All. I want to build a 3rd order low pass filter with a cutoff ~40mhz. I'd like to build this in a metal box seperated into two compartments with a pi filter in each. What components do I need? The input output impedence should be ~50 ohms at 28mhz. It stray capacitence a problem? Thanks?

Asked by microcal 9 years ago

BLE on a chip to smartphone connection?

I'm trying to use the BLE option on my chip to talk to my smartphone. Any ideas or suggestions on how to go about this? Thanks!

Asked by maddywantstocode 3 years ago

help needed


Posted by carl1234 8 years ago

Anyone have any high-quality machining techniques that can be used in a low-tech situation? Answered

I want to make a CNC machine but I don't have the tools or access to tools that I'd like to make one,  all I have is a simple drill press, a little stand-alone vice that I can use on it, calipers, and micrometers. What I want to know is how can I, limited tools only (I hope), precisely drill (and possibly tap, I do have a tap set) a bunch of holes in aluminium angle/channel, acrylic, and MDF?

Asked by The Ideanator 7 years ago


I'm looking for a gaget that will allow me too read book titles of prices on low shelves without crawling on all fours. Hey, I'm 74. I look rediculous in libraries and find it hard to get up. Some sort of a periscope might work, or a traveling low chair to scoot along on and handle to help get up.

Posted by Nina Holland 10 years ago

Favorite Low Carb Recipes?

My other half and I have recently come to the conclusion: you can only eat so much talapia. We need help. He's a type one diabetic (the kind you get when you're a kid and some nasty virus destroys your poor pancreas) so that means limited carbs, and preferably the good kind of carbs (fruits, whole grains, etc). I've tried looking up recipes online only to find several very fancy, very expensive low carb dishes. Please help. We are college students who cannot turn to Ramen for this solution! Cheers and many thanks to you, Heather

Posted by mooseinakilt 7 years ago

Running LED on 1.2V rail

I have a board I am working on, and 3 voltages i'm working with: 3.3V, 2.5V, 1.2V. I want to have "Power OK" LEDs for each voltage rail. A look on digikey shows me that 3.3V and 2.5V wont be a problem, but there are no LEDs with a voltage drop less than 1.2V... and if there is, theyre probably expensive. So what is a simple way to have a "Power OK" led for 1.2V rail? p.s. I'm using all 0603/surface mount stuff.

Posted by samurai1200 8 years ago

help with changing transformer output of 8.5VAC 1200mA to 9VDC 1000Ma.

Howdy folk,    The Problem; I need some experienced assistance with changing the output of a transformer from 8.5VAC @1200ma to 9VDC @1000ma. Thanks in advance for any & all assistance.    The Back Story; The left channel went out in my PC speakers, which is designed for 230VAC, I had to destroy the woofer case to get to the transformer, and discovered that it outputs 8.5VAC @1200ma. I have another set of PC speakers (different manufacturer) that takes US voltage (110v) and steps it down to 9VAC @1000ma. I must first plug that transformer into a 100watt 230>110 step down (because I'm currently in the Philippines) and I want to get at least one transformer out of the "equation". I would just buy another system set up for local voltage, but I'm on a fixed income (until I can return to the States) that prohibits this avenue. I CAN afford some small components, but that's about it. Thanks again for any help. -Z-

Posted by Zclip 3 years ago

Ultra low voltage buck converter

I want to step down voltage from a 1.2/1.5v battery to 0.05V. Any advice?

Posted by huzefa 8 years ago

How to make a solar-powered garden fountain low maintenance by adding a float valve? Answered

I have a solar-powered garden fountain that I wish to make very low maintenance and not have to manually fill with water. How could I install a float valve setup in the fountain? Has anyone ever done this? Any ideas?

Asked by arnold54 9 years ago

can anyone help me design a transformer for low voltages?

Can anyone help me design a step-up transformer where the input voltage is around 100 mV (AC) and to be converted around 2.5V (AC)?

Asked by jeromekang 7 years ago

How do i build a super cooler? Answered

Hello.    I am looking for ways to turn cool down oxygen to -253C.    Can i do this using house hold materials (Maybe, building a refrigerator that can reach extremely low temperatures)?    How do i do this?

Asked by jamesc4 5 years ago

Help! My low voltage, outdoor lighting wont light up - transformer error codes?

I bought a Portfolio 300watt transformer for low voltage outdoor lighting and hooked up a 100' 12 gauge cable (outdoor rated lighting cable) to it. Then I hooked up 4 low voltage lights (12volt 20 watts each). I plugged the transformer in to a gfi outlet that I ran out from the house. And turned it on. The little display flashes "E" and then "1" . The instructions say that the E means that there is a fire hazard so check the circut. So I unhooked every light except one. Same error. I hooked on a different light and unhooked the first one. Same error. Instructions say the cable needs to be under 250'. And the load less than 300w. I am there, except it won't run. Do I have a bad transformer or is there something that I am missing? Oh, and this is to light my haunt in my front yard, so I am running out of time! Thanks for any advice! Matt

Posted by mckeephoto 8 years ago


My old LG flip phone still has lots o' pics, contact info, etc. I don't wanna throw it out, but the battery no longer holds a charge. I'd like to recycle the old battery, but when plugged into a charger with no batt, the phone  will not turn on.   Why can't I power it up on the wal-wart transformer alone?  Do I really need to spend $40 on a battery just to access old pics n stuff? Is there some proprietary circuit in there that "says" to the phone "I'm here"  other than just plain old voltage? Although the old battery seems to work just well enough to access data as long as it's plugged in, I'd like to get rid of said battery in case it eventually leaks.

Posted by Toga_Dan 4 years ago

wind turbine speed?

i have herd that the minimum amount of wind required to power a (homemade) wind turbine is 10 m.p.h. is that true? and whats the maximum wind speed?

Posted by Sun Gear 7 years ago

Wanted: 9 volt light sensor module

Calling all you that know and enjoy making circuits. Here is my problem.  This is too bulky of a solution with a relay switch and 12v battery pack. https://www.instructables.com/id/DC-Low-Voltage-LIght-Sensor-Switch/ What I would like is a 9 volt input and 9 volt output.  Actually, whatever the input should equal output.  So if I connect 3 v battery, I want 3 v output.  Right now I need 9 volt in = 9 volt out.  No Relays!!!  Simple and clean circuit board only. The LED can't be soldered to the board.  I need the capability of extending from the board with wire to adapt to my needed projects. On another note, if you know of something already on the market, please send a link.  I will be happy to make the purchase. OH... no modules that need a microcontroller.  Need a stand alone module. Thanks! Looking forward to hearing back soon. The Water Dog

Posted by DiyWaterDog 1 year ago

PVC pipe at low temperatures

I have a question for spudgunners and other people who know about PVC. I've heard that PVC becomes bitter at low temperatures, so you shouldn't expose your spudgun to low temperature, but is it okay to leave it out in the cold and then warm it back up for use later? Does that affect the strength of the PVC? I have a problem storing some PVC in an heated environment during the winter.

Posted by starwing123 9 years ago

Charging capacitors with different currents? Answered

How does charging a big capacitor with a high current affect it rather than a low current? Certainly time taken decreased. What are other effects, and is it as safe as using a low current?

Asked by ARJOON 6 years ago

Low voltage health problems

Hello, I saw a great project on youtube, a water button, and gave it a try. it works, all it does is when one touches water, a led turns on, just a proof of concept. But what I was worried about, is if there are any negative health impacts of 3.3 v going though you and into the ground? The power is not noticeable, but still, I worry. ps. I did Google this, but couldn't find anything.

Posted by penguins 9 years ago

how to construct a low voltage protection system using annunciator?

Hi in our college for our first year mini project , we were given a problem statement and based on it we have to find a solution , but i am not able to ,so here is the problem statement "low voltage protection system using annunciator generate 5volt power supply from 230volt ac and activate beeper when power supply is below 180volt.choose components with appropriate materials.list the important property based on which the material is chosen for the components .draw the waveforms of current and voltage at specific branches and node.find the laplace transformations ." so if any one  does come across some ideas please help i have my first review coming by so reply ASAP guys

Asked by archanapurvi 5 years ago

shelf couch

I have a fairly barren room with two windows on one wall, and I would like to make a low bookshelf underneath the windows that will also be wide enough for a pseudo-couch to lie down on for reading and other relaxing activities. I took more time making the paint drawing below than this post, so APPRECIATE! Thanks 8D

Posted by Schisler7 9 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 9 years ago

Variable, low-RPM DC motor setup?

Hey guys, I'm hoping to build a motorized slider system for my DSLR camera. I'm going to build the slide from scratch and probably attach a motor with a pulley system to move the slide, this should give me the option of having the camera climb the slide if it's on a slight angle. I'm not extremely electronically inclined but I understand I will need a low RPM motor and a PWM unit to adjust the speed. I'm thinking RPM between 0.5 & 10 would be ideal. Could I buy one of these (http://www.aliexpress.com/item/12v-100w-pwm-speed-controller-motor-governor-DC6-15v-STP50n05-wholesale/1663330358.html) add a 12v battery and a 12v DC motor and call it a day? If this is the case, should I be aiming for a 10 RPM motor that I can turn the speed down on? Is a 12v battery/motor likely to give me reasonable torque for dragging a DSLR camera up a moderate incline? Battery life shouldn't be an issue as the longer the use the less RPM I'll need. Any thoughts would be much appreciated.

Asked by tig5 4 years ago

low voltage photoelectric switch for led spotlight

I need help. I am making an led spotlight to mount on the flagpole and light up the flag at night. I have the lights from a 46 led flashlight. I've attached 2- 3.7v Li rechargeable batteries and a solar cell charger. Everything works great, except I want a photoelectric switch to turn light on and off. Right now, it is on a manual switch mounted to the pole. I cannot find and don't know how to build a 3.7v photocell circuit. I've tried 12v (all I can find except for 120v) and they won't work. I need to know what I need to make a 3.7v circuit/switch, and how to tie it in to the existing system. Can anyone help me? Thanks for any input. I am a novice, so be gentle. BJ

Posted by cottnpickr 9 years ago

K155ID1 chip showing low voltage between decimal pins and power supply. Is the chip bad? Answered

Hello, I turn to those who know probably a heck of a lot more about this than I do.  I've been trying to build myself a nixie tube clock, and everything has been going fairly well. I recently got the driver chips in the mail which convert BCD -> Decimal in order to hook the nixies up to a digital logic system like an arduino. I'm using a 12 V -> 180 V switching power supply for lighting the nixie tube. It is connected to ground on a computer power supply that I'm using to power the entire project. The 5 V rail on the computer power supply is connected to the Vcc pin of the K155ID1 chip as shown in the picture. I've connected the ground pin on the K155ID1 to the common ground of the computer power supply. I have nothing connected to the A, B, C, or D pins on the driver chip, which from what I understand should be the same as inputting the BCD number 0000 or just 0 in decimal. If I'm inputting a 0 as my number, the chip should output a 0 in decimal. From every single datasheet I've seen talking about this chip, that should mean that pin "0" (as shown in the picture) should become effectively grounded, and assuming that the "0" pin is connected to the 0 digit on the nixie tube, that should connect the nixie tube to ground, which should allow 180 volts to flow through the nixie tube, causing it to light up. Unfortunately, this is not what happens. In fact, nothing happens. Nothing happens no matter what pin on the driver the nixie tube is connected to. The only way I can get the nixie tube to light is if I connect it directly to ground, in which case, it lights up very nicely, but obviously that doesn't help with controlling it in any way. I took out my multimeter and measured the voltage between the 180 V supply line of the nixie tube and the pins of the driver chip, and every single pin (except A, B, C, and D) show a voltage of about 80 volts, which is not enough to light a nixie.  My question is, is there something I'm missing? I would think that the chip was bad or that I popped it or something. Heck, you could fill an electronics graveyard with all the chips I've popped over the years. But I've rebuilt this setup 4 times now, and I've attempted this following multiple schematics, and even switching the chip out for a brand new one 5 times. Each and every time the result is exactly the same. Either I'm overlooking something huge, or I just happened to buy 10 dead nixie driver chips. Thanks, in advance for any input!

Asked by tylervitale 2 years ago

Windows XP Running with as little as 18MB or RAM

I managed to run Windows XP (stable) with as little as 18MB of RAM, Originally for my PSP to run.With Dosbox i can Allocate up to 16 MB of RAM, with a little tweaking i could get it to reach 18MB.But XP Can't run in DOSbox, But it Can Run in Bochs, It may be slow but hey, If i can Run Windows XP on my psp, It is still an accomplishment.Here are some screenshots of it Running is QEMU, On a PCSo what do you think, I am planning to port QEMU to the PSP so we can finally make this a reality, BOCHS only works in 1.50 Firmware, and i don't see a psp Slim with 1.50 and my PSP is a Slim and ...well you know.Well ThanksBe sure to comment(and rate, Just because it is neat seeing topics with a rating...) And tell me what you think!~ReCreateEdit: Now i uploaded a video!(or i am uploading a video...i have to remake it due to the stupid 10MB limit)

Posted by ReCreate 8 years ago

Simple, efficient, low-cost, solar energy equipment

I am looking for a DIY simple, low-cost solar water heater and solar light that will work in any kind of weather and still be able to supply atleast some working heat and light. Please suggest.

Posted by rseni 9 years ago

Is there a difference between a high pass filter with an op amp and a high pass filter without one? Answered

I'm trying to modify a guitar effects pedal of mine to remove some squeaking and decided that a highpass/low pass combo with some potentiometers to modify the highpass and low pass points (since my pedal emits squeaking at different frequencies on different settings) and I was wondering if I should use a high/low pass with an op amp, capacitors, and resistors - or just a simple resistor and capacitor filter. Does anyone know if either configuration is a detriment to sound quality?

Asked by Squag 6 years ago

Does any one know where to get cheap bundles of knex pieces online? Answered

Preferable alot of pieces and new if possible? I have tried ebay but its all used and the box sets are to expensive. Any other sites i can find knex for low prices?

Asked by K-Dawg 9 years ago

i was reading a post lastnight about an led light that used dead or low batterys. I can not find it today

I thing that there were 20 or moer leds in the project. It won a contest of some type. can you tell me where I can f ind that instructable? It was a well writen site with pdf disign downloads

Asked by jrags 8 years ago

Voltage controlled low pass filter with resonance schematics, anyone? Answered

Can anyone provide a link or schematic for an audio low-pass filter with resonance, with the low pass frequency able to be controlled with varying voltage? I'm hoping to make something like the moogerfooger, but I don't need an envelope filter.

Asked by aelias36 6 years ago

Where can i get a self priming pump for a low cost?

I've looked through ebay but they're way too much money. any good RELIABLE places you guys know of. My price limit is probably around 150 USD

Asked by Ha4xor4life 8 years ago

how to make a 8 bit picture?

well i am in some need of 8 bit pictures and i dont know how to make them out of higher quality pictures any program that can do this and hopefully free

Asked by knexsuperbuilderfreak 7 years ago

how to find the right used car for me? Answered

All right  guys and gals i need to find a good used car in the atlanta area but am having the hardest time doing so if any one knows on a good reliable honest search engine ect. for used cars within a certian make modle and budget please let me know. thankyou, fidgety

Asked by fidgety2 7 years ago

Would a glass, vacuum-insulated thermos be able to withstand the extreme cold of liquid-air?

I am in the middle of designing a system to produce liquid air using the von linde process. the termos would not be under any pressure, but it will get quite cold. can a thermos using a glass vacuum insulated inside be able to withstand temperatures below -180 degrees celsius?

Posted by pedrogabman 8 years ago

Can a glass, vacuum insulated container withstand temperatures in the -180 degree celsius range?

Is it possible to store liquid nitrogen and oxygen in a vacuum insulated container for a short period of time? i have a thermos that i though might work, but i want to be sure that im not going to have the thermos explode in my face when i try it. this is an old beefy thermos that can take at least 190 degrees celsius, but im not sure about the other direction.  

Posted by pedrogabman 8 years ago

Any good software to image A drive?

I need to: Low level, Image a 3GB drive with BeOS installed on it, with, Of course, BeFS. Some programs don't work, as the unknown filesystem does not register a drive in windows, and they seem to be too high level. I want to completely image a drive, connected to my laptop via a USB HDD reading thingy, The boot sector, all the files, and everything. Any suggestions to good(free) software that can easily low level image a drive? Thanks ~ReCreate

Asked by ReCreate 8 years ago

Really Mini Shocker?

Hi all, I am looking to build a really miniature, low-output shocker device and I've come a bit stuck. The instructables that I have see here all seem to dispense shocks of about 400v and I think they are too painful for what I have in mind, though I don't really know (if you know better then please tell me, you may make my life easier :) ). I'm looking for the device to be able to deliver no more than a distinct nip, and be about the size of a Cr2032 cell. I also would like a miniaturised power source like that. Can anyone tell me if this is possible and point me in the right direction as to parts and where to get them (I'd like to salvage as many parts as possible because I'm on a tight budget). Thanks in advance to all who reply.

Asked by BlondGuy101 8 years ago

Recent is using low number of years again.

Recent is using low number of years again in Answers... Again

Posted by iceng 2 years ago

Quality servos for an low price? Answered

Where can i get good quality servos for an low price?

Asked by MACKattacksnipe 8 years ago

Low Voltage Higher Current?

I am having a strange problem on a USB peripheral.... it is a digital radiography sensor that overheats. I believe it may be due to the power supply to the motherboard, but I don't know for sure. I am ASKING FOR YOUR HELP in reasoning out what may be the cause. Anyone with computer/electronics experience, PLEASE HELP!!! I was told that my power supply is too low voltage, and that current is going up in the USB peripheral causing it to heat up. I always thought V=IR means that if voltage drops so does current. But in other places I read that if voltage drops, current goes up so that the wattage/power usage stays the same according to P=VI. So which is it? V=IR or P=VI ? If my power supply has too low voltage, will the current in the device increase to compensate? Or will it just have a lower current? Does it depend on the circuit and the exact electronics in the USB peripheral? Here is my SETUP. It is SIMPLE: Antec AR-350 power supply connected to a motherboard Asus P5N7A-VM in an ATX case. All I have otherwise is a SATA hard drive and a SATA DVD-ROM in there. That's it! Problem started to happen about 1.5 years after I got the computer. That is why I am thinking maybe it is the power supply, or maybe it is the motherboard?  The computer works fine in every other way! It uses Windows XP and has a wireless keyboard/mouse which also works fine. BIOS settings screen Hardware Monitor shows voltage for USB 5v reading about 4.9v, within tolerance. However, one of my USB peripherals is a digital xray sensor. It works ok a few times, then it starts to overheat and fail. This only happens on this computer. When I use another computer (like a laptop) with the same USB hardware it functions ok and never overheats. I don't have any problems on the other computer, even thought I am using the same software/drivers. I bought a different ATX case with a new power supply, and just moved the motherboard, HD and DVD over. Now the motherboard BIOS shows under Hardware Monitor that it is getting 5.2 V instead of 5v, so it is higher! Also the 12 V is higher (around 12.2v) and same for the 3.3V. All the voltages are HIGHER! So I have yet to test this new configuration with the USB peripheral sensor.  Could the motherboard be faulty? I did notice the motherboard looks "curved" with the area under the CPU sort of bulging out. However, with this motherboard you will see there is a huge heat-sink/fan that gets clamped over the CPU and that may be bending the board. Keep in mind the board works perfectly otherwise, so I am wondering WHY it would only affect USB for this one peripheral and not for the keyboard and mouse? Maybe the circuitry on the keyboard/mouse is more tolerant to low voltage? Would appreciate your thoughts please.

Posted by edy 6 years ago

What is the difference between expired and new film? Answered

I am looking to buy film for my new Polaroid cheaply and have found expired film to be much less costly. However, is it risky taking photos with expired film? Will they come out differently or not even develop at all? Does the date it expired matter?

Asked by likls 7 years ago

Low cost water heater

I wish to build a simple, afordable, low cost, solar water heater that is easy to construct and does not need electricity. Is that possible?

Asked by rseni 9 years ago

Arduino starts up automatically

Hello instructables, i ran the code below in the arduino uno, (4 motors, 2 L293D driver chips) void loop() {   digitalWrite(motor_pin1,LOW);    //forward back   digitalWrite(motor_pin2,HIGH);   digitalWrite(motor_pin3,HIGH);      digitalWrite(motor_pin4,LOW);   digitalWrite(motor_pin5,LOW);    //forward front   digitalWrite(motor_pin6,HIGH);   digitalWrite(motor_pin7,HIGH);      digitalWrite(motor_pin8,LOW);   delay (5000);     digitalWrite(motor_pin1,HIGH);   //turn right    digitalWrite(motor_pin2,LOW);   digitalWrite(motor_pin3,HIGH);     digitalWrite(motor_pin4,LOW);   digitalWrite(motor_pin5,HIGH);   //turn right    digitalWrite(motor_pin6,LOW);   digitalWrite(motor_pin7,HIGH);     digitalWrite(motor_pin8,LOW);   delay (2000);     digitalWrite(motor_pin1,LOW);    //stop moving   digitalWrite(motor_pin2,LOW);   digitalWrite(motor_pin3,LOW);      digitalWrite(motor_pin4,LOW);   digitalWrite(motor_pin5,LOW);    //stop moving   digitalWrite(motor_pin6,LOW);   digitalWrite(motor_pin7,LOW);      digitalWrite(motor_pin8,LOW);     while (1); } by right, the motors should stop infinitely due to the while(1), but this is what happens instead : initial                 : loop1 12 secs later   : loop 2 1 sec later        : loop 3 1 sec later        : loop 4 .... why is it running more than once?

Posted by fujiapple 6 years ago