Search for 555 timer in Topics


555 timer

I need help to understand how a 555 timer works, but mostly how I could build one. or if some ones willing to make one for me, i'll buy it, but it needs to have a ways to control it. well talk if your interested. I need it for a gate control for my SCR induction furnes.

Topic by Danielro10    |  last reply


555 timers?

I was wondering if there is a difference between a ne555p timer chip and a ne555d timer chip, and if there is then what is it? if there is a difference between them, then where can i buy a ne555p timer in australia? :)

Question by jcolefran    |  last reply


555 oscillator?

How can I make a simple variable oscillator out of a 555 timer, loudspeaker, capacitors, transistor, potentiometer, and resistors? (and anything else I may need). I would ideally like it to go from about 10Hz-20KHz.

Topic by andy70707    |  last reply


555 timer cicuit

Hello guys I have a minor problem, I built a 555 timer circuit and it runs off of 6v. My plan is to use a 9v battery. Will the project be OK or will I need to drop the voltage and how would I go about that? Would I connect a resistor to the positive of the battery then to my project's input? Thanks, 

Topic by HavocRC    |  last reply


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.

Topic by qwertyboy    |  last reply


Running a 555 timer? Answered

So, I have this program that I got online that simulates a 555-timer. Basically, if you want it to put out X Hz in Astable mode, it'll tell you which capacitors to use and stuff. It'll also show you how you can modify the duty cycle.  I'm wondering if anyone can explain something to me: When I run the program in astable mode, the duty cycle must be above 50%. I want to power an LED that flashes very briefly, but has a relatively large interval of being off until if flashes again. Something more along the lines of a duty cycle of maybe 5%-20%.  First, could you explain why the program constrains the value like this? Is it because the 555 can't run at a duty cycle that isn't greater than 50%? If that is the case, why can't it? Second, if I can't run it like that, what would you propose I do to power the LED in the manner I described? btw, if you want the program follow this link: http://clarkson-uk.com/555-timer/ It's actually a pretty cool program! :D

Question by tylervitale    |  last reply


555 Timer Projects

Help me find projects using a 555 timer as many as possible. The hreater the better

Topic by e=mc^2    |  last reply


555 timer help

Lets say I have one 555 timer and I wanted to have two LEDs blink at a different time each three seconds apart like this LED #1 Blink...1...2...3 LED #2 blink...1...2...3 LED #1 blink... how would I do that or is it even possible.

Topic by iman    |  last reply


555 monostable timer

I've no idea what I'm talking about here but can only explain what im looking for which is help. I'm basically looking for a relay or multifunction relay not really sure but here's the plan. When my smart plug is turned on (at certain programmed times through the smart plug app) to provide power to a 12v 6amp pump (I have 240v ac to 12v DC transformer pluged into smart plug I'm in uk) I would like for this pump to turn itself back off after 10 or 15 seconds. I cannot for the life of me find an analogue or digital timer that can do seconds. The smart plug can work down to minutes and not seconds. So basically smart plug on = pump run for 15 seconds cuts itself off and then the smart plug turns off once the minute is up and when plug is on again at next programmed interval it does same thing. Any help would be great as I've no idea what I can buy or try to make thanks When trying to research I hear about 555 monostable circuit but I don't know how to wire something up or what to buy to make this work.

Topic by croyf85    |  last reply


555 monostable sensitivity?

Has anyone built a 555 monostable circuit that was extremely sensitive for no apparent reason? I'm trying to use one in a rube-goldburg machine, and for some reason it's extremely sensitive to any sort of touch! The circuit sometimes comes on for no apparent reason, other times it will stay on for longer than the expected duration after the button is pushed. I'm using non-CMOS 555 on about 5 volts to run a small LED. The capacitor I used was a 0.01 uF on pin 1 to 5, and a 1 uF electrolytic on pin 1 to 6. I used a 1M resistor on pin 7 to 8.  I'm simply baffled by it. I've tried using different breadboards, different PSUs, brand new components, and correct gauge wire, but despite everything being seemingly fine, it's still shows the sensitivity. Anyone have any advice?

Question by tylervitale    |  last reply



I'm trying to use a 555 timer to flash a LED but I want to be able to adjust the speed of the flashing Answered

I'm trying to build a simple circuit using a 555 timer chip Ideally a low power one so I can power it off 2 AAs to flash a LED at a variable speed from rapid flashing to once every few seconds. any help would be appreciated.

Question by joeAMERICA    |  last reply


I want to use a 555 timer to be off for 1 minute, give a brief pulse (about 0.5 seconds).

The circuit is to provide a pulse to a 4017B decade counter to count up to 5 minutes

Question by ralph4ed    |  last reply


panic alarm data?

 i request to get data about panic alarm.

Question by nelson ndegwa    |  last reply


Hey Guys,I need some help making a project for school

It needs to have at least 1 555 Timer within it. I was thinking of building a jacobs ladder with a 555 timer or if i could get it working perhaps a sonic pulse generator. Want something interesting and that won't take more then 7 weeks to build. Would it be possible to make a Cree Light and mod it to turn off after X amount of time? I'm just struggling to find idea's as our projects must be able to run off a 12V Battery or less and we cannot make anything dangerous. IE Rocket Launch Controller etc.... Thanks

Question by bcurko    |  last reply


555 timer circuit question

Hi everybody! I need to make a small pcb which will be able to turn on/off a switch about 10/sec, whenever I turn it on. I understand that 555 timer is the easiest way to go.Even better it would be if it was fully customizable like I could set it to open/close the other circuit from 1 to10 times/sec per manual switch on and also set the duration that the 555 will be keeping the other circuit on each time . I am able to do the soldering needed but I don't know the parts needed and how to properly connect the the pcb.Thanks (sorry for my poor English)

Question by c_fish    |  last reply


555 timer and servo help? Answered

Hello, I just finished building this instructable: https://www.instructables.com/id/The-Most-Useless-Machine/step6/Original-Design-Using-555-Timer/ However, I have run into a couple of problems with the 555 timer and the servo. As suggested by someone in the comments section of that instructable, when the server turns on it is consuming enough current to drop the voltage enough to mess with the 555 timer's PWM output (I do not have an oscilloscope, so I can't really prove this). Whenever the servo starts, it works properly for a couple of seconds, then it starts acting very strange, stuttering, going the wrong direction, ect... I'm thinking if I add a capacitor the the power source, it will help stabilize the voltage, but i'm not sure if this will work. Any help and/or suggestions would be greatly appreciated. Circuit is running at 6v (4AA cells) Servo runs at minimum 4.8v to max 7.2v

Question by psp3601    |  last reply


555 TImer/Chip Help

I need your help people of Insturctables. I am working on an project, and I need to make a circuit whit a 555 timer/chip so that it makes,for example, an LED light up in every 2 second. I mean when it turns on, it needs to be on for 2seconds than off for 2 second...loop. ON(2 seconds)___OFF(2 seconds)___ON(2 seconds)___OFF(2 seconds)___LOOP I need the output to be 12V. Actually I need it for a fan to turn on and off(the fan runs on 12 volts) Can you help me make a circuit for this, what value of the resistors and capacitors do I need... It would be grate if some one could make a schematic of the circuit in Eagle, or so... If I make an Instructables about my project I will surely mention who helped me realize my idea! Thank you all! -Stanislav

Topic by comodore    |  last reply


Switch a relay with a 555 timer?

I have a clap activated relay which I want to use to switch on my computer but when you leave the switch on my PC in the "on" position it just keeps rebooting. Would it be possible to use the relay to activate a 555 timer circuit or similar to the switch off the relay after 2 or 3 seconds?

Question by cheesemarathon    |  last reply


555 timer output hight and low? Answered

I just soldered up a 555 monostable circuit following an internet tutorial and for some reason the output seems to be both low and high. it can power a LED connected to the 0V & pin 3 and the 9V & pin 3. any ideas what might have happened?

Question by DrVonTrap    |  last reply



555 Am Transmitter Circuit Diagrams?

I have two ICM7555 CMOS 555 timers, and I was wondering if anyone has any good am radio transmitter circuits that incorporate two (or one!) 555 timers.?

Question by BurningSandman    |  last reply


Why is my 555 timer metronome circuit so variable?

I constructed this metronome circuit using a IC555 timer chip (see image below) and it worked fine on the breadboard. I wanted 2 ticks a second (2Hz) so used a trimpot to set that but was getting wild fluctuations with either the tempo increasing or really fast ticks even with the trimpot at maximum resistance. So I changed out the trimpot to a 30KR resistor and that seemed to work, but after doing the circuit nine times, it has also proved highly variable and I don't know why. I'm running the circuit on 6V (2x CR2032) and my resistors are rated at 1% tolerance. Any help please?

Question by chiok    |  last reply


Creating a 10-15 second timer?

Hi All, Here's what I need to try and achieve: - I have a servo that I had modified and have removed the circuit board.  Now it just runs from 3 v - I want to reverse the servo once a momentary switch has been activated for 10-15 seconds - once time is up the servo reverses again I thought about using a 555 monostable circuit which would give me the amount of time, but I am unsure how to achieve everything above. I'd love not to have to use an arduino if possible. Any ideas? Thanks.

Question by lonesoulsurfer    |  last reply


How to make a timed LED

Hello I need help. So I want to make like a bomb timer where there is a count down and then it triggers something. It doesn't have to have a display of the numbers just like I can set it for however many seconds, then push a button.  Thanks

Topic by HavocRC    |  last reply


Can I use a 555 timer to cycle on 1 minute and off 1 minute? Answered

I am kinda familiar with the 555 timer for flashing lights and such, but I am in need of a circuit which will cycle on for 1 min and off for 1 min. Can this device (555 timer) be used for such low frequencies. It will ultimately control a 12v relay to run a bilge pump in an Instructables evaporative cooler which I am making (this mod is my idea which I will share with the original inventor if it works). I guess that if the low frequency is possible I will also need a power transistor to step up to the voltage/current needed to operate the relay. Any help greatly appreciated........ Thanks, Peter :-)

Question by ppowell14    |  last reply


Schematics, Help Please

Hello, I'm trying to create a simple timer that sets off a device after a set amount of time. I'm using a schematic from a basic electronics book that my grandfather had given me a few years ago. And it seems simple enough to the point where I can understand how it works. But I just can't seem to figure out how to actually put it down on a breadboard to even test it. So if you could possibly help me find out how to place this down on a breadboard to at least test, I thank you very very much. -The picture of the schematic should be below.

Topic by caseyweed    |  last reply


How can I make a TV remote repeatedly send a signal? Answered

Hello everyone. My parents' big CRT tv has a problem with its psu. Its probably the psu's capacitors that have died again. So in order to turn the tv on they have to click the remote's power button again and again and again for at least ten minutes until the tv turns on. It's been repaired 3 times already and because of the repair cost it's not worth repairing it again. Also because it is very big and heavy and it's very hard to move it. Their living room requires a big tv screen but at the moment they cannot afford buying a new tv. This is how I came up with this temporary solution. Make a circuit that will automate the repetitive clicking of the remote's power button, scratch the remote's pcb paint around the power button and solder this circuit. Unfortunately I'm a beginner in electronics and I don't know how to do it. I can only assume that it is possible with the use of a 555 timer and a relay. This is where I need the community's help.

Question by myouknowwho    |  last reply


I just bought 7 555ic timers, all of them are faulty?

I bought 7    555ic timer. i tried to blink an led but the output always stays high. when i swapped the 555 by a 556 it then worked. first i thought that my circuit was wrong. i've verified it countless times all seemed to be good but the pin 3 output was always high. when i used the 556 timer with same components it worked. is the 555 timer at fault or i am missing something?

Question by ARJOON    |  last reply


could i use 2 555 timers instead of one 556?

There's a few projects that i wanna do but i don't have any 556 timers. but i do have tons of 555 timers

Question by madrobot3600    |  last reply


led display using 555 timer? Answered

Can anyone help me with a design , i would like to make a 5 letter display using leds that spells my daughters name "TRULY" lighting up each letters one at a time then having them all light up at once then repeat? i am new  and this will be one of my first rojects not out of a kit. any suggestions?

Question by vince26    |  last reply


7805 and 555 timer circuit heat.

Hi all! I made a test led blink circuit with a 555 timer on a bread board. Just a basic two led blink circuit you can find all over the place. I used a 7805 for a supply regulator with power from a 9v batt. The circuit functioned fine (to my knowledge), but the 7805 got REALLY hot. I've used 7805 in opamp circuits with a 7.2v batt and no detectable heat. Is what I'm experiencing normal? Or do you believe something I did was wrong. If I remember correctly (I'm really tired as I write this) i was using 100nf caps on both ends. Thank you Nic

Topic by Mrlzeppelin    |  last reply


Heartbeat Pulse+Speaker+555 timer

Hello all! I'm posting this idea that I have for making my wife a gift for our anniversary. I'm posting this in burning questions as my research time for this is rather limited as the whole project is to be a surprise. Here's what I aim to build... What I want to make is rather simple, I want to make a pulsating heartbeat sound through either a piezo speaker or just a small 2 inch or smaller speaker. The more compact the better as I plan to integrate this into the other half of my project. The problem is im not very familiar with the 555 timer, I normally don't use them in my projects as I try to work with AC most of the time. But that's another topic. So anyways, my idea is to set the duty cycle low so it's 3 quick pulses and then about a second of silence. I imagine programming in Arduino would be easier but therein lies the problem: I do not know how to program and every Arduino I have is fried. (I make good use out of my components!) This is when I turn to the community and sincerely ask for your help in making this possible. Someone who is more familiar and can quickly and conveniently answer this is obviously more then welcome! This is where I plan on getting most of my research done in my off time. Any help is greatly appreciated. If further explanation is needed please do not hesitate to ask. :-)

Topic by 49percentGood    |  last reply


How would make wire 555 timer to flash LEDS quickly every second?

How do you wire a 555 timer to do what you want ?

Question by planetroverrobo    |  last reply



How much do 555 timer chips cost? Answered

$1 for a pack of 250? Or $250 for a pack of one?

Question by bowmaster    |  last reply


need help on 555 110v timer.

Hey guys w up? i`m asking for help, i`m trying to develop (i have one, similar) a 110 v timer based on the 555 (or any other) i have seen many timers on the web but they run on 9v batt and i do not have room for the transformer , can u help me ??? all (just nothing) all i need is the electronic diagram . i need the timer to work on 110v and run two different cycles a: 90 seconds b: 180 seconds and cut the power. (untill you press the push button again) i have an electric diagram. tx so much. if you need help w something (i`ll try to help you if i can) even if you can`t help me ..ask e have nothing to loose.

Topic by scopevisions    |  last reply



Need "Timer" help right away. Automotive 12VDC

I need a 12 vdc timer that will pass thru 12v once activated, BUT only for about 1 to 1.5 seconds. Then it has to stop passing the 12v even though it is still powered (12v is the still being supplied). Once the supply voltage is removed, it needs to reset so that it can pass thru again the next time supply voltage is introduced. I can solder & read. That is about my limit of electrical circuits. Would an IC 555 timer be able to do this somehow? Thanks STEVE.

Topic by st600r    |  last reply


Delay for a timed switch?

Hi, I wont explain my purposes(maybe in an instructible if i get a good answer) but I need a simple(as in, requiring very few parts) schematic for a 555 timer. I need a setup where i have a battery, connected to a switch(the kind that you push, and it closes the circuit, then you push again, and it opens the circuit. I forget what its called) that goes to a 555 set to delay for 10 seconds. After the 10 seconds is up, it allows the electricity to go through. Anyone understand? If needed, I can upload a pic of what I need.

Topic by metrogdor22    |  last reply


How do I use a multiplexer? Answered

I have a bunch of assorted multiplexer chips I purchased in a grab bag a while back. I want to get my self familiar with them at the most basic level. I understand what multiplexing is by definition only, but not enough to really understand how to use one.  How would I go about testing out the pins for example, or is it even possible to use just 1 multiplexer IC with a 555 ic for the clock to understand what is going on?

Question by atrumblood    |  last reply


Time Delay Without A 555 Timer ?

Hello, When it comes to electronic circuits I'm a mix between a newb and a novice. What I want to do here is make a circuit closed for 3 seconds (doesn't have to be exact) then open till the circuit is reset. Is there a possible way to do this without using a 555 timer? Thanks in advance.

Question by Seifpic    |  last reply


Generating 40K Hz Audio with a 555 timer Answered

I'm looking for ways to generate a 40K Hz signal with a 555 Timer. I've been through the 555 timer calc and I'm not liking the values its wanting me to use for R1 and C2. So i found the schematic shown below. Will i be able to replace the IR LEDs with a small amp and speaker and get a good 40kHz tone out of it? Are there any better options i should be looking at for creating a 40K Hz audio signal?

Question by mpilchfamily    |  last reply


Will this 555 circuit for 8 leds flashing work? Answered

Will this 555 timer work and make these 8 leds flash with this circuit I drew up.

Question by mykiscool    |  last reply


Joule Thief w/ 555 timer

Hello, I have a question about using a 555 timer with a joule thief. I'm trying to build a circuit for some solar powered bike lights but I have a couple of questions... 1. Am I correct in assuming that it's a bad idea to try to run a TLC555 timer chip from the output of the joule thief? Without a load, it seemed to be pumping out at almost 80 volts. 2. I tried building the circuit so that the two rechargeable 1.2V batteries would power the 555 directly, and then the output would sink and source two transistors alternately, which in turn would switch the LEDs alternately, using the output from the joule thief, which was also powered directly from the battery. That resulted in no LEDs lit and some very hot transistors... Bad idea. The TLC555 chip is supposed to run on a supply voltage of 2-18V, but when I tested it with the 2.4V coming from the batteries, it would source, but not sink... Is there any way to build this circuit so the 555 could blink 2 LEDs alternately while the LEDs are powered by the joule thief? The only alternative I can see that might work would be to power the joule thief from the output of the 555 and just blink all of the LEDs at the same time from the joule thief's output. Any help would be appreciated!

Topic by amklose    |  last reply


Does a lithium polymer battery have too much amperage for a 555 timer? Answered

I'm using a 555 timer for a robot, and i was wondering, is a lithium polymer battery too much amperage for the 555 timer? because when i use it, the 555 timer warms up, to a point where i cannot touch it without getting burned instantly. If so, how can i reduce the amperage, so that it can be used with the 555 timer? I'm using a 7.4 volt, 1000mAh battery, it was originally used for a helicopter, but i re purposed it for my robot...

Question by Chowmix12    |  last reply


Computer parts and others

I just basically saying 555 timers, lm386, boxs of wires, computer parts like HDs and mother boards, leds, resistors, capacitors, and other electronic componets.

Topic by Kante Tech    |  last reply


how to make a 555 flash a led on for 1 second? Answered

And flash off for 1 second too, like a car turn signal? (i am trying to make a turn signal for a rc car project)

Question by zack247    |  last reply


Could somebody explain what the pins on a 555 timer do please?

Hey guys, I have the general knowledge when it comes to creating schematics and all but I do not undertand how a 555 timer is supposed to work. I simply want to be able to control some oscillation using a pot/rheostat. I already have resistors, capacitors, transistors, a power supply and a speaker but I do not know how I should connect them. Can somebody please explain how it would work?

Question by dipseydoodle    |  last reply


What a 555 timer does in layman's terms / simple universal timer

Hi folks,I'm helping my daughter make the universal timer kit linked below. She needs to be able to explain a bit about how it works. Everything I've found on the 555 timer is very complicated - we don't need how it ACTUALLY works as such, more a simple analogy.Something like that 'the circuits inside the chip switch on and off so that it outputs a pulse of power. controlling how much current goes into the timer regulates how fast it creates a pulse. This pulse gradually charges the capacitor. When it's full, it discharges and activates the buzzer.'Well that's the best I can do at this hour of the morning anyway! If someone could correct and add detail to this it would be very helpful!thanksHelenhttp://www.jaycar.com.au/productView.asp?ID=KJ8108&keywords;=universal+timer&form;=KEYWORD

Topic by ozgeek