Whats a 555 and how does it work?
Topic by colmon9 | last reply
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
Hi, to make a long story short i don't want to have to go into the cupboard and turn on my amp every time i plug it in, it has a button on it that needs to be pressed about 5 secs after power is turned on and then left like that, could i take a feed off the power supply, connect it to the 555 or another ic and make it activate a transistor 5 secs after power was applied? i only need it to do this once every startup, i don't want it pulsing on and off and it needs to be as simple as. thanks, luke
Question by ljarrald | last reply
Hey, so i wired up my 555, with a trigger button, and because i only had small resistors at the time, I used one to give a really quick period. however when i put in a brand new 800 KOhm resistor (that should have raised the period to 8 seconds) instead of lengthening the period it put a time limit on the trigger. so now i have an output that stays high for a faction of a second and then the chip can't be re-triggered for 8 seconds. i know people don't have an encyclopedic knowledge of 555, but does anyone more experienced have any ideas why this might have happened. thanks in advance.
Question by DrVonTrap | last reply
Evening all, This is most likely a very basic problem but for the life of me I can't find the solution. The project: auto folding wing mirrors (see below) http://www.lexusownersclub.co.uk/forum/index.php?app=core&module;=attach§ion;=attach&attach;_id=6108 The problem: for some reason my alarm logic is the opposite way round, most likely due to the removal of my motion sensor due to it tripping my alarm when locked. Now I have modified the circuit shown in the PDF to remove TR2 and R4 so the I/P to the 555 is kept high by the 12v alarm signal. I have a pot between pin 2 and ground so I can adjust the pull down point as the alarm signal only drops to 9.7V and, obviously, the 555 needs logic high or low. So, having adjusted the pull down point, I find that the 5 second timeout, which worked when I first built the circuit as per the PDF, no longer switches the O/P off. So so what am I doing wrong or is it just best to us a picaxe to do all of this as I code write up the code in half an hour or so. thanks
Question by LED Maestro | last reply
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
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
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
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
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
Hey guys, I have another question. I'm in the planning stages of a project, It's basically supposed to be an astable 555 sending out a frequency that's supposed to control the mark space ratio of another 555 that's going to send a signal to a servo motor, causing it to oscillate back and forth. Tl;dr, I want to make a servo wiggle around with two 555s. I have used the output of a 555 to modulate another one before, but I understand that using a 555 to control a servo is slightly different than just audio output. So is there anything I should be aware of? Is there anything I can read or look at to point me in the right direction? Thanks. EDIT: I just had an idea. What if I took the output of the first 555 (thus forth referred to as IC1) and used it to turn on a transistor, which connects a resistor in parallel to some part of the IC2 which decreases mark space and turns the servo. https://www.instructables.com/id/Simple-Servo-Tester/ This one uses some pots to control rotation, if a resistor is connected in parallel using a transistor... something will happen. It moves.
Question by mrmerino | last reply
I am trying to construct astable multivibrator using 555 IC that will drive my relay. I am trying to make it trigger every 15 min. but when ever it triggers, the 555 IC get overheated, I have burnt almost 10 of them. any idea what could be the reason? If I don't connect anything to pin-3, it works very well.
Question by dgogate07 | last reply
I've found numerous write-ups on getting a servo working with a 555 IC but it's not quite the functionality that I'm looking for. What I'm trying to do is have two buttons go to a predetermined position but the write-ups have two buttons that just go clockwise or counterclockwise. I know this can be done with an Arduino but I'm trying to avoid that route so I can keep the footprint as small as possible. I've attached a picture of the schematic I was working from.
Topic by XAlliedYouthX | last reply
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
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
Hello, I've been breaking my head on this for a while now, and still couldn't find a correct solution for this. I want to be able to adjust the duty cycle (pulse width) with one potentiometer, and the frequency with another potentiometer, using a 555 timer. Adjusting the frequency shouldn't change the duty cycle! (which is the problem in All of the circuits I find online). This is an example of a circuit I find online, many of the circuits look just like this one (see picture) Now, the problem is that when you increase the resistance of the potentiometer for adjusting the frequency, that makes sure you can never get 0% or 100% duty cycle anymore! or not even close to that. It's because increasing that resistance, also decreases the 'discharging current' of the capacitor, so it will also increase the discharging time when that's not wanted. Without R2 it works perfectly, from 0% to 100% duty-cycle; but with the frequency potentiometer it all gets messed up. It's a little difficult to explain, I'll try it with another example :) To get 0% duty-cycle (or something close to that, like 10%), you'll need to make sure the path for Discharging the capacitor goes near 0Ohm. Increasing the potentiometer for the frequency makes that impossible because it's in series with the capacitor's charging and discharging circuit. So that would also increase the discharging time while I don't want that. When the resistance of the frequency potentiometer increases, the duty-cycle gets variable between just something like 45% and 55% (example) so that's not good. Is there any way do do this? :/ Thanks in advance, Elecotrials
Question by DELETED_Electorials | last reply
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
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
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
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
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
Hi,I have a simple buzzer which I want to convert to an oscillating buzzer so as to obtain the sound similar to that of an automobile's reverse indicator.I've posted a schematic(borrowed from electroschematics.com) below.I intent to replace the LED with my buzzer and omit the resistor.I hope by building this circuit,to make my buzzer 'buzz'(or make noise) at an interval of 1 second(since its a 1 Hz pulse generator).Would the results be similar to my needs?
Question by Adarsh_tronix | last reply
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
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
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
I am attempting to recreate Duck210's guitar LED mod. However, I am having problems with the circuit. https://www.instructables.com/id/LED-Guitar/step3/null/#images As I have said, it gradually slows to an ultimate stop. Any ideas? Please help! Thanks in advance, ~H4ZZ
Topic by __DELETED__ | last reply
Hi, I'm wanting to put some led indicators in my car because they are so efficient but my current flasher unit isn't designed to run such a low load. It is also relay based which probably isn't the most efficient way of doing things and with it being an old mini it sometimes rattles itself at whatever rate it feels like flashing at at the time so I wanted to use a transistor instead. I've come up with the circuit attached and built it but when it is running all the indicator lights for the hazzards, the transistor gets hot! Surely there is a better way of doing it? Could someone have a look and see what could be changed? I don't know much about transistors but I know that I'd be better getting it to 'saturate' and act as a low resistance switch but I don't know how to achieve that. It also has to run under two loads, indicators and hazzards, and has to flash at the same rate for each - between 1hz and 2hz. http://www.dprg.org/tutorials/2005-11a/index.html I think a variation of this circuit might be better (it makes use of the discharge pin rather than the output pin), with the load at the ground side of the transistor because it has to be an output pin on the flasher unit. I've got some BFY51, BUY82, BD743B so it would be great to use one of them. in short: what's the best solid state fixed rate 12v flasher driver using a 555 that can supply around 2 amps using as few parts as possible? Thanks for your time, and sorry if I've done anything wrong!
Topic by arichardson | last reply
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
Well im somewhat novice and I was wanting to make a circuit to monitor the level of a 12v car battery with 3 LEDS (although more is cool) Yellow for low, Green for good and red for overcharge. Ive looked all over and cannot find a circuit that uses a single 555 ic to do this easy task.
Question by Sky Graham | last reply
Please advise on how to add an additional keyword to a published Instructable. I have tried adding the keyword "555" or "555Timer" to my recently published Instructable "Electronic Paperweight" but keep getting an error message. Editing the Instructable is no problem, but cannot add a new keyword.
Topic by TinkerJim | last reply
I have been trying to make cylon light bar thing. http://www.evilmadscientist.com/article.php/CylonOLantern but it isn't working, all the wires an connections are done according to what is said and i asked my neighbour to have a look he is a electrician and he was surprised it didn't go as well. its the NE555 i put it togther. looking down on the plastic. ______ 1-| o U |-8 2-| |-7 3-| |-6 4-|_____|-5 was that the wrong way? i have seen other circuit diagrams and the pin numbers where not like that. thank you oh and also is some solder non-conductive? and can you burn wires and make them useless? i don't think i could have fried the chip i getting pro at quick soldering.
Question by Scotty3000 | last reply
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
I would like to replicate the Hitechnic IR Beacon. Essentially, this means that I need to create a 1200hz square wave. I would like to do this with a 555 timer, a 3v power source, and infrared LEDs (1 - 3). Please offer any suggestions you might have. This will work in conjunction with the Hitechnic IR Seeker and an NXT Bot that I will program in RobotC. Thank you.
Question by raykholo | last reply
Question by gr33ko | last reply
Will this 555 timer work and make these 8 leds flash with this circuit I drew up.
Question by mykiscool | last reply
I would like to build a circuit where I push a button once and a servo moves 180 degrees and stays there. If I push the button again it should move back to the start position. A switch is good alternative, whichever would be easier. I've been looking at circuits to do with 555 timers and servos and have found these two which seem useful: http://www.555-timer-circuits.com/servo-controller.html http://www.dummies.com/how-to/content/electronics-components-555-timer-chip-in-monostabl.html Is that second circuit what I need? How would I change the direction of the servo each time it runs? I looked into flip-flops such as the 4013 which came up as a suggestion instead of a 555 but quickly got out of my depth. I'm happy tinkering around with electronics but unfortunately don't know too much of the theory...
Question by Sparrowhawk | last reply
Or any other easy way to create a certain number of pulses? The amount of time this happens in doesn't really matter. The o/p of this pulse generator must have enough voltage/ current to power the clock of a 4024 7 bit counter
Question by hrimiller | last reply
I'm trying extremely hard to figure out how to make an led throb with a 555 timer using PWM. What I have figured out how to do so far is how to make a 555 circuit with a potentiometer and manually throb it with the pot. But I don't want to just keep turning the pot to throb the led. Is there a I can put a potentiometer in the circuit to control the speed of the throb rather than dim the led? I need to use PWM for the throbbing. And the throbbing speed needs to be adjustable with a potentiometer. I'm really new to circuits, but I'm learning a lot. Can someone point me in the right direction? This is an extremely important project for me.
Question by SpiffyChee | last reply
Question by 1loloo | last reply
I was thinking about making an intervalometer circuit for time lapse use on cameras. I was thinking of using this link https://www.instructables.com/id/Time-Lapse-Intervalometer-for-SLRs-with-555-timer-/ . I was thinking of adding a 22uf cap, as well as the normal 220uf cap, and then adding a 2200 uf cap, for a highly flexible range of time (ranging from a few seconds to about an hour), choosable by switch. I am starting to run into trouble at the camera connection itself. While i am fine with a cable, i would rather go with a wired remote, and using it to do the equivalent of pushing the remote buttons (instead of going through the cable itself). So i need a way to connect the two switch points electronically, rather than mechanically. Also is there a way to have it focus first, then take the photo? This circuit would also be good for cameras that do not have remote connectors, just go in to the camera and solder the switch points up, then hook them to this circuit. Would also work with a wireless remote. Hook it to the remotes switch and go from there. Just need a little help finding out what to do to get it to work the way i want to :) Thanks
Question by astroboy907 | last reply
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
The circuit is to provide a pulse to a 4017B decade counter to count up to 5 minutes
Question by ralph4ed | last reply
Ok so my handicapped uncle has a 3 wheeler bike that he goes everywhere in day or night and I'm always worried about him being hit by a car in the dark so i wanted to make a light bar with 7 orange led's so he could be seen by cars and then i though of incorporating a solar panel so he wouldn't have to charge battery's (the battery's charge while hes out during the day and light up at night) but now i think it would help if the led's were to flash i have a few 555 ic's but I'm not to sure how to use them id like to use one in this light bar to make them flash heres a sketchup model of the lightbar http://sketchup.google.com/3dwarehouse/details?mid=60db9f5dd7284717d25303acb02b2c20&prevstart;=0 thanks in advance Ps i also have some pcb boards if needed PPS if there are any improvements you would like to suggest these are apreciated PPPs if you would like to add the 555 circuit to the sketchup models email it to me at email@example.com Thanks! thanks for your help in advance!
Question by brl60 | last reply