NE555n timer or NE555p timer? Answered

Please Help. I want to know if I should buy a NE555n timer or a Ne555p IC. Can I do the same things with each? Is there much difference? Thank you guys, Electronicsloser

Question by HavocRC   |  last reply


Automotive Power Loss Annunciator

The photo shows what I'm dealing with: a sound module ($2.50 including shipping from China) and an automotive auxiliary power cord (cigarette lighter.) The sound module has a "play" button at the end of the yellow wires. The "black box" has two tasks:                 - detect loss of power on the 12V cord                 - momentarily connect the two yellow wires (as if the button switch had been pressed.) So far I’ve been told that some sort of relay and a timer could be involved, but since I’m not a Electrical Engineer, I don’t know the specifics. I know that in the automotive world, there are big, bulky relays, but I'm wondering if there are relays in the integrated circuit world? I really need specifics like part numbers and circuit diagrams. Thanking you in advance for your help.

Topic by willy41   |  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


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



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


How to fade a led in over 10 minutes, using cheap ic's? Answered

I want to fade in 4 leds over a period of 10 minutes then have then turn off after another 50 minutes or so, voltages of leds dont matter. Any ideas would be great! Thanks Cybot

Question by Ralim   |  last reply


Can I use a 555 timer IC to make an amateur radio?

                    I'm thinking about starting to do amateur radio, but I don't want to pay a ton of money for a transceiver.  In theory, couldn't I use a 555 timer with a frequency modulated by a microphone to generate FM, which could then be amplified and transmitted?  Just curious about it.  Also, couldn't one do the same thing in reverse, just finding a way to tune a 555 or something so that it would output audio when tuned to a specific frequency from an antenna?  Just a thought. 

Question by mad magoo   |  last reply


which IC does sonic screwdriver's circuit use?

I want make a screwdriver but dont want spand 10 pounds to buy a new one and take it apart for a circuit, i want make it under 2$, which IC does they use in the toy? 555 timer? can provide organial circuit desgin? thanks alot

Topic by EthanY   |  last reply


How to use a 555 timer to switch a switch? Answered

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


Flashing/Pulsating 10mm Red LED voltage

I just finally got the throbbing/flashing/pulsating LED, but a 9v battery doesn't seem to be cutting it. I bought the 10mm LED from Radioshack here. I was just wondering how high I could go in terms of power. I was thinking about a 10v DC, and go to a 12v. But I don't want to blow the LED. I was also wondering how I can get the LED to flash slowly, like it was "breathing". I started off with a 1000µf 16v capacitor, then went down to 470µf 25v capacitor, with no significant change. I also have a 470ohm resistor that I got with my 100 pack of white LEDs. Any recommendations would be appreciated.

Question by Lazarus65 


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



555 timer to make led's flash in this circuit ?

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 brl1995@hotmail.com Thanks! thanks for your help in advance!

Question by brl60   |  last reply


Current in IC chip

Hello, It's a bit stupid to ask (I think), but essential to me. From all schematic I readed over intructables I never saw anything or anybody that cared for that. If a IC have a maximum and minimum current to respect ie: 6mA to 10mA, do we even care? Do I need to limit the current somehow? As I said, every schematic I readed never added any resistor or talked about anything relate to limiting the current on the VCC for the integrated circuit. I'm currently building a device that use one 555 timer IC in astable and a few others IC and they are all connected in parralel to the power suply. Thanks

Topic by sxdemon   |  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


Different wait times in IC output.?

Hi, is it possible to make an output with different Wait Times? The numbers are the time in seconds. The HI would be the enough to make a buzzer beep, like half a second... I was thinking of 555 ICs, but I don't think it's even possible to do this with them. Do you suggest any IC that can do this? I just want a buzzer (or whatever) to beep like: Power On - 30sec - BEEP - 180sec - BEEP - 30sec - BEEP - 180sec - BEEP, etc Thanks.

Question by pedrotome   |  last reply


On the 555 Timer Schematics I found I need help deciding what transistors to use to build it? Answered

I am a beginner in electronic schematic reading and I want to build a full sized 555 timer with all the parts that make up the tiny little IC. But I am having trouble determining what transistors to use. This schematic has the details on what values of resistors to use but not what transistors they are: http://www.electronics.dit.ie/staff/mtully/555%20folder/555equiv.gif Which ones should I use? same thing with this one: http://eliot84.files.wordpress.com/2009/09/ne555-schematic.png This one seems pretty promising since it does list what transistors to use: http://ssihla.files.wordpress.com/2011/02/555.png and I don't know this one is hard for me to understand: http://analogguru.an.ohost.de/193/schematics/Dod_555.gif Which one do you think is best or what transistors could I use in either of the first 2? Is the last one actually a 555 timer or is it something else?

Question by powerman666   |  last reply



Repeating Musical Greeting Card?

Hello all,  I have purchased an inexpensive musical greeting card that plays a song for 20 seconds and then stops. What I am trying to figure out is if there is a way to put a 555 timer on this thing that will send a pulse to repeat the song at 15 seconds. Basically, make it so that the card will repeat the song forever at 15 seconds so that you don't hear the fade out of the song for the last 5 seconds.  Can this be done and if so how? Many thanks!!! Wes

Question by wfunderberg   |  last reply


How do you make a digital counter circuit which counts to 10 minutes, it will rings a buzzer and when it continues to 15 minutes, it will rings a buzzer?

I need to make a digital counter circuit which it counts to 15 minutes for my big project in my campus . When the circuit counts to 10 minutes, it will rings a buzzer. Same when it continues to 15 minutes, it will ring a buzzer again. (the circuit is for public speaking, so the speaker knows that he or she already went speak for 10 minutes and 15 minutes). We weren't allowed to use an Arduino, Microcontroller, PLCs, IC NE555, and a 4000 series CMOS IC but we were allowed to use breadboard, flip flop, decoder and 7 segments display. I'm kinda stuck here and I'm thinking it's impossible to make such a thing. Do you have any idea guys?

Question by Najedfahad14   |  last reply


What can I do with piezo buzzers/sirens/beepers, switches, safety switchs, and other basic components?

I have some components I really like, but I don't know how to use them!!!  (resistors, leds, 555 timers.. etc.)? relays even?

Question by sjoobbani   |  last reply


Where can i find (scavenge) a 555 timer and other commonly used ICs? Answered

I have a special interest in components retrieval from out or no-more-in-use eletronics, and since i live out ou the US that is probably the easiest/cheapest/quickest way to get some parts. A mini-question: what is the main application of the 555? I've seen it mostly controlling dc motors and blinking lights and in some amps. Knowing the use of it is another way to know where to find it. So, just like a stepper motor can be found in most (if not all) printers and scanners, where can we find ICs and other crucial parts for projects?

Question by vinacarv   |  last reply


I have this circuit of a servocontroller using two 555 timer IC's. How can i make impressive modifications?

Http://hades.mech.northwestern.edu/wiki/index.php/555_Servo_Circuit this is the link to the circuit...It requires two 555 timer IC's...How can i make it more impressive looking?

Question by Yashknowsbetter   |  last reply


How do i make a 555 IC timer chip make two leds flash back and forth like a light bar?

What i am trying to do is make my leds flash at different times. i have a 555 IC timer chip and have found how to make a single light flash using resistors and capacitors. How would i go about making two leds flash back and forth. Any information in regards to this would be greatly appreciated.

Question by CertifyThis   |  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


led flash and fade. how?

Video of RavelightPicture of RavelightIm interested in building a product that utilises coloured LED lights with multiple flashing and fading patterns.I have pulled apart a few LED products and examined the PCB's and the components and have a general idea of what is going on, however it is all new to me, and im unsure of the possibilities that exist. For example, i didn't know you could get pcb's so small...Basically i need the power source to be the small button cell batteries (up to 6 if necessary, though 3 or 4 would be preferable). With at least 4 LEDs of different colours (RGB etc). A similar design to what I want to make is a flashing LED light stick like people use at raves that I found. It has a button that seems to simply complete a circuit momentarily, and pressing it down again and again, scrolls through its 9 different flashing patterns.I have seen various different LED toys that vary on this, but are basically the same idea.The thing that I don't understand (on top of a lot of other small things) is what is under the black blob on the PCB? Is this something like a 555 timer? an IC? And how are these programmed to give all the different patterns? is it a microchip?This thing cost me $3 from a shop. three dollars!! cheap as....this is what I want for my product. can anyone help me out to understand?I can post a picture up in the next couple of days if people can't understand what i'm talking about.Thanks

Topic by noi noi   |  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


(SOLVED) 555 LED flasher slows...

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


Can you help me convert some Basic code to Processing code for calculating 555 IC timing?

I want to modernize this BASIC code that I found for calculating the values of capacitors, or resistors to use for timing with the 555 IC. /* This BASIC code taken from the Ramsey Electronics Universal Timer - Oscilator Kit UT5 instructions I decided to convert it into processing since no one really uses basic like this anymore. But you still can. I don't. 10 PRINT "FIND FOR TIME [T], MICROFARADS [C] OR OHMS [R]?" 20 INPUT "ENTER SELECTION: "; X$ 30 IF X$ = "T" THEN 100 40 IF X$ = "C" THEN 200 50 IF X$ = "R" THEN 300 100 INPUT "C1 in microfarads = ";C 110 INPUT "R3 in ohms = ";R 120 PRINT "TIME (seconds) ="; (1.1 *C*.000001)*R 130 PRINT 140 GOTO 10 200 INPUT "Desired TIME in seconds = "; T 210 INPUT "R3 in OHMS = "; R 220 PRINT "Required capacitance in ufd. = "; T/(1.1*.000001*C) 230 PRINT 240 GOTO 10 300 INPUT "Desired TIME in seconds = "; T 310 INPUT "Value of C1 in microfarads = "; C 320 PRINT "Required value of R3 in ohms = "; T/(1.1*.000001*C) 330 PRINT 340 GOTO 10 */ /** typedinput taken from http://wiki.processing.org/index.php/Typed_input @author Tom Carden */ // code was also taken from: // Learning Processing // Daniel Shiffman // http://www.learningprocessing.com // Example 18-1: User input // Variable to store text currently being typed String typing = ""; // Variable to store saved text when return is hit String saved = ""; String typedText = "Find for time [T], microfarads [C] or ohms [R]?"; PFont font; void setup() {   size(640, 480); //bigger window. Orginal code has small window   font = createFont("CourierNew", 18);   //fixed width font rather than other ugly font   //suggested in original code. } void draw() {   /*is this like the equiv to loop in arduino? I don't know I hate this language anyway. BASIC is easier to follow, but I wanted to make this program easiliy accessible for modern people.*/   background(255);   fill(255,0,0);   textFont(font,18);   // this adds a blinking cursor after your text, at the expense of //redrawing everything every frame   text(typedText+(frameCount/10 % 2 == 0 ? "_" : ""), 35, 45);   //nice touch orginal coder! } void keyPressed() {     if (key == '\n' ) {     saved = typing;     // A String can be cleared by setting it equal to ""     typing = "";   }   if (key == 't' || key == 'T') {     typedText = typedText.substring(0,max(0,typedText.length()-1));     TIME();   }   if (key == 'c' || key == 'C') {     MICROFARADS();   }   if (key == 'r' || key == 'R') {     OHMS();   } else {     //value = 0;     typedText = typedText + key;   } } void keyReleased() {   if (key != CODED) {     switch(key) {     case BACKSPACE:       typedText = typedText.substring(0,max(0,typedText.length()-1));       break;     case TAB:       typedText += "    ";       break;     case ENTER:     case RETURN:       // comment out the following two lines to disable line-breaks       typedText += "\n";       break;     case ESC:     case DELETE:       break;     default:       //typedText += key;     }     if (key == 't' || key == 'T') {     typedText = typedText.substring(0,max(0,typedText.length()-1));   }   } } void TIME(){    background(255);   fill(255,0,0);      typedText = "\nC1 in microfarads = ";      //typedText = typedText.substring(0,max(0,typedText.length()-1));      //typedText += key;      //keyReleased();    } void MICROFARADS(){} void OHMS(){}

Question by powerman666   |  last reply


Easy automated method to find chronological age of an integrated circuit design? Answered

This is not a question related to a homework or career assignment. This question is an existential question. Specifically, the thing that I am wondering if it exists, or not, is an easy and automated method for finding the chronological date, e.g. a year, Anno Domini (AD) or Common Era (CE), when a named integrated circuit (IC) was introduced.  Preferably this method exists in the form of a free resource on the Web. As an example, the well known 555 timer IC was introduced in the year 1971, and I am reasonably confident that was the year, because the Wikipedia article titled "555 timer IC", https://en.wikipedia.org/wiki/555_timer_IC contains the words: "Introduced in 1971 by American company Signetics, the 555 is still in widespread use..." And I assume that statement is totally true, because if I can't trust the people who edit Wikipedia, I mean, who can I trust? ;-) Unfortunately, Wikipedia does not have a fact-filled article for almost every IC every sold.  In contrast, a place like www.alldatasheet.com has data sheets for almost every IC ever sold, but, it turns out, the data sheet does not always reveal the year the IC was introduced. To clarify this further, the thing I really want to exist, would be like a web site, with a name like: www.howoldismyic.com, or www.howoldisthisic.com, or www.icdob.com etc. (Please note that none of those URLs point to actual existing web sites, at the time of this writing.) Moreover, I am fantasizing this web site would contain a form, for to enter the name of the IC to look up, and then after hitting the "Submit" button, it would magically tell me what year that IC was introduced to the world, and maybe also which semiconductor company gave birth to it. As some example input and output, the query NE555 would return:  NE555, 1971, Signetics(r) As an additional twist to this fantasy, the query, LM555, would return the same thing, and this magical web page would like, know, that LM555 was a later version of the same IC, except produced by a different manufacturer, namely National(r); i.e LM555 was National's version of the 555 timer . If you have read this far, I congratulate you!  And I appreciate your eyeball time! If you are wondering about my motivation for this question, it is just that think the year an IC was introduced would be a very useful metric, like for answering more specific questions, like: The SG3524 and LTC3780 are ICs used for making switchmode power supplies.  Which of these ICs is more modern? I.e which IC was introduced latest? It turns out, the answer to this question is: The SG3524 is older (introduced first).  The LTC3780 is younger (introduced second). The SG3524 was introduced (I am guessing) in 1977, and that guess is based on some cryptic scribbles in a data sheet for the SG3524, published by Texas Instruments(r). The exact characters were: "SLVS077D – APRIL 1977 – REVISED FEBRUARY 2003" and I am just naively interpreting that blurb to mean the SG3524 was introduced in 1977. Regarding the LTC3780, I think it was introduced some time in the 1990s.  Looking at its datasheet, from Linear Technology(r), I could not find an obvious description of what year it was first introduced, but the first page mentions some US Patent numbers, and looking up those patent numbers, gives dates circa the early 1990s. So the LTC3780 is the younger than the SG3524. However to find that answer, I kind of had to do a bunch of reading of datasheets, and US Patent numbers, and that method took a little bit of work. My question:  Is there an easier way to find out how old (or young) an IC is?  More specifically is there an existing resource on the Web, like a free database, or a IC history site, or something where I can essentially "look up" the year an IC was introduced. By the way there is no absolutely zero urgency attached to this question.  So please answer if you feel like it,  and don't if you don't. I thank you for reading this.  My name is Jack A Lopez, and I approve of this message.

Question by Jack A Lopez   |  last reply


I have a question about the wiring a 555 Timer in Monostable Mode?

Hey all I am relatively new to the world of electronics. I have been learning about the different modes of the 555 timer chip because I would like to incorporate it into an upcoming project. I made a circuit and did the calculation so that once a button was pushed, an led would stay on for 5 seconds and then go off (a one shot timer). Everything worked ok accept I noticed that when hooked the battery up to the bread board (my last step of the build) the LED would turn on stay on for 5 seconds then shut off.  Is there a way to wire it so that when power is initially applied to the circuit it doesn’t trigger the timer? In other words the only thing I want to trigger the chip is a push of the button, nothing else! please let me know if this make sense. Thanks!

Question by Mpc1055   |  last reply


Can I use regular printer paper to transfer my design to my copper clad board? And if not, Why?

Im making a printed circuit board for a 555 timer ic and im wondering if using regular printer paper for the toner transfer will make a difference in the quality of the board.

Question by newwarhammer2   |  last reply


Led flasher 555 delay-off help!?

I have a working 555 flasher circuit:  http://www.555-timer-circuits.com/flashing-led.html - i have added a switch between the + and the board, and replaced the R2 with a variable. Works great! Now i would like to add a "delay-off" function, if thats what it is called, so a single activation gives 10 seconds of flashing. So, any advice? PS: I have pnp & npn's, resistors etc, but no relay's. Thanks fella's!

Question by R3born   |  last reply


Does solid state relay needs a protecting diode for the pin 3 out of a 555 monostable? Answered

Recently i need some timer for my capacitor charger to be used in a coilgun. i just finished a 555 one shot monostable pcb design.  my charger require about 24 watt of power which is unsufficient for the 555 pin 3 out,. I know that a protecting diode can be put with a relay. but a solid state for a solid state realay. does it need a diode. i just want to know because i will put it in my design 

Question by ARJOON   |  last reply


I already built a metal detector by using 555 timer IC. My problem is 10mh inductor? Answered

Can you give me a details of 10mh inductor? 1. The number of wires? 2. The number of turns? 3. The coil diameter? 4. The coil length? Thank you. I am hoping for your sonnest reply.

Question by teodygwapo   |  last reply


how do i set up this rf 433mhz receiver to trigger a servo motor?

I have a project of dropping a package from the belly of balsa aircraft wireless. for that i m using servo motor and wireless TXr and RXr and IC 555 timer. can anyone help with the circuit diagram. any kind of help will be appreciate.

Question by hiren_rock1   |  last reply


LM2576SX-5.0 VS LM2576SX-3.3,which is better?

Please Help. I want to know if I should buy a LM2576SX-5.0 timer or a  LM2576SX-3.3 IC. Can I do the same things with each? Is there much difference? Here is the datesheet:   LM2576SX-5.0 datesheet LM2576SX-3.3 datesheet Thank you guys, Electronicsloser

Question by DELETED_MakiY2   |  last reply


Can I use regular printer paper to transfer my design to my copper clad board? And if not, Why?

Im making a printed circuit board for a 555 timer ic and im wondering if using regular printer paper for the toner transfer will make a difference in the quality of the board.

Topic by newwarhammer2   |  last reply


Will and 8 ohm Speaker work where a 32 ohm Speaker is needed? Answered

I am asking because I bought this sound generator kit that has a 32 ohm speaker with it. But what I ultimately want to do with it is actually have a line out in order to hook up to external amps. The speaker is connected to a 15 ohm resister that is connected to pin 3 of a 555 IC on one side and the other side of the speaker is connected to a 10uf capacitor. The kit is the C4722 10 Note Sound Synthesizer from Chaney Electronics the circuit is similar to one i built and made an instructable for. On that one it has similar parts but the speaker is connected to one 10uf capacitor and negative. Do you think if I omitted the 15 ohm resistor I would be able to connect an 8ohm speaker or a line out? I haven't tried anything yet. And I haven't started to build my box yet since I don't know if am going to have to use the speaker that came with it or if I can modify it they way I desire.

Question by powerman666   |  last reply


S.O.S. LED Flasher Schematic Diagram

'Hello everyone,I looking to find an electronic schematic of a small LED flasher circuit thatflashes an S.O.S. light code. 3 short flashes, 3 long flashes, and 3 short flashes, than a 5 or so second delay, than repeats.Hoping to us a 555 timer IC.This is for a science project for my 14 year old.HELP! Thanks.Anyone?'

Topic by mark liles   |  last reply


Needed urgent help of expert in electronics please...?

I was looking for electronic mosquito repellent circuit, I just google it and wow.... there are hundred of schematics. Any one can tell me which one can work perfectly and.... If I setup 555 timer IC circuit for 10KHz and add a 8 ohm speaker between 3rd pin and battery positive will the speaker give the sound of 10KHz??? Please answer. Thank you in advance.

Question by njrajgelani   |  last reply


i was wondering if anyone can look at my atari punk circuit and see if maybe im missing something.

I put together a apc on my bread board using 2 555 timer ic's, looking at the schematic is seems like i did everything right, but i cant get it to produce a sound. hopefully you guys can spot what i did wrong. 

Question by skatattookid   |  last reply


I think I am starting to really lose it....

I was building the "Evasive Beeping Thing" from Make. A search through all of my "parts" finally got me resistors and caps of approximately the correct values I wanted *even though they are not specified in the article :-( ". After nearly a fortnight, I finally was ready to test it. hooked up a nine volt battery, and.....nothing. Fearing the worse, I touched the 555 IC...and it was hot as blazes. 2 days of inspecting the circuit and trying to make sure no shorts were occurring, I finally gave up and unsoldered the whole thing. I then through together a quick 555 timer circuit using an ic socket, in order to test if I had destroyed my IC. That didn't work at first (but just in case, I tried a 555 I knew was good, and that did work). Just before throwing out the assumed defunct 555, I looked at it under a brighter light (and low and behold, on the IC was written in very small worn type: 741. It was an op-amp ! I could have screamed....*sigh*. Oh well, at least I got a tester out of the deal LOL *sigh*

Topic by Goodhart   |  last reply


How to reverse the rotation of a vacuum cleaner motor? Answered

I'm possession of a vacuum cleaner engine and I'm trying to reverse its rotation..So far I've tried reversing it's polarity with no success but I looked up the 2 ICs on it's chip and it has a555 timer and a 7-stage binary counter.(see: http://www.standardics.nxp.com/products/hef/datasheet/hef4024b.pdf)There are only 2 wires running to the engine from the chip so I presume there is no feedback.Furthermore there is a potentiometer hooked up to both the ICs which regulates the speed of the engine (and no AD convertor as far as I can tell) so the voltage changes the PWM output as the engine is rated 230V.All ideas are welcome =)p.s.(I can't supply you with pictures right now, sorry)

Question by Prodigity   |  last reply


Do I need to protect my 4024 if I'm using a 555 for the clock signal

If I am using a 555 timer IC in astable mode at a running speed of about 1hz at 9 volt and pin number 3 (output) will be connected to a CMOS 4000 serie counter, (MC14024BCP package), do I need a resistor on the output of the 555 to protect the 4024 or it's ok and the 4024 will draw exactly what it need for his input?

Topic by sxdemon 


how can i make a mini project with microcontroller and what is your suugestion for me..?

Friends i am doing Electronics and Communication Engineering,3rd year,so i like to submit a paper for a mini project event ,as it is new to me,i am blanked of what can i do,so please help me what are all the project that i can choose related to my department ECE..waiting for your reply's. it might be from Micro controller,alarm,timer,ic,

Question by mani4astro   |  last reply


can anyone help me make a circuit for a EL wire driver? Answered

Hi  i live in a area where el wire drivers are not available however i can get all the parts to make one i know that i need to step-up a 9v battery to 130v at around 2000-3000 Hz  to make it glow  i want to keep it simple and not make it blink thus eliminating any kind of timer or ic can anyone please help me with a circuit design and the parts required thanks a lot

Question by cfrek   |  last reply


Will an IRFP 50 do the work for this schematic?

I recently made a some hv experiences. i made a 555 based ic timer along with and irfp 450 and worked great. but now i want more juice. i found this schema on the net and i was wondering if irfp 50 will work. i found those irfp in an old matsushita photocopier ( great stuffs inside)... those mosfet are quite expensive that is why i am just wandering if they could do the work.

Question by ARJOON   |  last reply


using 1 watt LEDs with a 4017

I want to build a chaser type light array using a 4017 counter divider circuit, 555 timer and the ever popular 1 watt luxeon LEDs, but I don't think that the 4017, or the 555 can withstand the current that will be going through them. I know in most cases you can simply toss a heatsink on the component and it will be fine, but I don't know if this will work with the ICs. https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId;=10001&catalogId;=10001&productId;=12749Here is the spec sheet for the 4017. Thanks

Topic by John Culbertson   |  last reply