60 Threads found on edaboard.com: 555 Time Delay
Do you need to do it with flip-flops?
Can you use a one-shot? A simple 555 circuit can do the trick for you.
Electronic Elementary Questions :: 20.12.2007 20:54 :: VVV :: Replies: 4 :: Views: 700
Hi guys,is there anyway I could get time delay using D Flip flops?I've tried googling it but all I get is info. on 555 IC timers.
Electronic Elementary Questions :: 13.01.2010 11:27 :: mngeow :: Replies: 6 :: Views: 962
I find the make monostable time delay IC.
What kind of IC exist? (except lm555 IC)
Analog Circuit Design :: 08.06.2011 06:39 :: purpleanger :: Replies: 1 :: Views: 678
See this circuit maybe you will find something usefull for you :
Three Stage - Cycling timer Circuit
Stage time delay Circuit
Analog Circuit Design :: 19.07.2013 11:44 :: tpetar :: Replies: 2 :: Views: 497
You can use a transistor in series with the motor and put a RC circuit on the base. Or you can use a cmos 555 timer in the one shot (monostable) mode and an AND gate which will drive the transistor base.
Hobby Circuits and Small Projects Problems :: 13.07.2004 20:14 :: flatulent :: Replies: 4 :: Views: 1407
I need to build a simple delay off timer. When the input is triggered (pulse only) the output must go high and stay high for a period of say 1 hour or 4 hours or selectable. When the input is triggered again, the output timing is restarted.
Any idea's? Would a 555 timer work? Not sure about the long (...)
Professional Hardware and Electronics Design :: 20.11.2006 04:11 :: mikesmixes :: Replies: 1 :: Views: 2253
Say i want to have a motor running, and i want to hook up a 555 timer so that when i turn off the motor switch, the motor continues to run for the time i have set on my 555 timer. I dunno how to hook this up, especially as i don't want to interupt the power to the motor, not even momentarily as i turn off (...)
Hobby Circuits and Small Projects Problems :: 14.10.2008 04:28 :: mvagusta :: Replies: 6 :: Views: 4496
You may want to describe the intended circuit operation more clearly. To my opinion it's hard to understand either from the circuits or your description.
Generally, introducing a delay in the said range involves capacitors of about 1000 uF. It can be implemented more easily with active parts, either timer circuits with 555 or transistors (...)
Hobby Circuits and Small Projects Problems :: 25.04.2009 07:32 :: FvM :: Replies: 6 :: Views: 3095
You really need to post your schematic. No one is going to know the exact Maplin circuit you "robbed".
Take a look at:
This is the basic 555 monostable circuit. One problem is charge stuck in C1. If you close the switch for several seconds, open the switch and then close it again quick
Hobby Circuits and Small Projects Problems :: 18.05.2009 22:42 :: banjo :: Replies: 4 :: Views: 9453
In the net, you can search the 555 timer tutorial of Tony van Roon. It is clearly mentioned there and you can be clear about 555 timer.
Analog Circuit Design :: 09.08.2009 04:51 :: Tahmid :: Replies: 1 :: Views: 1539
There used to be an 8 pin IC for automotive use, that had capability from 3.7 secs to many hours, it had a built in ripple counter so that timing components could be small and more accurate. I really cannot now remember the part number, which is a pity, as they were very reliable in noisey enviroments. You may be able to find something similar, oth
Analog Circuit Design :: 12.04.2010 11:49 :: GrandAlf :: Replies: 2 :: Views: 2783
I have an intresting project i wanted to build and i bit off a bit more than i can chew. the basic idea would be a couple of 555 timer hooked up like in a diagram i got out of make magazine volume 10( i will include the diagram) to make a buzzer go off after a 5 second delay. what im having trouble with is the math for what resitors and (...)
Hobby Circuits and Small Projects Problems :: 23.08.2010 20:16 :: mike134 :: Replies: 1 :: Views: 1616
I'd like to design a circuit such that at first, the circuit is completely powered off. The user pushes a switch, which injects power into the circuit. Then a mechanism maintains the power active, even if the switch has been released. At a later about 3 seconds, when the circuit does no longer need power,
it cuts its own power and sleeps u
Analog Circuit Design :: 20.05.2011 02:00 :: purpleanger :: Replies: 6 :: Views: 933
I need to know if the 555 is using any power at all while waiting for the button to be pushed.
A standard bipolar 555 has a rather large supply current of several mA, CMOS 555 still up to several 100 uA. Refer to the data sheets for details. So you would want to disconnect the power supply in idle state or use a RC + CMOS monostabl
Electronic Elementary Questions :: 20.05.2011 14:54 :: FvM :: Replies: 2 :: Views: 1235
Hey,Man who can help me to design a circuit which will activate a relay after 45 minutes during 10 s,I don`t want to use PIC or an other microcontroller type.
I would like to use logic circuits like cd4060,monostable like ne 555 and so on--
Any suggestion is welcome!!
Electronic Elementary Questions :: 18.08.2011 13:04 :: john120 :: Replies: 5 :: Views: 858
The formula is:
T = 1.1 * Ra * C
C could be 470uF or 220uF in your case.
I already used 555 for such long time to control my 3 refrigerators so that they start one after another when mains voltage returns after cut-off.
PS: The leakeage current of C will affect the time, by making it longer. But if it is relatively high then (...)
Analog Circuit Design :: 09.11.2011 11:33 :: KerimF :: Replies: 4 :: Views: 805
From what you describe you need two stages of timers.
1: delay after initial sound begins (or ends?)
2: 'on' time for activating equipment
It may be easiest to use a second 555 IC. There's the 556 which contains two 555 in one package.
Otherwise if you are willing to experiment, you can use a (...)
Hobby Circuits and Small Projects Problems :: 31.01.2012 18:12 :: BradtheRad :: Replies: 4 :: Views: 1973
Sorry for being so unclear.
The fan is mains (220V) operated, and the toggle switch is part of the mains power, switching the lights on-off.
The delay off electronics is 12 V operated, and gets its power from the permanent phase and zero lines.
The coupling between the low V and the high V circuits is made with relays.
The referred to
Hobby Circuits and Small Projects Problems :: 05.08.2013 01:09 :: Yossef Gofer :: Replies: 2 :: Views: 374
I need a timer that after applied 127VAC/60Hz it counts let's say 20 seconds and then turn on a relay and stays on, using a transformerless power supply and a LM555 timer.
Hobby Circuits and Small Projects Problems :: 06.05.2005 19:30 :: fjpompeo :: Replies: 5 :: Views: 9354
If you can put your circuitry inside the amplifier box, you can use a 555 timer to make the time delay for the relay closing. For the resistor, just put it from the capacitor output to ground.
Analog Circuit Design :: 24.01.2006 01:19 :: flatulent :: Replies: 12 :: Views: 1092
for this you have to connect it with the ldr tha a delay circuit and then a 555 timer it will gives you more accurate idea how the circuit hsould work
Electronic Elementary Questions :: 03.02.2006 07:45 :: vicky :: Replies: 5 :: Views: 2323
use a TSOP 1738 receiver which operates at 38jHz
search d net for datasheets......very easy to use
and for d transmitter u can use IR LEDs u can generate 38kHz freq using 555 timer as astable multivibrator or retriggerable monoshot having small time delay
use bursts of these 38kHz freq signals aimed at d TSOP 1738 sensor.
Electronic Elementary Questions :: 23.08.2006 02:29 :: alvarorahul :: Replies: 5 :: Views: 1198
I need a timing circuit with the said output below. You may say this is an ordinary monostable circuit. But this is probably not, the circuit will only change its output after a certain period of time after the user triggers the circuit.
Another difference is that the output is dependent on the users trigger, after the trigger is released (OFF)
Microcontrollers :: 08.10.2006 23:12 :: glenjoy :: Replies: 7 :: Views: 867
i have uploaded a corected version to
so check it out.
The idea is that you calculate the time on for the 555 timer i added to the time it takes to scan through the LED sequence and the time off to be the delay u want.
Hobby Circuits and Small Projects Problems :: 29.06.2007 18:37 :: ultrabrains :: Replies: 6 :: Views: 1308
You can use a 555 timer to implement the delay.
In the astable circuit, disconnect the DISCH pin, and make sure your button shorts the timing cap to ground when not pressed. Once you press the button, it should open its contact and the timing cycle will begin. Once the time has expired, the output will turn on and stay on (...)
Analog Circuit Design :: 04.07.2007 12:38 :: VVV :: Replies: 2 :: Views: 850
I wonder if it can be done with a two 555's wired as monostable??
Hobby Circuits and Small Projects Problems :: 23.02.2008 12:14 :: rx5 :: Replies: 8 :: Views: 2839
I think it?s a perfect job for something like the PICAXE-08 ..
Cutting story short, it?a 8-pin PIC based microcontroller with BASIC interpreter ..
Almost no external components are required, and if you stuff it up for the first time ? just change the code ..
Look, mate, the 555 is still good but in applications that require a little bit of ?in
Electronic Elementary Questions :: 16.07.2008 08:25 :: IanP :: Replies: 12 :: Views: 1374
Yes, it is possible, but you need more than one 555.
Can you describe the application a little better?
Analog Circuit Design :: 09.10.2008 12:27 :: VVV :: Replies: 4 :: Views: 842
Wondering how i might have diff. delays by using 2 diff. size resistors in my RC.
I know you can have 2 together in series but i was thinking of having one to provide a very short delay whenever the board starts up due to a power change, and another one that would occur whenever the restart was due to a reset button that pulls pin2 low on the
Analog Circuit Design :: 12.01.2009 12:39 :: vandyo :: Replies: 2 :: Views: 598
I think you can use a 555 with a relay.
Electronic Elementary Questions :: 18.02.2009 12:16 :: VVV :: Replies: 7 :: Views: 1348
Power-on delay can be realized in several ways, for example with the very popular 555-timer, but I would like to encourage you to use a small microcontroller, some times called the 555 of the new millennium, namely the PICAXE08 ..
You shouldn’t have problems in buying it in Australia (Altronics) ..
Analog Circuit Design :: 16.02.2010 09:07 :: IanP :: Replies: 3 :: Views: 677
For jobs like that you may consider PICAXE08 ..
Some times it is called the new millennium 555 ..
Not only you don’t need to worry about R or C, and triggering the 555-timer on power-on can cause some problems ..
Nothing like that with PICAXE, if you need to change time, or delay, (...)
Analog Circuit Design :: 20.02.2010 20:52 :: IanP :: Replies: 10 :: Views: 806
here is the App.
Unnafortunatelly, this document does´t bring informations about range of output current.
This tolerance could explain your imprecise result.
Concerning delay, it is su
Hobby Circuits and Small Projects Problems :: 20.12.2010 13:40 :: andre_teprom :: Replies: 14 :: Views: 4877
You can use a 555 timer in a monostable mode to get the desired effect. Check out this page, under monostable, and using the circuit modification mentioned in "Power-on reset or trigger" (cap in parallel with power switch)
555 timer circuits
The basics of why this works is detail
Electronic Elementary Questions :: 07.03.2011 21:41 :: enjunear :: Replies: 16 :: Views: 6925
I want to add a timer circuit to a led flashlight so after I press the 'on' switch it will shut off after a few minutes automatically
1. It has to be small
2. it works on 3 AAA cells possibly nimh so v~1.2*3=3.6V
3. no drainage during the many many hours when the light is off (either main switch off or timer switch off) so i don't d
Analog Circuit Design :: 10.03.2011 07:54 :: shalomw :: Replies: 4 :: Views: 1011
555 can be used as a 50% Duty cycle Generator, Astable Mutivibrator, Monostable Multivibrator and also Bistable Multivibrator.. Don't confuse with time and Frequency.. Frequency is nothing but Frequency = 1 / time... If your pulses need 50% duty cycle means then the formula for choosing Resistor and Capacitor value as per your frequency (...)
Electronic Elementary Questions :: 13.04.2011 12:44 :: kandhu26 :: Replies: 4 :: Views: 739
i am building a simple DC-AC inverter for my school project, i am stucked at how to use a 555 timer to generate control signals to control two MOSFET, which will output ON/OFF/OFF to one MOSFET and OFF/OFF/ON to the other MOSFET, is there a simple logic circuit to do the job? ideas?
Hobby Circuits and Small Projects Problems :: 08.08.2011 23:28 :: ful24 :: Replies: 18 :: Views: 1945
I'am new to this forum and know a little about electronics. I''m also thirteen.
I searched the forum for a similar project.Before posting here.But? Could not find any thing to what i need.
I build a astable 555 timer for clocking the time period of 10s appox
five secs (On) five secs (Off). Just to learn how the (...)
Professional Hardware and Electronics Design :: 13.10.2011 21:02 :: Ebonic :: Replies: 62 :: Views: 3524
I am using an TLC555C chip from Texas instrument to form a monostable timing circuit (see attachment). When simulated this circuit gives a delay of approximately 17s, in real tests using a 10uF ceramic capacitor the delay is approximately 12s and 18s with a 10uF aluminium electrolytic capacitor. Have anyone else experience that the (...)
Analog Circuit Design :: 21.12.2011 04:24 :: jdh_1984 :: Replies: 7 :: Views: 1017
Maybe you need to have a timer and delay using a LM555+CD4017 70183 johnson counter for your 6sec delay ?
Analog Circuit Design :: 04.03.2012 06:58 :: vimalkhanna :: Replies: 3 :: Views: 1277
Hi! I'm trying to design a digital weighing scale that would open a certain port when a certain weight is present as input. However, the weight ranges are too close to each other and gives an equivalent ADC output of like 10.111 and 10.555.. how do i consider the numbers after the decimal point to be read by the analog to digital converter. Please
Microcontrollers :: 17.05.2012 11:08 :: Thunderhorse312 :: Replies: 5 :: Views: 488
Yes it is possible, altough your 120 seconds won't be extremely accurate. You can expect to end up with about +-10% tolerance on your timing.
Electronic Elementary Questions :: 26.09.2012 07:01 :: not-a-moderator :: Replies: 3 :: Views: 567
Hi guys. I'm new here so a little back'ground. I'm an automotive mechanic with a background in automotive electronics. that being said I'm working on a project and while I do work on automotive components this goes a little deeper than I ever need to go. I need a component that I can momentarily trigger to energize a relay for 5 seconds. I hav
Electronic Elementary Questions :: 30.10.2012 00:06 :: newb12 :: Replies: 7 :: Views: 398
A 555 timer IC might do the job. It's one of the most popular and easy-to-use chips.
You would arrange it to trigger when it detects a drop in volt level.
The output goes high for 15 seconds, whether the switch is closed again quickly, or remains open.
The length of time delay is set by the 150 kOhm resistor and 100 (...)
Electronic Elementary Questions :: 20.12.2012 18:52 :: BradtheRad :: Replies: 1 :: Views: 234
For a first guess, have a look at 555 timer application notes. If you want zero current consumption in off-state, a different approach might be required, e.g. using CMOS logic ICs or transistors.
Hobby Circuits and Small Projects Problems :: 26.07.2013 05:42 :: FvM :: Replies: 34 :: Views: 914
Do you mean you need a delayed starter?
You could use a 555 timer and connect it's output to a transistor to power your LC circuit.
Analog Circuit Design :: 08.11.2005 23:45 :: Lord Loh. :: Replies: 5 :: Views: 704
Could any one provide me with code for detecting a pulse stream such as that from a 555 timer in astable mode. Here is something I came up with. A circuit attached to RA0 and RA1 detects movement. If there is no movement the is a stream of pulses at RA0 and RA1. If there is movement, the pulse stream stops. It measures the time (...)
Microcontrollers :: 07.12.2005 09:48 :: adigwe :: Replies: 0 :: Views: 521
Single capacitors quite often don't work well as delay circuits ..
Maybe you should consider the very popular 555 timer .. something similar to this:
Hobby Circuits and Small Projects Problems :: 13.08.2006 00:55 :: IanP :: Replies: 8 :: Views: 3216
use 555 as ramp generator, see datasheet NE 555
Professional Hardware and Electronics Design :: 18.02.2007 09:21 :: Kurniawan :: Replies: 5 :: Views: 2097
Using 555 wil be the best option as far as i know.. If u want to develop it from transistors,then build multivibrators(astable or monostable as you wish..) Refer some circuits through google search..
Using comparator is another option,but 555 is the best if u want to change the duty cycle.. 555 is very flexible ic..
Electronic Elementary Questions :: 01.08.2007 21:53 :: dineshbabumm :: Replies: 8 :: Views: 2387