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


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


I need help to find a plan for a elapse time timer. The kind that will tell the time from one input and the second.?

I am setting up a race course for gravity racer.  You can not see the top or start from the bottom.  An electric clock will stop some of the arguments.  Thank you

Question by jds311   |  last reply


Build a circuit which gives a signal for 5 seconds once in every two hours. What components would you recommend?

I need a very low power signal and i need it for a duration of 5 seconds once in every two hours. If a resistance pot could be included to vary these durations(5 seconds and two hours), that would be great. There should be one master switch to the circuit which will switch on/ switch off the circuit.

Question by Nikhit   |  last reply


special timer?

How do i make a timer that would have a big button to start the timer, then a touch sensor that stops it. and then where do i get a big timer clock at?

Question by ClemensY290 


wrist timer

Can anyone build me a wrist countdown timer? PM for details

Topic by gio_13   |  last reply


Meditation Timer

I'd like to modify a simple egg timer for meditation.  My current timer makes loud harsh staccato beeps.  I'd really like a timer that made something that sounds like a long slow deep bell when the time is up. I have no idea how to do this but I'm guessing someone does and can do it for less than the $100 ones they sell in the glossy Buddhist catalogs.  Any help would be great mattcadorette@hotmail.com

Topic by mcadorette   |  last reply


Electronic timer

I want to make a timer that sounds an alarm every three minutes, pluss one for setting a seperate alarm for 1 minute.  It is to be used during cpr, (treatment cycles are 3 minutes. 1 minute from shock to circulation check.  Can anybody help me??

Topic by leidulv   |  last reply


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


Circuit Timer

I would like to be able to set a time, small like .5 seconds, and be able to power a 12v circuit for that amount of time, any ideas? 

Topic by ReconIII   |  last reply


Request for timer

I would like to make a timer circuit for one or two digicams. Something which would press the shutter button at a desired interval, like from 30 sec to several minutes, to make high resolution timelapses. (2 cameras for stereo, or visual - infrared) I know this should be easy, a simple circuit with relays, but having no knowledge of electronics it would help to have it pointed out step by step)

Topic by BobS   |  last reply


Relay Timer

I am currently engaged in a project where i need to create a count down timer relay controller. i was thinking of using a digital alarm clock as part of my goal is to have the display visually counting down, but i don't know of any that have a count down feature. i want the timer to power a relay to turn a string of IR emitters on for several seconds. i have a digital kitchen timer that counts down, but im not sure if it will work. i would like to use the power to the buzzer to activate the relay but there is no stable current there, it only Emits several beeps in quick succession(when i meter it, it comes out to about . volts). this is why the alarm clock would be better. i was hoping to use an electromechanical relay but i don't think it will work. does anyone know of another relay that will trigger with this kind of input?

Topic by gedion4000   |  last reply


Relay timer?

I asked this question in forums before i knew about this so sorry for the copy. i hope someone can answer this here. i am currently engaged in a project where i need to create a count down timer relay controller. i was thinking of using a digital alarm clock as part of my goal is to have the display visually counting down, but i don't know of any that have a count down feature. i want the timer to power a relay to turn a string of IR emitters on for several seconds. i have a digital kitchen timer that counts down, but im not sure if it will work. i would like to use the power to the buzzer to activate the relay but there is no stable current there, it only Emits several beeps in quick succession(when i meter it, it comes out to about . volts). this is why the alarm clock would be better. i was hoping to use an electromechanical relay but i don't think it will work. does anyone know of another relay that will trigger with this kind of input?

Question by gedion4000   |  last reply


Switch Timer

Good day, Please i have 2 bulbs/leds, one is green and the other is red. I want to put a time switch between them so that after 10 minutes the red switch off and the green lights up and vice versa till i switch it off. So do you know of any switch that i can use for that purpose, that will operate under 12v, like 5v. Please thanks

Topic by Don Amada   |  last reply


Countdown Timer

Hey guys, first forum post. I have just gotten into the electronics field, and I have made a few circuits that I have read schematics from. There's something I want to make, and it's a countdown timer. This is want I want it to have: Be able to count down from at least 15 seconds and be able to change the amount of time Have some 7 segment displays Use the least amount of voltage possible (ie: not need to use the mains or some 12 volt power supply, id rather use a couple of AA's) Have a relay capable of turning on or off a light. And to be as simple as possible. Because I am rather new to this I would rather a schematic, rather than just some help on which components I need to use, because I don't know where they need to solder to where.  Thanks

Topic by ryanlg   |  last reply


Arduino with timer? Answered

I'm not very good at coding so I want to come to you guys again. I need help with a sketch or code that allows me to have three inputs and one output. When one button is pressed, that Arduion pulls the output high for an amount of time dependent on which button is pressed. These times are 3 seconds, eight seconds, and twelve seconds. The output will be connected to a small relay, which I already know how to do. If I could get any help that would be great. Thanks.

Question by mrmerino   |  last reply


Timer Circuit

I found this simple circiut on jamesyawn.com, and was wondering if and how to change it so that it could time in the minutes, longer than it does already. I don't know anything about electronics, aside from soldering, and basic connections, so try to give a simple-ish answer. I also wondered about what transistor to use (like a radioshack part number). The circuit I was talking about is under "discrete timers".(update, more questions)What kind of timing (like how many seconds) would I get with this?Using the same stuff shown on the schematic?Also, how do I pick a transistor?Are they interchangeable? What specs should I be looking for? If this seems like too much, could someone give me a link to a site that would be willing to help with (very) beginning electronics?AND, how would you recommend making the transfer schematics for home-etched circuit boards? I can't get the component spacing right.

Topic by John Smith   |  last reply


Are there any common timers that are programmable to the second? (my sprinkler timer is programmable only to the minute)

We are using a sprinkler timer to automate the opening and closing of a ball valve by linear actuator. The problem is the sprinkler timer is only programmable to the minute, so it opens, lets water flow for a minute, and then closes. This wastes water as we only need to empy the tank for 10-ish seconds. Any timers that are programmable to the second?

Question by paulpaulpaulpaul   |  last reply


How is a 555 12V delay relay timer wired?

I purchased several simple 1-channel relay timers (single pot), followed online videos to use but I could not get them to function properly. Can anyone tell me, in clear detail, how to connect/wire them. I also purchased several other types of relay timers (double pot), much like the Vellman MK111 interval timer, these worked fine. Clearly I'm doing something wrong.                   cgc210

Question by cgc   |  last reply


I was wondering how do I connect a dimmer switch to a 24 hour programmable timer for a faux window. Answered

I was wondering how do I connect a dimmer switch to a 24 hour programmable timer for a faux window. I want it to look as real as possible. So I am looking for sunset and sunrise. Any help would be great! Thank you?

Question by Claypoolgal   |  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


First I'm still a newbie at electronics. I know there are schematics for the "annoying cricket" out there.

Is there a schematic or explanation telling me how to make the device give a double chirp then silent for a seond before another double chirp, turning off in the light and then back on in the dark?

Question by OnCrowsWings   |  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 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


Dual timer switch

Is there a commercial dual timer switch that the first timer can be set for longer duration like hourly or half hourly and then switch on another timer that run in seconds. Or is there a DIY solution? Eg. Turning on a water sprayer every 2 hours for 10 seconds. I need a timer that run from the mains.

Topic by TanJ21   |  last reply


advice about timer?

I need cheap small timer to use in my device ( voltage protector) to use in control of warranty of 3 months, this timer will connect to led and when the time is finish (3 month of real working) the led will off, this timer should calculate the time of electricity working only ( if electricity cut off the timer not calculate the time when there is no electricity)  the timer continue calculate the time of working only is case of electricity is exist. when the total time of electricity on (exist) reach 3 months the timer will cut off the power on the led so will turn off the led

Question by rubellamarket   |  last reply


Electronic timer circuit.

I have a 9vdc supplying 3ma constant current. I wish to switch polarity automatically every 5 minutes with a timer. How can I do that simply?

Question by rhhince 


Computer controlled timer

I am building an indoor hydroponics room to grow herbs and tomatoes year round. I would like to be able to control the lighting and the water pumps with my computer. Any ideas? Thanks!

Topic by InsaneLunatic   |  last reply


240 volt timer ?

Hi all I have a 240v fog machine makes fog like a disco I wish to run it on a timer. For an outside dragon smoke display. I can easily time it purely off /on with a basic 24 hour  household socket cheap timer MY PROBLEM The fog machine after getting power needs a press of a button to activate it. I need a circuit / timer  so  that when it gets 240v power can then "press the button "ie activate I bought a hi tech machine to try  but it loses it's memory setting when timed out on  240v. I need something that keeps its timer cycle intact. Maybe an expert out there can help? Happy to modify something etc. Nick Tasmania

Question by tassie2   |  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


Microwave Timer project....

I was wondering if anyone could help me figure out the proper way to connect a 5V battery power source to this microwave timer (pictured) I read this post- specifically the comments, but am worried I might fry the board if I do it wrong and with a 50/50 shot I'd like to ask the experts first. I've provided pictures below. Thanks for any help you can offer.https://www.instructables.com/id/Digital-timer-for-any-electrical-appliance/?ALLSTEPS

Topic by mrshow555   |  last reply


Tiny timer with display

Hi I want to make a timer - a very small one - for using in school, for cookling and so on... It needs to have a display with at least four digits, five buttons(reset, on/off, start/stop, minutes and hours). I'm planning on powering it by a CR2032, or another button-sized battery. Does anyone have schematics or circuits I could have a look at? In advance, thank you:)

Topic by simo9836   |  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


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


Timer Mod question

Anyone know how or if it's even possible to mod a countdown timer like this one:http://www.goldmine-elec-products.com/prodinfo.asp?number=G15871to have an led segment display like this: http://www.allelectronics.com/images/gold/full/SDA-801.jpgwould i just need to take off the old time and solder the segments of the new display accordingly?

Topic by mrshow555   |  last reply


Mechanism for mechanical timer

Hello everyone, My wife and I both feed the dog, but we're never sure whether the other's already done it or not.  (the food disappears pretty quickly)  I'd like to build a track with a slider that takes about 10 hours to slide from 'fed' at the top to 'not fed', and make it so that the slider is easy to slide back to the top. What immediately comes to mind is a counter weight escapement mechanism, but I though I'd hit up the brain trust to make sure there wasn't a simpler way to pull this off.  (I could also envision a timer chip hooked to a mechanical release, but I'd prefer to stay wholly mechanical for this one.) Many thanks!

Topic by oldmicah 


Arduino timer with photoresistors

For a science project i need to be able to measure the velocity of an object, to do this i planned to use arduino to measure the time between the object breaking a laser pointers beam onto a photoresistor and it breaking a second similar beam/photoresistor a set distance away. Alas ive had some trouble with the photoresistor side of things, can anyone describe how to properly implement a photoresistor? such as which ports i could connect it to and how to read when the beam would be broken.

Topic by shabaki   |  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


Arudino countdown timer? Answered

I'm looking to make a countdown timer for my local card shop for games of Magic (nerdy, I know). However, I think I jumped the gun, as I have no idea how to do this.  My plan is to us an arduino nano/barebone arduino as the brains to this, make my own 4 digit 7 segment display, and have give it a programmable time (nothing over 50 minutes) along with a start, stop, and reset button.  I've done quite a bit of looking, and have yet to find something that matches my needs or comes close to it so I can reverse engineer the code a bit. Any sort of help on this would be greatly appreciated!  Should also mention I'm a tad bit of a newbie to C. I know enough to know where i need to look for a good chunk of things, but thats for simple things like "make this LED blink according to these random inputs"

Question by DoctorWoo   |  last reply


Moon light timer

I would like to build a led light that switches on and off with the moon. On when the moon rises and off when the moon sets. Would also like no leds on at new moon and an additional led comes on until full moon is reached. The process then reverses an an led goes off until new moon with no leds on. I would also love the light output to be 4150k the colour of moon light and about 1 lumen at 1metre distance.

Topic by Ausie Steam   |  last reply


timer-control of PC?

I'm trying to find a simple way to turn on my PC multiple times each day. I use the BIOS to turn it on now to record radio streams. I'd like something external to the PC, and something I could use to set several On Times each day. I don't know where to start. Should I attempt adding a relay to parallel the PC's power switch and then activate the relay? Should I attempt to build Rube Goldberg mechanism to mechanically activate PC's power switch? Wake-On-Lan doesn't seem to be the answer as how would I reliably send signal while I sleep? Even if you don't know of something specific, I'd be interested in where to look or approaches to investigate. Thanks, Scott

Topic by tscottme   |  last reply


A visual timer for kids

I would like help figuring out how to make this special type of clock.   I need some for my daughter, but don't want to shell out the $30 plus dollars for each one.   It is basically counting down time in a visual way for children who are too young to understand numbers counting down. I know there are computer based ones online, but it is not always convenient to have the computer on. Thanks for any help! Karl

Topic by karling   |  last reply


A visual timer for kids

I would like help figuring out how to make this special type of clock . I need some for my daughter, but don't want to shell out the $30 plus dollars for each one. It is basically counting down time in a visual way for children who are too young to understand numbers counting down. I know there are computer based ones online, but it is not always convenient to have the computer on. Thanks for any help! Karl

Topic by karling   |  last reply


How can i get a 12v motor to automatically reverse polarity or direction by a adjustable timer ???

I have a machine that i built for hunting that swims  duckdecoys back an forth that mimics a live group of ducks and would like to control it by an adjustable timer to automatically reverse the direction of the motor  instead of having to hit a switch back an forth.Heres what i need exactly a timer that is adjustable by a knob that will switch direction of motor after a certain time an adjustable speed control by knob for the motor to speed up an slow down the motor an a on/off switch to turn the system on an off if someone could help me with a parts list and a schematic of how it all goes im shure i can figure it out

Question by frankswamper   |  last reply


Tired of dumping dehumidifier... Float switch, submersible pump, and a timer?

I have a small dehumidifier with a removable tank that has to be emptied far too often.   It has an integrated float switch in the tank that shuts down once full, but if you neglect to dump it, the basement gets way too muggy. I would like to put in a submersible pump (like this) that is activated by a simple mechanical float switch.  Once activated, I only want the pump to run for a set amount of time, in order to keep the pump from pumping all the water out and running the pump dry.  I thought about this timer, which has a minimum interval of one minute.  One to two minutes of pumping would be about right for the tank size, depending on the pump flow rate and where the float switch was set to initiate the pump. I had originally looked at a Kerick Valve float switch, but this will only let enough water drain out to lower the float and close the valve.  This will essentially just trickle out. Any ideas on this? I don't want to drill a hole in the tank and just run a drain tube... though I considered it.  Part of the reason is that I wanted to avoid just letting it trickle out.  And I also felt like I wanted to tinker just a little.  :)

Question by jmgustin   |  last reply


Using a microwave oven's timer as the mains timer switch?

I have a timer switch from an old dead microwave oven. Can I use it as the mains timer switch? If yes, how do I connect it. The timer looks exactly like what is shown in the following picture: http://hackadaycom.files.wordpress.com/2013/09/mads-microwave-teardown1.jpg (The picture was not taken by me. It is from an article on useful things that can be harvested from  dead microwave oven.) Also, if possible, please mention the functions of various pins or give a link to an explanation.

Question by raftor   |  last reply


Hi, Are there any known screw-in compact flouresant bulbs that will work with an electronic timer?

I have an electronic wall switch timer, I believe the brand is intermatic, if I attempted to use a compact flouresant bulb, it does'nt work properly. Is there a CFL made to work w/ my timer, or is there a special timer made to work w/ these type of bulbs? Thanks

Question by nyman58   |  last reply


I want an alarm to go off if the freezer door is open for 5 minutes or more.?

Our freezer door keeps getting left open, so I want to install an alarm that will go off if it stays open for 5 minutes or more.  I don't just want an open door alarm, than would be annoying when loading/unloading the freezer. One that would shock the offending child would be an added bonus but not needed.

Question by mark84gti1   |  last reply


what's going on with my LED dimmer circuit? Answered

I'm making a resin block lighting thing for my dorm room, but the lights are too bright to look directly at (and it's meant to be looked at). I decided to make a 555 dimmer circuit, and I used these plans. http://www.555-timer-circuits.com/led-dimmer.html when I built it, however, the LED stayed off. I couldn't figure out what was going on until I touched the two diodes in the circuit and noticed that the small current leaking through my skin caused the LED to blink slowly. I turned one of the diodes around, and lo and behold, the dimmer worked as expected. so what I want to know is: what was the purpose of the diodes in the original diagram? was the positioning of the diodes just an error in the design? should I run with what I have now (since it works), or do something different?

Question by codongolev   |  last reply


Auto egg turner motor. What motor do I need for my incubator?

I built an incubator from a redundant wine cooler but the motor wasn't up to the job. I had underestimated the total load and stripped the gears in the gearbox. Can someone tell me in very basic terms what I need to change and where to look for them? Also, the top connection needs to be a ball and socket type affair (not very smooth at the moment). Where do you buy components like that? Thanks. Paul http://www.backyardchickens.com/web/viewblog.php?id=33362

Question by toxo   |  last reply