What is the 555 timer schematics for 38kHz? - Page 1
Forum section: electronics / beginners

author: Dylon124
author_rank: Contributor
timestamp: October 07, 2013, 12:56:18 am
content: I need a 555 timer schematic for 38kHz. Can anyone help? I can never get it right.

author: c4757p
author_rank: Super Contributor
timestamp: October 07, 2013, 12:59:44 am
content: Quote from: Dylon124 on October 07, 2013, 12:56:18 amWell, what's your best try?

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: October 07, 2013, 01:10:59 am
content: That's the modulation frequency for remote control’s,Just search for light break detector

author: eendje
author_rank: Newbie
timestamp: October 07, 2013, 01:25:20 pm
content: Hi Dylan,use two 1,9 Khz resistors and a 10 nF cap will do...that will be about 38 Khz at 50 duty cycle..Regards,Bobps if you have an android phone you might usefull

author: Zero999
author_rank: Super Contributor
timestamp: October 07, 2013, 01:47:52 pm
content: Quote from: eendje on October 07, 2013, 01:25:20 pmLol, resistors are measured in Ohms not Hz.

author: zapta
author_rank: Super Contributor
timestamp: October 07, 2013, 04:07:51 pm
content: Try online 555 calculators, e.g. thishttp://www.ohmslawcalculator.com/555_astable.phpor thishttp://freespace.virgin.net/matt.waite/resource/handy/pinouts/555/

author: Wytnucls
author_rank: Super Contributor
timestamp: October 07, 2013, 04:29:40 pm
content: Try this set up:

author: Skimask
author_rank: Super Contributor
timestamp: October 07, 2013, 04:38:19 pm
content: Quote from: Dylon124 on October 07, 2013, 12:56:18 amAnother 5 post contest enter-er?

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: October 07, 2013, 05:50:53 pm
content: I noticed that there was a lot of new low count posts trying to get past the required minimum regarding the competition. Well there are, but assumed people were just joining to get into the comp.Then i thought I’d check somethingThis guy registered on 1st May according to his profile, so he as been around and not just registered.Perhaps Dave should put a registered with minimum positive posts before competition was announced clause.

author: Wytnucls
author_rank: Super Contributor
timestamp: October 07, 2013, 05:53:27 pm
content: What for? The idea behind the competition is to bring in new members, not to reward long term members.

author: andtfoot
author_rank: Unknown
timestamp: October 07, 2013, 05:57:39 pm
content: Quote from: eendje on October 07, 2013, 01:25:20 pmFixedI've also found this calculator that works the other direction; put in the frequency and it spits out standard values to get it close. No control over the duty cycle though (although it does tell you the result). There are heaps out there, so there is probably a better somewhere.http://houseofjeff.com/555-timer-oscillator-frequency-calculator/It's probably good for a starting point. You can then use the other calculators mentioned before to tweak the values.

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: October 07, 2013, 06:02:53 pm
content: Quote from: Wytnucls on October 07, 2013, 05:53:27 pmWell, looking at the stats, a competition isn’t needed; April 2013 brought in 11,804 new members. Anybody know why that was.Up to now, this month there has only been 400 new members.Just a thought

author: geraldjhg
author_rank: Regular Contributor
timestamp: October 14, 2013, 07:37:28 pm
content: try TI or NS or ON555s are not easy to generate 50% duty cyclebut any pdf about them will show you how to

author: DavidDLC
author_rank: Frequent Contributor
timestamp: October 14, 2013, 07:44:10 pm
content: Quote from: eendje on October 07, 2013, 01:25:20 pmGive fish to a man and he will eat for one day, teach him how to fish and he will eat for the rest of his life.Instead of giving him values, teach him how to calculate them...

author: AlfBaz
author_rank: Super Contributor
timestamp: October 16, 2013, 06:01:42 am
content: Quote from: Mr Smiley on October 07, 2013, 06:02:53 pmcan't help but feel it would have been this massively popular threadhttps://www.eevblog.com/forum/chat/hacking-nvidia-cards-into-their-professional-counterparts/

author: robbag
author_rank: Contributor
timestamp: October 16, 2013, 10:57:22 am
content: Why do people get so upset with new joiners and minimum posters? It's not all about the competition for some. You were all new at one stage the completion is just a bonus.No point contributing to the discussions if your view has already been stated by someone else, unless you like to read your own writing.

author: oaliey
author_rank: Contributor
timestamp: October 16, 2013, 01:58:16 pm
content: I admit I was pushed over the edge to register because of the competition, however am unlikely to enter it even if I get to 5 posts before it closes. The reason I registered was however because I saw something someone was selling that I was interested in, had it not been for the competition I wouldn't have checked the forum out.Anyway it's late and I don't feel like giving a quick 555 tutorial right now, maybe tomorrow? This does sound like a homework question and if so you should really show what attempts you have already made so instead of just giving answers you can learn how to solve the problem yourself. Now I recommend reading through a datasheet for the 555 timer.Here is one from TI:LM555NE555and fairchild:LM555In there you will find example circuits and equations. The fairchild datasheet has better descriptions on how each circuit operates.

author: Rigby
author_rank: Super Contributor
timestamp: October 16, 2013, 02:43:29 pm
content: Quote from: DavidDLC on October 14, 2013, 07:44:10 pmGive a man a fish and you feed him for a day. Don’t teach a man to fish, and you feed yourself. He’s a grown man. Fishing’s not that hard.

author: madshaman
author_rank: Frequent Contributor
timestamp: October 16, 2013, 03:28:45 pm
content: Sell someone a fish and not teach them and you have a customer for life? /evil

author: divelectservices
author_rank: Contributor
timestamp: October 16, 2013, 04:25:59 pm
content: Build a man a fire and you warm him for a day... Set a man on fire and you warm him for the rest of his life!

author: Skaface
author_rank: Contributor
timestamp: October 17, 2013, 05:08:23 am
content: who needs to know formulas these dayshttp://houseofjeff.com/555-timer-oscillator-frequency-calculator/

author: madshaman
author_rank: Frequent Contributor
timestamp: October 17, 2013, 11:58:30 am
content: Formulas? We don't even need first principals:www.google.com