What is the 555 timer schematics for 38kHz?

[Dylon124]

I need a 555 timer schematic for 38kHz. Can anyone help? I can never get it right.

[c4757p]

I can never get it right.

Well, what's your best try?

[Mr Smiley]

That's the modulation frequency for remote control’s,

Just search for light break detector

 

[eendje]

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,

Bob

ps if you have an android phone you might usefull

[Zero999]

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,

Bob

ps if you have an android phone you might usefull

Lol, resistors are measured in Ohms not Hz.

[zapta]

Try online 555 calculators, e.g. this   http://www.ohmslawcalculator.com/555_astable.php or this http://freespace.virgin.net/matt.waite/resource/handy/pinouts/555/

[Wytnucls]

Try this set up:

[Skimask]

I need a 555 timer schematic for 38kHz. Can anyone help? I can never get it right.

Another 5 post contest enter-er?

[Mr Smiley]

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 something 

This 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. 

 

[Wytnucls]

What for? The idea behind the competition is to bring in new members, not to reward long term members.

[andtfoot]

Hi Dylan,

use two 1,9k resistors and a 10 nF cap will do...

that will be about 25.316KHz at 66.67% duty cycle..

Regards,

Bob

ps if you have an android phone you might usefull

Fixed 

I'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.

[Mr Smiley]

What for? The idea behind the competition is to bring in new members, not to reward long term members.

Well, 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 

 

[geraldjhg]

try TI or NS or ON
555s are not easy to generate 50% duty cycle
but any pdf about them will show you how to

[DavidDLC]

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,

Bob

ps if you have an android phone you might usefull

Give 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...

[AlfBaz]

What for? The idea behind the competition is to bring in new members, not to reward long term members.

Well, 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 

 

can't help but feel it would have been this massively popular thread
https://www.eevblog.com/forum/chat/hacking-nvidia-cards-into-their-professional-counterparts/

[robbag]

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.

[oaliey]

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: LM555
                                NE555
and fairchild: LM555

In there you will find example circuits and equations. The fairchild datasheet has better descriptions on how each circuit operates.

[Rigby]

Give 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...

Give 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.

[madshaman]

Sell someone a fish and not teach them and you have a customer for life?  /evil

[divelectservices]

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! 

[Skaface]

who needs to know formulas these days http://houseofjeff.com/555-timer-oscillator-frequency-calculator/

[madshaman]

Formulas?  We don't even need first principals: www.google.com