Jump to content
Electronics-Lab.com Community

How do I produce this signal? [All Better!]

Recommended Posts

The amplitude is unknown, it simply needs to click a small reed relay, I don't belive this will be a problem.

It is a continues pulse, where it goes high for .5 seconds, low for 1 second, then high again for .5 seconds, then repeats every 4seconds.

I should have said that in the first place!  :-[

Link to comment
Share on other sites

If a 5 volt amplitude is desirable, you could use a clock circuit and some logic or clock circuit with 4017s where you choose the output pins that would give you the correct timing. For a more accurate source, you could use a microcontroller. Turn the port pin on, start a 500 millisecond count, turn it off, start a 1 second count, turn it on, start a 500 millisecond count, turn it off, start a 4 second count, and loop (repeat). Such a circuit would only require a cheap micro, a clean 5 volt source, and a resonator.


Link to comment
Share on other sites

"clock circuit and some logic or clock circuit with 4017s"
Could you expand a little bit on these two?
Especially the 4017s. I am familluar with those and have access to many of them.

I tried this circuit with 555 timers and got close, but it is so ridiculous! In fact, I had to take it apart and add 2 more times to it, then I probably would have needed another after that! I don't believe this circuit should require five 555 ICs!

So, yes, please, expand.


Link to comment
Share on other sites

Have you made one of the blinky light projects with the 4017? If so, you know that the clock frequency causes each output to fire off in a controlled sequence. Thus, if your clock signal causes each of the LEDs to blink at every 0.5 seconds, you could select the pins you want for a pulse every 0.5 seconds, 1.0 seconds, 1.5 seconds, etc. Of course, you are not lighting LEDs, but are using the outputs for pulses, instead. For example, output pins 1 and 4 would probably give you a pattern like your timing diagram and you would need a 12th sequence to re-trigger the first again at the correct timing. To get a 12th sequence, you will have to cascade 2 4017s. You basically have a 0.5 second time base and you can choose which increments you want to use until it loops back and starts over again.


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...