Hi all, i asked a friend of mine to make a circuit for leds with the following parameters: 4 leds; each activated every second in a loop after turning device on; using 9v battery; 1.5v Input voltage. After a while he said he done the following http://img261.echo.cx/my.php?image=thingy3bb.png Can anyone pls tell me if that circuit is correct for those requirements i mentioned above? thank you in advance
When I first clicked on the link and viewed the picture, the words automatically came to my mind, "It looks like a microcontroller... it is one." The schematic looks correct to me, pins 10 and 20 are for power, make sure to include capacitor(s) for stability. Edit: Amtel is Atmel
Use a cd4017 and a 555 timer. I built one in about 5 minutes the other day, to test as a proof of concept for a larger project. As for the schematic, With an atmel processor, you will have to program it, and that requires a programmer, knowledge of how to program, etc... Essentially, that schematic is of a circut that people use when learning to program small µCPUs. I'll knock together a schematic later. How precise does the 1 second interval have to be. *edit* Here ya Go: You decide the values fo the LED resistors. 1 k works fine. V+ is flexible, as you can adjust the cycle time with the potentiometer. Not sure how precise the 555 circut values are, as i just guessed most of them. It'll work fine though. 555 timers are easy enough to work with though.
And are you able to program the µCPU (or is he prepared to)? Unless you want very accurate timing, a 555 + 4017 would do the job cheaper. *wolfe beats me while I'm drawing pretty pictures...
Hah! Parallell Posts ! Should have remembered to only use 1 LED resistor. * Fixed It * What schematic program do you use, cpemma? I just re-edited my older post after drawing the schematic
It's Livewire, buggy but nice for drawings. How come your image has .txt extension, can't view it full size? He only wants 4 leds, resetting the 5th output re-starts the cycle. 1k/68k/10uF is close to 1Hz, but with loose tolerance caps a 100k trimpot lets you tweak to fit. Calculator here, use the astable.
The txt extension let's me host it on Geocities. I still have an account, from when i signed up (i was twelve, i think), and it's convenient. They block things like .jpg, and .gif from being accessed alone, but can't block .txt, as it is a valid file type. The browser doesn't seem to mind. Cool! fancy calc! I just knocked about with the formula given in the datasheet. I wasn't thinking much when i drew the schematic (late at night, over here), and i got the flu. This way he gets to see his options, and how easy it would be to use 10.
