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Schematics, Help Please Answered

Hello, I'm trying to create a simple timer that sets off a device after a set amount of time. I'm using a schematic from a basic electronics book that my grandfather had given me a few years ago. And it seems simple enough to the point where I can understand how it works. But I just can't seem to figure out how to actually put it down on a breadboard to even test it. So if you could possibly help me find out how to place this down on a breadboard to at least test, I thank you very very much. -The picture of the schematic should be below.

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caseyweed
caseyweed

12 years ago

What I really need is the stupid-man's explanation of the 555 timer. So I could actually understand how each of the other components interact and use each other. Would any of you know of a good site that may provide this?

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westfw
westfw

Reply 12 years ago

For this circuit, what happens is when you push S1, you trigger a flip-flop that both turns on the output (pin 3) and allows C1 (or C2) to start charging through R1. When the voltage on C1 reaches Vsup*(2/3), it resets the flip-flop, turning off the output and discharging the cap. A slightly different wiring will automatically retrigger the flip-flop when the cap voltage gets DOWN to Vsip*(1/3), resulting in an oscillator rather than a "one-shot" timer.

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caseyweed
caseyweed

12 years ago

Thanks I'll definitely do that. No, I only have Basic and Digital (Advanced) electronics. My grandfather passed away from brain cancer before he could teach me more. But he taught me what he could before he died.

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NachoMahma
NachoMahma

12 years ago

. Read a little further into the book (or maybe a little ahead of where you are). Mr. Mims is usually very good about explaining what's going on.
. Did your grandfather give you more than one book? If so, they may include Mr. Mims' book(let) on 555s.
. Enter "555" (minus the quotes) into the Search box at the top of the page or Googling 555 +tutorial turns up a lot of good info.

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caseyweed
caseyweed

12 years ago

Thanks a bunch! It is indeed one of Forrest Mim's books. It came with a module like kit along with another advanced digital electronics book. I'll look up some more pictures as well as read more into the book as well.

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Goodhart
Goodhart

Reply 12 years ago

Yes, finding out the "pin out" in other words, the location of the designated pin numbers, will help tremendously.

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NachoMahma
NachoMahma

12 years ago

. Is that from one of Forrest Mims' books?
. Plug your 555 into the breadboard, fairly close to one end of the board. On most breadboards, it will be straddling a "valley" in the middle of the board. Start adding your jumpers: from the hole next to pin 1 of the 555, jumper to ground (-6V, in this case), from pin 5 to a capacitor located elsewhere on the board (that why I recommended putting the 555 near one end) with one side of the cap stuck in the ground rail, &c.
. The numbers next to some of the components (eg, 46 & 47 next to the SPST/NO/MC switch) may indicate some numbering system on a particular breadboard.

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NachoMahma
NachoMahma

Reply 12 years ago

. PS: Google Images finds a lot of good pictures of breadboards so you can get an idea of how other ppl lay out the components.