Hello, i just recently got a reference design to A "Flashing LED" circuit, which is centered around the application of a 555timer (NE555).

At this point I would like to add more LED's and change the rate of blinking. Would like to know if anybody has links that are overviews to understanding and applying the 555timer. Thanks.

Also, thinking a little beyond the 555timer (I'm kinda new to electronics) what would be a chip that could allow me to manipulate networks connected to the 555timer. Like for instance, changing the capacitance attached to pin 2 of the 555 can adjust thee rate of the blinking, I'm envisioning that a transistor could be placed there and could help switch between different capacitance networks, allowing me to change the rate of blinking in real--time, or better yet, I would be able to create individual "modes" of blinking. I figure I would need some other type of IC to manage the transistors I place around the 55 timer...

 

Hello,

Have a look here:
...LEDs, 555s, Flashers, and Light Chasers

This is one of the threads from Wendy.
She made an index of all her submissions:
Wendy's Index

Bertus

 

Yup! Wendy's Index. It's where I got my 555 inspiration from for my project.

 

Would like to know if anybody has links that are overviews to understanding and applying the 555timer.

Learn how the timer works and you won't need to depend on someone else for ideas. Page 7 of the attached datasheet has one of the most detailed explanations I've seen (in a datasheet).

 

Might try a 4017, 74HC4017 with isolating diodes on outputs to switch timing R's , or any method to switch voltages, maybe counter with 4 line to 10 decoded outputs.
Or 4066, 74HC4066, digital- analog switch to switch R's or C's.

 

Here's one of my older 555 circuits. It consists of the usual stuff along with a 4PST switch that can switch in and out different capacitors. And there's an IC carrier that I can throw any capacitor I like into the circuit to achieve even more time frequencies. I could throw a 10 pF cap into the chip carrier and turn all the other capacitors off. I can throw multiple capacitors into the timing to achieve still more timing possibilities. With the 2n3906 transistor I'm not limited to the control voltage. I can control any voltage the 3906 can handle.

[edit] My resistor numbering convention comes from precision resistors that don't have color codes, they have numbers. Just remember the last number is the multiplier. For instance, a 104 is a 1, a 0 and 4 zeros (100,000 Ω). Not the most common convention for resistor coding in through hole components, but I relate to it quickly. {end edit}

[edit #2] The diode (1n4001) is a channeling diode. The charge rate is through R2 and the discharge rate is through R1. {end edit}

Here, have a look: