controlling the speed of a 555 (for vanishing point)

[ugly_guitar_guy]

Ok, I've managed to get this schem breadboarded and working to be the engine of my vanishing point wah:



Now, I know that I can put a pot in where the resistor is and control the clock speed, but it's still far too fast. What values can I use for the cap and pot to be able to have a wider range of speed (very slow to super fast)?

[JKowalski]

Use a larger cap, maybe 1uF? Just keep experimenting. If it's breadboarded that should be easy 

[ugly_guitar_guy]

Thanks, I'll try that and see what comes of it!

Now, I just tried adding Andrew's 4/6/8 mod into the circuit:



but what happens is instead of it stopping at 4 or 6 and restarting at 1, it skips 4 or 6 and keeps cycling through. Also, the reset switch (momentary) doesn't restart at 1, it just cuts out the sequence as long as i have the button pushed, and comes back in wherever it would be if i had never pushed the button. Ideas?

(sorry for being such a pain in the ass about this circuit guys. I'm learning as I go and I'm determined to get it working!) Thanks!

[ugly_guitar_guy]

Thanks, I'll try that and see what comes of it!

Now, I just tried adding Andrew's 4/6/8 mod into the circuit:



but what happens is instead of it stopping at 4 or 6 and restarting at 1, it skips 4 or 6 and keeps cycling through. Also, the reset switch (momentary) doesn't restart at 1, it just cuts out the sequence as long as i have the button pushed, and comes back in wherever it would be if i had never pushed the button. Ideas?

(sorry for being such a pain in the ass about this circuit guys. I'm learning as I go and I'm determined to get it working!) Thanks!

Ok, I figured it out. I had the inhibit pin still connected to the reset directly. I pulled that trace and it's good to go!! Now I just need some more caps so that I can experiment with the speed... :S

[frequencycentral]

http://electro-music.com/forum/topic-36133.html

[ugly_guitar_guy]

http://electro-music.com/forum/topic-36133.html

Very cool link, thanks. Now that I understand the technology better I might try to build a 16 step down the road to get really MUSE-ey with this.

Also, the 1uF cap worked great. With a 1M pot it gets a huge sweep of speed (to the point that the ic can't keep up with it if i go top speed). Ok, now on to my next question which I'll create a new topic for...