Generator  from a 555 - Page 1
Forum section: electronics / beginners

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 17, 2013, 09:03:52 pm
content: Hello , I made a generator with a 555 today, and I'll post a picture sometime tomorrow the pattern is very similar to this exept the vertical isn't straight like this one it's more curved, my daughters call it shark tooth wave, I may invented my own signal wave.

author: Stonent
author_rank: Super Contributor
timestamp: August 17, 2013, 10:29:15 pm
content: I think I know the wave you're talking about, I call it a shark wave, or when I see it I say the wave is shark finning.When Afrotech draws too much power from his power supply it does it. (about 5 or 6 minutes in).If you half wave rectify a sinewave, smooth it with a capacitor and put a load on it, it will do that.

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 18, 2013, 05:38:32 am
content: Quote from: Stonent on August 17, 2013, 10:41:06 pmYes this is it

author: Stonent
author_rank: Super Contributor
timestamp: August 18, 2013, 06:14:10 am
content: The rise is the sine wave but the fall is the discharge of the capacitor.

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 18, 2013, 07:15:09 am
content: This is my actual wave taken this morning.

author: G7PSK
author_rank: Super Contributor
timestamp: August 18, 2013, 09:46:39 am
content: What's the circuit, and whats the frequency, looks like the cap is taking to long to charge, but then I am most likely wrong on that.Edit. Velleman used to make a 555 kit that produced that wave form as one of four that the circuit made, they called an "integrator" wave.

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 18, 2013, 08:40:44 pm
content: Quote from: G7PSK on August 18, 2013, 09:46:39 am555 Generator circuit, freq was 42hz approx cap 3.3uf

author: MrAureliusR
author_rank: Unknown
timestamp: August 19, 2013, 06:30:15 am
content: From my experience with 555s, yeah 3.3uF would take a bit too long to charge.

author: G7PSK
author_rank: Super Contributor
timestamp: August 19, 2013, 07:07:06 am
content: For that frequency the capacitor should be in the region of 0.1 uf.

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 19, 2013, 08:20:43 am
content: Quote from: G7PSK on August 19, 2013, 07:07:06 am, Ok I'll have a play with it, I think it goes up to 4.6 khz, I may also try , putting the caps on a rotary switch, and then maybe I can change the response for each defined frequency range.

author: G7PSK
author_rank: Super Contributor
timestamp: August 19, 2013, 08:44:15 am
content: This graph might help.

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 19, 2013, 08:50:43 am
content: Quote from: G7PSK on August 19, 2013, 08:44:15 amthank you

author: dentaku
author_rank: Frequent Contributor
timestamp: August 19, 2013, 11:32:17 am
content: Since I'm interested in making interesting sounds I like that waveform. It's a sort of saw but not quite. I see it allot when I sweep into lower frequencies. You're just seeing the time it takes for the capacitor to charge and discharge which is not linear since it's curving.I triangle-ish wave that looks like this at higher frequenciesturns into this at lower frequenciesQuote from: M0BSW on August 18, 2013, 07:15:09 am

author: M0BSW
author_rank: Frequent Contributor
timestamp: August 19, 2013, 02:52:31 pm
content: Quote from: dentaku on August 19, 2013, 11:32:17 amYes all these different waves are fasinating, I've become attached to this one , but I don't see how I could you it in a electronics situation , unlike square triangle, and sine. Think i'm going to leave it as is though.