Newbie Question: Why 5V not 9V, and why a regulator?

RingMad

First of all, HELLO electro-music People and especially Lunetta-ers! I've been lurking on these forums several months, learning lots of things... I've built a couple of boxes based on 555's and 4093's, and then fell in love with the Lunetta style.

So now I am starting to mess around with more of the 40XX's, familiarizing myself with their workings whilst I decide if I want to go with a perfboard or panel design, and finding the right parts for it.

Anyway, my questions are: why is 5V recommended and not 9V? I see on datasheets that most can handle up to 15V and sometimes even more.

And: why use a 7805 voltage regulator?

I've used the "sag" or "voltage starve" technique before on a 4093 for example and I like the results. So a little voltage variation can add interest, no? A good way to add a bit of randomness?

Thanks for all the inspiring work!
James.

rich decibels · Posted: Sun Jan 23, 2011 7:12 pm Post subject:

Hi Ringmad, welcome to the forum! I don't think there is any 'ideal' voltage for this stuff, anything between 3 and 15volts will give good results. Usually when people specify a given voltage it has more to do with other circuits they are interfacing with e.g. arduino's or modular synths that have their own power requirements. I imagine people use regulators to reduce the irregularities that come about from a fluctuating power source, e.g. pitch shift induced by the sagging voltage of a 9v battery.

tjookum · Posted: Mon Jan 24, 2011 1:34 am Post subject:

Welcome!

I agree with Rich, it's a matter of personal preference, but when you only work with cmos 3-15V is fine. Although I have read that cmos IC's function just a tiny bit faster on 9v, but I've never noticed any difference.

I still get my power from the regulated 5v output of my arduino, basically because it was what I had laying around. I can really recommend building a good solid powersupply(preferably also with +/-12V) so you heavy a steady base to start from.
This is one of the most commonly used schematics but I have also seen them for DC wallwarts.
http://www.musicfromouterspace.com/analogsynth/WALLWARTSUPPLY/WALLWARTSUPPLY.php

I can really recommend starting out on breadboard and get yourself familiar with the cmos family. Good IC's to start with are the 4040,4051 and 4011.

most importantly, just have fun with it.

Psyingo · Joined: Jun 11, 2009 Posts: 248 Location: Canada

Hi Ringmad. Welcome.

To address the issue of power starve; you can have the best of both worlds. You can have a stable regulated power supply as a base, then for each individual module, you can have a power starve knob. or if thats too many knobs for you, you can have a universal starve knob. all the while having that regulated supply as the base.

a regulator isn't needed if you are going to run your device ONLY from batteries. but if you want to use an adapter it is best you use a regulator to stabilize the power and rid you of some hum.

5v is suggested because it's a pretty standard digital source and the regulators could probably be found easiest.

RingMad · Posted: Tue Jan 25, 2011 3:51 am Post subject:

Ok, thanks for the explanations and advice, people. Although for now I think I will stick with the 9V wallwart adapters I've been using for my other boxes. I'm a little impatient and would prefer to continue exploring new stuff rather than make a power supply... I've already breadboarded the melody generator (4017, 4051, 40106) and can't wait to explore more chips. I did make a quick little video, but didn't feel it was substantial enough yet to post in the "Let's see your Lunetta" thread.

RF · Posted: Tue Jan 25, 2011 5:13 am Post subject:

Draal · Posted: Wed Jan 26, 2011 1:34 pm Post subject:

Welcome to the club! I run mine off of a regulated 12v kit I bought a while back. Tons of useful info here to get you rolling.

Next time you are buying parts, get some 4018's or 4029's. Then search here for pitch makers. After you've got some oscillators and Gates, you can make some sweet melodies with these counters. Best of all, you're essentially bringing the pins out to the panel; I've got a few samples of the 4018 in action in that pitch maker topic and I consider it one the best ics that represent the lunetta vibe.

Enough of my rambling! I've got to get back to breadboarding yet another filter design Very Happy

.

RingMad · Posted: Wed Jan 26, 2011 4:18 pm Post subject:

Thanks Draal... I do have some 4029s, so I will be investigating those at some point... too many fun-looking circuits to try, not enough time! And BTW, I posted a photo and video of my first explorations in the "absolute beginners" thread...