Search found 13 matches

by Marcaroni
Thu Sep 22, 2011 12:25 pm
Forum: General Discussion
Topic: "see-saw" pot output (beginner's question)
Replies: 6
Views: 1518

Re: "see-saw" pot output (beginner's question)

Sorry, if I'm a bit late answering this. But what a bout using something like an L-Pad instead of a standard carbon potentiometer? I've used L-Pads in 150 watt RMS speakers, and each L-Pad was rated at 200 watts. Here is how they are used with speakers. http://www.colomar.com/Shavano/lpad.html But ...
by Marcaroni
Thu Sep 22, 2011 8:59 am
Forum: General Discussion
Topic: "see-saw" pot output (beginner's question)
Replies: 6
Views: 1518

Re: "see-saw" pot output (beginner's question)

I haven't actually attempted this yet. I'm not exactly sure where to start. I'd like to have a circuit with a single potentiometer that drives 2 outputs operating like a "see-saw". so as i adjust the pot "up," one output increases in voltage as the other decreases and vice versa. so whenever the ou...
by Marcaroni
Thu Sep 22, 2011 8:09 am
Forum: General Discussion
Topic: "see-saw" pot output (beginner's question)
Replies: 6
Views: 1518

"see-saw" pot output (beginner's question)

I haven't actually attempted this yet. I'm not exactly sure where to start. I'd like to have a circuit with a single potentiometer that drives 2 outputs operating like a "see-saw". so as i adjust the pot "up," one output increases in voltage as the other decreases and vice versa. so whenever the out...
by Marcaroni
Fri Apr 30, 2010 2:38 pm
Forum: General Discussion
Topic: Square wave noise filter
Replies: 4
Views: 1081

Re: Square wave noise filter

Just another follow up. I made the diode mod, reassembled the entire system and tested all the valves with actual fluid. The difference is much more dramatic than I expected. The valves are much more obedient now. I'm seeing a huge increase in stability. Unfortunately for me, my software needs to be...
by Marcaroni
Fri Apr 30, 2010 11:04 am
Forum: General Discussion
Topic: Square wave noise filter
Replies: 4
Views: 1081

Re: Square wave noise filter

Hi MrAl, I appreciate the super fast response. I had some 1N4003's laying around to test it. Initial testing shows the spike is definitely gone. All I did was clip the 1N4003's across the valve leads. Below 15% PWM there's a small "kink" in the wave form on the low cycle. I'm sorry I can't explain i...
by Marcaroni
Fri Apr 30, 2010 8:06 am
Forum: General Discussion
Topic: Square wave noise filter
Replies: 4
Views: 1081

Square wave noise filter

Hello everyone, I'm in a bit over my head on my first "non-kit" project. I'm using an Atmel UC3B ( http://www.atmel.com/dyn/resources/prod_documents/32059S.pdf ) to produce 4 independent PWM signals. At this point it seems to be working perfect. I run those PWM output signals through IRL640 N-Channe...
by Marcaroni
Thu Mar 26, 2009 10:57 am
Forum: General Discussion
Topic: Mass wire storage solutions
Replies: 11
Views: 3369

Re: Mass wire storage solutions

At work we use a 2 drawer filing cabinet that sits under the bench. each cable has its own file. definitely not the cheapest solution but it works out really well. we also have a pomona rack for more frequently used, smaller cables.

-Marcaroni
by Marcaroni
Fri Jan 02, 2009 5:11 am
Forum: General Discussion
Topic: High res PWM
Replies: 4
Views: 1716

Re: What about uP

Can't you use a microprocessor like one of the inexpemsive Picaxe chips ? At 4MHz up to 20KHz PWM and at at 8 MHz double that. From 0% to 100% duty at fixed frequency, unlike the interdependency of the 555 timer where a duty change also changes the frequency. Just a thought. we probably will end up...
by Marcaroni
Fri Jan 02, 2009 4:55 am
Forum: General Discussion
Topic: High res PWM
Replies: 4
Views: 1716

Nepo wrote:I don’t have an answer to your question, but what is it that you’re using PWM to control?

these valves:
http://www.sensortechnics.com/index.php ... 1f733a8d26
by Marcaroni
Thu Dec 18, 2008 3:36 pm
Forum: General Discussion
Topic: High res PWM
Replies: 4
Views: 1716

High res PWM

Hi. I'm currently using an RS232 PWM control board from NCD (PWM85 www.controlanything.com). The board takes simple commands via RS232 to control 8 individual channels of PWM output. The problem I'm having is the resolution. It only has 8-bit control...which seems common, so i'm guessing that's fine...
by Marcaroni
Sun Jun 08, 2008 9:58 pm
Forum: General Discussion
Topic: RS232 --> ??? --> 0-5VDC/0-700mA
Replies: 5
Views: 2122

Where did you find the RS232 pot? It sounds like a simpler version of something I've been planning to build for a long time. http://www.controlanything.com their toys are tons of fun. their web site is not. it's some where down the left menu under "digital potentiometers" - usb and rs232 varieties....
by Marcaroni
Sat Jun 07, 2008 5:25 am
Forum: General Discussion
Topic: RS232 --> ??? --> 0-5VDC/0-700mA
Replies: 5
Views: 2122

Awesome. Thank you MrAl and dyarker.
by Marcaroni
Fri Jun 06, 2008 2:30 pm
Forum: General Discussion
Topic: RS232 --> ??? --> 0-5VDC/0-700mA
Replies: 5
Views: 2122

RS232 --> ??? --> 0-5VDC/0-700mA

Hello, This is my first post, please go easy on me. I'm also fairly new to electronics so please forgive me if my terminology is weak. I've started a little project but i think i may have gotten in a little over my head. I purchased an RS232 controlled potentiometer board. I've already written some ...