Search found 18 matches

by jalbers
Mon Jun 23, 2008 10:56 am
Forum: General Discussion
Topic: Theory behing 110 V AC RC driver Circuit ???
Replies: 9
Views: 2812

Sorry about the multiple postings. After I hit submit, I waited about 10 miniutes for something to happen. I figured something was wrong so I hit the back button and tried again.
by jalbers
Mon Jun 23, 2008 10:03 am
Forum: General Discussion
Topic: Theory behing 110 V AC RC driver Circuit ???
Replies: 9
Views: 2812

Theory behing 110 V AC RC driver Circuit ???

A while back I saw a post about powering an LED using 110V AC. The circuit consisted of wiring the LED in series with a 1K resister and .1 uF capacitor. A reversed diode was also wired in parallel with the LED to protect the LED from reverse bias. I have a few questions about the circuit: 1. How wer...
by jalbers
Mon Jun 23, 2008 4:52 am
Forum: General Discussion
Topic: Help with LRC, Complex Numbers ???
Replies: 1
Views: 856

Help with LRC, Complex Numbers ???

I am trying to understand XLR circuits and the use of complex numbers to find solutions. I think that I am applying and interpreting the math correctly but would feel more comfortable if someone with more experience took a look at what I am doing... Suppose that a 50 ohm resistor, 1 uH inductor, and...
by jalbers
Mon Sep 19, 2005 7:56 am
Forum: General Discussion
Topic: Naked PC power supply
Replies: 8
Views: 1842

Naked PC power supply

I am trying to get some PC power supplies to work with not computer attached. I know they won't start without a load so I have tried connecting up a floppy drive, hard drive, and CD drive at the same time but the power supply still won't come on. It is one of the newer types of supples with no on/of...
by jalbers
Wed Sep 14, 2005 8:51 am
Forum: General Discussion
Topic: How to directly hook up Nidec HD Spindle Motor???
Replies: 3
Views: 1198

Re: How to directly hook up Nidec HD Spindle Motor???

Thank you for your replies. I am leaning towards just using the circuit board supplied with the HD to run the motor. However, when I try this the drive will spin up to full speed and run for about a minute then it will shut off. If I disconnect power and reconnect the drive will run for another minu...
by jalbers
Tue Sep 13, 2005 12:00 pm
Forum: General Discussion
Topic: How to directly hook up Nidec HD Spindle Motor???
Replies: 3
Views: 1198

How to directly hook up Nidec HD Spindle Motor???

I have a bunch of old computer hard drives that I am taking apart to salvage the magnets, bearings, platters, and other misc parts. They have Nidec 59-004046-001 spindle motors that I want to try to hook up directly to power if possible to make them run. I am looking for a data sheet on this motor. ...
by jalbers
Wed Apr 28, 2004 6:32 am
Forum: General Discussion
Topic: Can't identify type of gate in diagram explaining inner
Replies: 1
Views: 729

Can't identify type of gate in diagram explaining inner

There is a really good graphical simulation of the inner worrkings of a 555 timer chip at http://www.williamson-labs.com/ under 555 on the left frame.<p>However, I am trying to follow what is happening and think that I almost understand. I need some clarification of what type of logic gate is just b...
by jalbers
Tue Dec 30, 2003 12:47 pm
Forum: General Discussion
Topic: Where's the spark ??
Replies: 6
Views: 1334

Where's the spark ??

I am thinking about building an EDM (electric discharge machine) which remove tiny bits of metal by sparks. I have found plans and schematics on the web and in various magazines like Home Machinsts Workshop. I could just blindly copy their designs, but I wanted to understand how they work first. Mos...
by jalbers
Wed Feb 19, 2003 9:53 am
Forum: General Discussion
Topic: Motion Detection in NTSC Signal
Replies: 5
Views: 1418

Re: Motion Detection in NTSC Signal

This sounds interesting. How do you find the average voltage level? I have a feeling it is some type of circuit using op amps.
by jalbers
Thu Feb 13, 2003 1:17 pm
Forum: General Discussion
Topic: Poptronics Is Gone???
Replies: 48
Views: 14999

Re: Poptronics Is Gone???

Check out http://www.epemag.wimborne.co.uk/<p>You can subsribe to this magazine and download it in .pdf format each month. It is just as good as Poptronics.
by jalbers
Thu Feb 13, 2003 1:09 pm
Forum: General Discussion
Topic: Motion Detection in NTSC Signal
Replies: 5
Views: 1418

Motion Detection in NTSC Signal

I am looking for information on how to detect motion in NTSC signal from one of those cheap 1" square cameras. Is there a cheap off the shelf chip or little black box that could look for changes in the NTSC signal? I am currently only interested in black and white. I am sure that this is not the fir...
by jalbers
Wed Mar 27, 2002 6:47 am
Forum: General Discussion
Topic: Need help with Quardatrue Encoder Theory
Replies: 4
Views: 3203

Need help with Quardatrue Encoder Theory

To test my understanding of how a quadrature rotational encoder works, I set out to design a software simulator. To keep things simple, I decided to simulate a wheel with 8 evenly spaced holes. I should be able to get 4 times the resolution or a total resolution of 32. However I cannot figure out wh...
by jalbers
Tue Jan 08, 2002 1:13 pm
Forum: General Discussion
Topic: Puzzled about current producing devices ??
Replies: 2
Views: 1485

Puzzled about current producing devices ??

I have been studying various op-amp circuits and I have come across the current to voltage convertor circuit. I am slightly puzzled by the term "current producing device" in the circuit. Wouldn't there also be some sort of voltage produced across this device's terminals?
by jalbers
Thu Dec 20, 2001 5:03 am
Forum: General Discussion
Topic: Help with simple diode circuit ???
Replies: 13
Views: 5370

Re: Help with simple diode circuit ???

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by john albers:
[QB][/QB]I mean reply with quote button. I think that you also have to type your message between the quote tags.<hr></blockquote>
by jalbers
Thu Dec 20, 2001 5:01 am
Forum: General Discussion
Topic: Help with simple diode circuit ???
Replies: 13
Views: 5370

Re: Help with simple diode circuit ???

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by RonH:
John Albers knows how to post a quote. You there, John?<p>I clicked on the post with quote button.<p>Ron H<hr></blockquote>