|
I remember back in the early 80's while attending tech, playing with nixie tubes we found at a surplus store to make a clock.
Here's a new take on old tech. Smart Nixie Tube[^] Very cool.
[Edit] Fix broken link, Thanks Dave. 
It was broke, so I fixed it.
modified 4-Feb-14 14:09pm.
|
|
|
|
|
|
Fixed.
It was broke, so I fixed it.
|
|
|
|
|
|
Oh, I've got to get me some of those! Very 
|
|
|
|
|
When you build something so retro, then you also need the oldest processor you can get. Here[^] is a clock that has been built with regular tubes and a CDP1802 processor. The minimal circuit (CPU, memory and clock plus drivers for the tubes) should be easy to build and to program and is 100% CMOS, which should help to work with the voltages needed to drive the tubes.
The language is JavaScript. that of Mordor, which I will not utter here
I hold an A-7 computer expert classification, Commodore. I'm well acquainted with Dr. Daystrom's theories and discoveries. The basic design of all our ship's computers are JavaScript.
|
|
|
|
|
Hi All,
Very nearly asked a dumb question in the VB Q&A, as I was typing it I saw what I was doing wrong.
Third time I have done that this week so far whats the betting I will get to double digits by Friday.
|
|
|
|
|
Sometimes framing the question and providing the pertnent information reveals the issue. You're becoming quite the VB guru. 
It was broke, so I fixed it.
|
|
|
|
|
Now take that back right now! 
|
|
|
|
|
Better a face palm than a face plant.
And yeah, I've done that too. My shtick is to explain to why something cannot be done, which often triggers the revelation of how it can be done. Which has resulted in the uncomfortable reputation of "Let him be grumpy: he's far more productive after he's had a chance to say no."
|
|
|
|
|
Gregory.Gadow wrote: uncomfortable reputation of "Let him be grumpy: he's far more productive after he's had a chance to say no."
That's me all over tell me something can't be done and its my nature to find out...
|
|
|
|
|
That's why you're on VB duty now.
|
|
|
|
|
Mutter, mutter, mutter!
|
|
|
|
|
By week end you'll have a red forehead and a big headache?
I got both just from today!
Bad wire on protoboard, was working then changed platforms and stopped working, and then when I replaced it the circuit started working but ohmed out the cable and it tested good??? I hate it when that happens!
|
|
|
|
|
It often helps to ask the duck[^].
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
|
|
|
|
|
Mmm...heard a similar story involving a Teddy Bear Often you know the answer or a way to work it out it just helps to say it a different way!
|
|
|
|
|
I've a question about the subwoofer that came with my home theater system (Samsung HT-F5500W). Based on where the feet on it are, it is designed to be laid such that the speaker faces to the side. I know I can physically do it, but what would be the drawbacks on laying it such that the speaker faces up? Damage the electronics? Not hear the thump, thump, thumps as well?
Thank you.
- DC
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
|
|
|
|
|
Does the subwoofer has feet (rubber or other types) ? if so, placing it in a different position might cause additional vibrations since it will not be cushioned.
I'd buy some sticky rubber feet and stick them on the side that will be on the floor.
As for the sound, it will be less loud and less clearer.
I'd rather be phishing!
|
|
|
|
|
Grasping at straws, but the cone/coils will be pushing against gravity. In theory this'll change the waveform generated? Don't know if the difference will be perceptible.
|
|
|
|
|
Speakers are constructed in a manner such that they don't care which direction the cone points. Most people really don't "hear" a subwoofer anyway, but rather feel the vast (as compared to mid-range & tweeter speakers) amount of air that the sub woofer moves.
Speakers respond to their enclosures, vents etc. according to something called the Thiele/Small equations. See Wikipedia under Thiele/Small.
When I built my stereo system years ago, I had access to the engineers at Electro Voice. I got a 18" subwoofer and built a stand-alone cabinet according to the equations. It wound up at approximately 2' x 2' x 4'. It has its own dedicated 500 watt amplifier and if I play Michael Jackson's "Billy Jean" and stand next to the speaker, my pants legs move on the downbeat.
Bottom line is that you aren't going to hear or feel the difference. If the base seems a little lacking, turn it up until it sounds like you want it to sound.
Barry
|
|
|
|
|
BarryPearlman wrote: Speakers are constructed in a manner such that they don't care which direction the cone points
Correct, in the older cars the speakers were in the back ?shelf? (forgot what it's called) and pointing up.
|
|
|
|
|
I seem to recall it was a parcel shelf, though anyone daft enough to put parcels on it was asking for trouble. This was a time when seat backs stopped at shoulder level (and no seat belts in the back (UK)). The number of injuries from rear seat passengers and parcels striking the driver was quite high as I remember.
|
|
|
|
|
I guess largely correct. The sound of sub-woofers designed to have the cone pointed downwards towards the floor can be affected as the space between the floor and cone acts like a short transmission line or have some other kind of acoustic effect.
Please correct if I am totally wrong in my assumption.
|
|
|
|
|
BarryPearlman wrote: if I play Michael Jackson's "Billy Jean" and stand next to the speaker, my pants legs move on the downbeat.
That is a mental picture I really didn't need. 
|
|
|
|
|
You aren't grasping straws[^].
A "up" mounted subwoofer will not only have the rest position moved downward, also, the suspension - basically rubber and resined paper - will "learn" the new position, so that bringing it into "front" position will take while to forget this.
In principle, this shift can be a major source of additional distortion.
Wether this matters dependes on the particular sub woofer. Car aftermarked subwoofers are often built with a long "overhang coil" (the coil is longer than the magnetic gap), which means rest psoition doesn't matter much - but it takes more power and onset of distortion is more abrupt.
In a short coil configuration, a change in rest position is indeed a major thing (and it's indeed a major thing for us to be able to detect such a shift in a 200ms end of line test).
Even then, many "home entertainment" subwoofers are built to basically repoduce a single frequency to get good "whoomp". If you have a "whoomp" woofer with a decent crossover - i.e. the woofer doesn't "see" the higher frequencies - there's little that could be noticed. Good enough for hip hop, sucks for Bach.
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
