I have a question regarding this - which of the terminals are electrically common?

(Pardon the crude drawing.)

@NathanOsman I think the answer is neither. But I don't use that kind of thing often. If you want to make your second version, you can use something like this:

amazon.ca/gp/product/B0143YQ9OE/…

There's another shape available if you want to make your first drawing.

I think your link is pretty similar to what I need.

How would I attach the wires though?

(What I mean to say, is how would they fasten to the prongs?)

@NathanOsman You put a spade lug on the wire too. Then screw the terminal down on the two spades together.

Maybe I wasn't clear. You use the "terminal jumper strip" and the terminal block together.

Oh, okay. Thanks.

Now it makes sense.

Yup, that's pretty much exactly what I need then. Thanks!

@jippie Oh, wow, thanks for reminding! :)

Sent

@Asmyldof in the video he says they must have naturally escaped

Mine could not escape lol

If someone again says that everyone should learn a bit programming, then I am going topunch them right int he face...

@PlasmaHH Want to borrow my brass knuckles?

@JRE nah, thanks, I ever liked the natural way and how it feels ^^

Hm, has anyone ever wondered how antenna grounding works in space probes?

Probably much like it works on cars.

minus the capacitance to earth

On the car, the "ground" is just the metal of the car itself. Provided the ground plane is larger than (I think) 1/4 the wavelength all is good - without a real earth ground.

Had a situation many years ago where we had a portable mobile two-way radio in UHF with an antenna with a magnetic base intended for use on cars/trucks. We needed to use it without the car or truck (two stories up, out of the window on a masonry building.) No earth ground, and no ground plane. The dealer gave us a square piece of sheet steel somewhat longer than the antenna. Antenna on the sheet, balanced on the window ledge, prblem solved.

hwhw

@PlasmaHH All antenna's are dipoles ... so is a car antenna and a space-craft antenna. Sometimes their just a bit harder to recognize.

I wonder if the db volume numbers on a receiver have any meaning

@PlasmaHH :'( That never happens to me

@PlasmaHH It's the amount of attenuation away from absolute physical destruction in my experience... #AlwaysListeningToMyMusicAt-50dB

@jippie They're

@ThePhoton (1) That looks like a regular smoke, not the magic smoke? (2) Why does it conveniently stand on a bed of gravel which is nonflammable?

@Asmyldof hm, in that sense it's the distance from party loudness ;) but it's probably not near intended as I have 4ohm speakers on 8ohm receiver

@NickAlexeev You know, if you're gonna light up magnesium, you should take precautions.

@ThePhoton Um... Was the chassis of that computer made of magnesium alloy?

Hello everyone!

> ... And besides that's how Snoop Dog always specifies electrolytic caps when he draws them on his schematics. ... FiddyOhm 2 hours ago

@ADG Hi.

@JRE Can you help me how can I make this

Ambitious if you've never done anything like it.

Microprocessor, serial shift registers for input (initial state) and output (LEDs,) LED drivers. You have a lot to learn and do before you are finished.

@JRE I can do it with microprocessors but I was thinking of logic gates

Then you've got a lot of work ahead of you. For each LED, you will need a circuit that counts how many other LEDs around it are lit. You will need to use the output of that to decide whether to turn the LED on or off. You will need 25 of those things to cover all LEDs. Seems to me like you would end up with a fairly large and complicated circuit board.

I'd start with one LED, and a hand full of switches to set the number of surrounding "live" cells. Get the logic for that straight, then build 25 of them.

@JRE he used some kind of shifter logic to select the current cell

that way he didnt had to make 25 of them...

one I could find was math.stackexchange.com/questions/297433/…

I was trying to find ways to sum 8 one-bit numbers and then its only 3-4 gates

That's the problem with YouTube videos. No details.

@JRe I believe he's a school student and has made a video just to show his project.. infact he mentioned some details

I also thought the same project incidentally and was searching the net for help

Yeah, but obviously not enough details to be able to reproduce it.

@JRE so what do you think... What logic can be used to choose 9 pins and shift them

Shift registers. 25 in to serial, to a second shift register that has 9 outputs. Connect those to your logic, and shift the result back to a register with 25 outputs to drive the LEDs.

@ADG Counting the number of set bits in 8 inputs doesn't reduce to any simple combination of AND and OR gates. But there's a number of ways to generate arbitrary truth tables, using either MUXes or ROMs. Or if you want to serialize the problem, consider shifting the bits representing the state of the neighbor cells across the CE pin of a counter.

Probably the cheapest way to do it with SSI/MSI chips.

I'm not sure if there's a clever way to figure out which cells are neighbors to simplify figuring out which signals to connect. Might be back to ROM or MUX logic.

@ThePhoton suppose if input are i0,i1,..i7 (surrounding bits) then I was thinking of taking full adder for i0,i1,i2 (one is Cin) and similarly for i3,i4,i5 and then half adder for i6,i7 [All these using 7486,7408,7432] then addign first two sums with 7483 and then again with 7483

Or maybe there's a clever way to number the cells in the array to make it easy to figure out which ones are neighbors.

@ADG Also would work

if it was to be microcontrolled then there was no problem

currently im trying in logism to make it work for 9 inputs without and clock

@ADG what's an "and clock"?

@ThePhoton Not so much number as arrange the order they are connected to the shift register. Don't know if there is an optimal or correct arrangement.

@ThePhoton sorry, my english, i mean any clock input/d-flipflops

@ADG I wouldn't make that restriction. The clock is your friend.

If you are going to use serial shift registers, then you will need a clock.

Ateast first let me make a logic like [this](math.stackexchange.com/questions/297433/… not)exactly but using 7400 series

Yes you are right.

reached this stage