How to plug a LED ?

[Puck]

I think I know the type of board you speaketh of. You should still be able to construct this circuit on one of those, soldering would be better though really. It's fairly easy to do!

 

For fading... I think you might be able to put a capacitor from the transistors base, after the resistor, to ground. Not completely sure on that though. It might not be a particularly accurate fade either.

 

The schematic I posted was drawn with CadSoft Eagle. It's a schematic / PCB design software. It's got a bit of a learning curve to it and there are other things for drawing PCB layouts and schematics you may find easier to use.

 

The simulator I used is called LTSpice or SWCADIII. It's quite complicated. I don't even know how to use many features I do remember back in high school we had something called Crocodile Clips, which was awesome and would probably be more helpful to you! I'm not sure if that's freeware though.

 

 

 

 

Sorry, IC2 is an "NE555N" or "LM555N" and IC1 is "CD4017".

 

NE555N - http://search.digikey.com/scripts/DkSearch...amp;x=0&y=0

CD4017 - http://search.digikey.com/scripts/DkSearch...ds=cd4017%20dip

LM555N is EVERYWHERE, and should be very easy to find. Not sure about the 4017 timer chip.

 

Have your tried MultiSIM 8 or 9? It is both a circuit design suite and simulator in one. It has its quirks(I use ver.8 since I got a copy through one of my circuit design classes and have never tried 9), but is very easy to use and easier to get into its advanced features. The library it comes with comes with just about every component from common basic IC's to complex pre made circuits to import into your own work, and each component can be customized for the specific values needed(temperature tolerance, failure rate(components can randomly fail just like in real life), voltage tolerance, etc).

 

The simulation is also straight forward, and the timing and such can be adjusted from very slow to watch which parts break down first under extreme conditions(like improperly connected LEDs ) to realtime simulating, just like with some of the bigger programs. At first I hated it for its small quirks(like having to stop/start the simulation after changing parts or the results sometimes dont change), but have come to find it pretty handy overall.

[The Smith]

Maybe I will try to get one of those programs someday...

[The Smith]

Hi,

 

I bought all the pieces I need to make this circuit, except IC1, I ordered it. I have two questions about plugging.

 

1st: The screw terminal connector. When you say that it is a power supply input, how do I plug it in ?

 

2nd:Which pin is the base current on the Q1 transistors ? And which is the positive ?

 

Thank you,

 

The Smith

[markiemrboo]

Have your tried MultiSIM 8 or 9? It is both a circuit design suite and simulator in one.

 

It doesn't appear to be free

 

 

1st: The screw terminal connector. When you say that it is a power supply input, how do I plug it in ?

 

I'm not sure of the question. 12V goes to 12V, GND goes to ground. You will probably have to make up a 4 pin molex plug with two wires, one 12v (the yellow wire) and one ground (the black wire next to the yellow wire). Put 12v wire to 12v point on your board, put ground wire to GND point on your board.

 

2nd:Which pin is the base current on the Q1 transistors ? And which is the positive ?

 

 

As for the transistor pin out, if you hold it so that the flat side is facing toward you and pins going down toward the floor, then the pin on the left will be the emitter, the middle pin the base, and the pin on the right the collector. The emitter in the schematic symbol is represented by the small arrow pointing towards ground, and the collector is the pin with the LED connected to it. You should be able to work out which is the base

 

Pin outs can sometimes vary between different manufacturers, so it may be wise to search for data sheets just to make sure!

 

 

The emitter goes to ground. The collector to the LED.

[The Smith]

Oops...I didn't re-read your post before asking the question on the transistor...Sorry for that.

 

Edit:This is what I have done so far for the power, as you said, but I don't know what to do with the X_Power:

Edited March 7, 2008 by The Smith

[markiemrboo]

You just need one more ground connection to the GND point near X_POWER and it looks like you're all set!

[The Smith]

Euh...yes, I just forgot to draw it, I was in a hurry to go eat.

 

But what do I do with the screw terminal connector ? I bought a small piece to be soldered on my board which leads to two screws. I thought I would need to put this as the X_Power 1 and 2, but are you saying that X_Power is not a physical piece ? Nothing is to be placed there ?

Edited March 8, 2008 by The Smith

[markiemrboo]

It can be a physical piece. I didn't realise you had bought the connector.

 

Molex wires goes to screw terminal, join all power connections on the board.

 

edit: sorry, that image was slightly wrong!

 

edit: this one should be right-er

 

Edited March 8, 2008 by markiemrboo

[The Smith]

Ok, now I understand !

 

I directly plug all the +12 V and Gnd to the molex connector OR I plug the X_Power, joining the +12V together and the same with Gnd.

 

I will be refunded for the 1 $ piece I bought.

 

Thank you very much for your patience, Markiemrboo.

 

The Smith

[markiemrboo]

Ok, now I understand !

 

I directly plug all the +12 V and Gnd to the molex connector OR I plug the X_Power, joining the +12V together and the same with Gnd.

 

I will be refunded for the 1 $ piece I bought.

 

Thank you very much for your patience, Markiemrboo.

 

The Smith

 

You can of course solder the 12v and GND wires from the molex to some point on the board, then join all of the boards 12v and GND to those points... just like the screw terminal way, but without the screw terminal. It would be neater and easier than having lots of separate wires coming out of the molex. Or perhaps that is what you meant.

 

No problem anyway. I hope we will get to see pictures and / or a small video (webcam?) of it working!

[The Smith]

Hi again,

 

I received all the pieces I needed for the circuit. Just want to be sure of the pins of the ICs. This week, we got a demo at school of a electrolytic capacitor exploding, and I don't want my ICs to do the same !

 

So, I am a bit confused about the small dot to identify the 1st pin. Which of them is it ? I think it is the round one, not on the side, but I wanted to be sure.

 

And for the variable resistor, too. It has 3 pins, one in the middle which is not aligned with the other two. Which pin is what ?

 

Thanks in advance!

Edited March 15, 2008 by The Smith

[markiemrboo]

Hi again,

 

I received all the pieces I needed for the circuit. Just want to be sure of the pins of the ICs. This week, we got a demo at school of a electrolytic capacitor exploding, and I don't want my ICs to do the same !

 

So, I am a bit confused about the small dot to identify the 1st pin. Which of them is it ? I think it is the round one, not on the side, but I wanted to be sure.

 

Thanks in advance!

 

Oh, in this case it'll be the U looking one.

 

  _____
1|  U  |16
2|	 |15
3|	 |14
4|	 |13
5|	 |12
6|	 |11
7|	 |10
8|  o  |9

 

 

 

edit - The middle pin tends to be the wiper. This might help you understand a bit better. http://www.kpsec.freeuk.com/components/vres.htm

Edited March 15, 2008 by markiemrboo