Electronic Circuit Question

[jbaldwinroberts]

I was looking at this mod guide
http://www.modders-inc.com/how-to-story--19.html
on the internet and decided i wanted to do something a bit different, but as i have no idea about electronics i need a bit of help.

What i want to do is incorperate a circle of blue leds around my power on button so that when the key is turned they scroll round clockwise quite slowly, this is the first thing i dont know how to do. the next thing i wanted to do was to make the leds stop scrolling when the power button is pressed and the computer is turned on, this circle of blue leds would then become the hard drive activity indicator.

if can give me any help with this, or have any questions as i probably havnt explained it very well please ask.

thankyou for any help.

Joe

[DaveW]

I'll move this to the electronics forum, where It might get more attention.

This sounds tricky, but it can be done in a variety of ways.

1) Something like a 555 timer and a collection of transistors.

2) By programming something like a PIC microprocessor.

I'm a programmer, so I'd make a PIC, but most electronics guys would prefer to opt for the first. They would probably both cost roughly the same, if I assume you only need to buy the components. If you have no tools at all, then the first one will be cheapest. I think I see what you're aiming for, but that's all the help I have time to give at the moment, sorry!

-Dave

[jbaldwinroberts]

yes i think i have all the tools i will need.

Sorry it was in the wrong forum, thanks for moving it.

any other ideas/help??

thanks

[slytherock]

Those are 2 differents circuits, but can be join together. THe problem is that I dont remember how (my electronic degree is way behind me) I can try to look into my books, but it can take time cause I'm mving this WeekEnd.

You can easily find some electronic shema on the net.
here's an exemple: http://www.tehnomagazin.com/Schemati...c_projects.htm

[jbaldwinroberts]

what two cicuits would these be and where can i find out some more information about them??

a way of joining them would be great as would any extra help, as i am i no rush.

thanks

[slytherock]

2 circuits: one for the rotating leds, and one for the HDD activity.
For the HDD activity, it's really simple, just a connection to the mobo. May need a relay to power up more leds.
For the key switch; search for alternating leds, or something like that.

I'll search on my side for how to separate 2 circuits on the same schema.

[jbaldwinroberts]

Thankyou. Any help is much appreciated.

[jbaldwinroberts]

I have changed my idea slightly, i was wondering if it would be possible to have the whole ring of leds slowly pulsate on and off when the key is turned and then for the roatating leds to simulate the hard drive activity, i.e rotate faster the more activity and slower for less activity

i found a good little hard drive chaser circuit here
http://metku.net/index.html?sect=vie...lot2/index_eng
but i would need to change it to workonly when the computer is on not when the key is turned.

i also found a cricuit to make the leds pulse that i would connect to the key switch so thay would run when the key is turned. i would also need to change this so it stopped when the computer is powered on. would this circuit work??
http://metku.net/index.html?path=mod...fade/index_eng

Also how would i make them so that they can both use the same leds.

thanks

[xmastree]

Hmm... A couple of ideas spring to mind.

Firstly, a 4017 and a 555 will give you a 'running light' effect.


But... I have a better idea.

Using a 3914 is a bargraph driver chip (similar to a vu meter) which with a bit of additional circuitry can be made to give a nice effect.

If you use your hd activity light to control a RC network (basically charging a capacitor when the light is on, letting it discharge when off) the 'meter' will start at zero and rise to 100% as the disk is accessed. The flashing of the normal light will become a 'bouncing' of the meter (think - vu meter again).

That could look quite neat, if that's the effect you want.

Making it do the power thing too would be awkward though.

[slytherock]

After a bit of thiniking, I came to a conclusion:
Since there's no power in a rig till the mobo gets on, you'll need an external power source for the key leds...