Modding Knightrider/HDD meter

It may also be a good thing to note that the resistor between pins 6,7 and 8,4 of the LM3914 is used to set current draw through the led's.
3.3K ohm resistor may deliver too little current for some LED's.
Lower the resistance and you will increase current capacity.
Be careful how low your resistance is because this chip LM3914 can deliver up up to 30ma, which may be too much for your LED's.

The Data sheet on National Semi's web site explains how to set this value.

http://www.national.com/

Goodday all

 

ok. I am not sure what I did wrong with mine, but here you go:

Wantimg to buy
1 etched board for a single led bard. Not interested in it doing anything except the knightrider effect. No HDD monitoring or anything else. I have all the parts but my board is wrong somehow and Im not sure. I prefer a board from a well known person on the board and most important in the US to reduce shipping costs.

 

I'm actually in the process of making a mouse pad using a modified version of this circuit.
Between work, wife and kids, it's taking forever though :sigh

 

Sounds interesting - look forward to seeing the pics

 

hi every1.. i'm from australia and i cant find VR1 and VR3... i found VR2 in jaycar... i lookin in jaycar and dick smith and none of them have 220k and 4k7 multiturn trimpots. have anyone done Knightrider in au? if yes then where did u get VR1 and VR3 from ? if i cant find them, is there any other methods or something else i can use instead?

btw... macro, ur an electronics G0D i wish i had quater the skills u have and half the imagination keep up good work and keep makin some new things..

 

actually i didnt even find a proper VR2 these 3 components holding me back on makin knightrider.. if any1 has any info of where to get them in australia or has some spare ones i'll pay for parts and postage, plz help

 

The potentiometers do not have to be exact values, they are meant for adjustment not to be exact.

I used a 200k for the 220k, and a 5k for the 4.7k. VR1 is an adjustment for frequency. The higher the value, the less current there is to charge the 47uf capacitor, the slower the display will run.

The other two potentiometers are meant to adjust the sweep so that you get all the led's to light.

 

cool thanx.. one thing tho.. vr's sold in jaycar dont quiet look like the ones used in that circuit.. all pins r inline.. so that means i'll have to modify the circuit

 

will anyone make me a board?

 

i'd luv one too plz.. i'll pay for your time, material and postage

 

Part of the beauty of this circuit is in the analog design, and the do it yourself quality of it.
If doing it yourself isn't rally your cup of tea (Earl Grey here) then there are places on the net that have these kind of displays pre-built and for sale for around the same price it would take to build one yourself, or have someone on here build.
If you don't have any takers you might try one of these places.

Here's one.

http://www.knightlight.co.uk/index.htm

I like to do things myself, but this is a way to go.

 

First off when talking about electronics, I know less about it then I do about women... meaning I know next to nothing... but I'm learning (learning included giving a six-pack to my bros who's an electrical engeneer so he'll show me the basics).

For my first project I want to build either the Knightrider circuit or the Hard-drive meter.

I was wondering can you substitute the LED's with some Neon-string or EL-cable? If so how would I do this?

 

It would be Possible to do that, but it would also be complicated.
It would probably be a better idea to come up with a diferent circuit unless your planning on putting 10 inverters in your case.
Anyway in theory how you would go about it would be to use the output of the LM3914 as an input to a driver like a fet or transistor to turn the inverter on and off. This of course sounds easier than it actually is.
Probably not a good idea since you don't know anything about electronics.
You could probably do somthing smaller scale...... make a four bit counter out of discrete logic chips, or do a programable IC..... or you could write software for your parallel port, and use the outputs from that to switch invertrs on and off.... I could go on, but I have to work.

 

Yup, I think your right sounds a little more complicated then I thought.... hmmm guess I have to find a different method, but isn't that what moddin is about...

PS: I'm at work too... since I'm a techie, they think I'm reserching... and in a way I am.

 

How many pieces of EL Cable are you talking about?

 

You could use this circuit to switch the gates of several FET's with the output of one inverter at the source of each FET and the EL's on the Drain with a common return to the inverter.

Still complicated , but it's about the cleanest way I can think to do this.

And, you're right.... That's what modding is about....... Unless you're bad at it. Then it's about breakin stuff..... and possibly causing fires.

 

Here is an option that would not require an inverter at all. This circut would require no modifying from what they have already given us here. The results might be desireable, and cheep enough...

Ok, here's my idea. Insead of using expensive EL wire, and noisy inverters, use LED's and Fiber Optic line. Sand the sides of the fiber, and all the suden, the whole thing glows if you put an LED at one end. Put one at each end for added brightness. Then you could have 10 of them and no hastle.

Just a thought, but I think it's a good one. It's a modders solution!

 

Awsome Idea

 

other sequenses

Hello, Im about to make the HDD meter as a project at school, and Im wondering about if it is possible to make the led's to go in a circle?, not back and forth. I realy want appreciate if anyone could make me a drawing of a circuit then

tanhx.

 

Like This

Put a diode in parallel with VR1.
lower R5's resistance to around 500 ohms.
This will work with the gated version of the circuit.
Located here
http://www.bit-tech.net/images/article/82/hdd_gate.gif
I think that you would be better off using a 4017 to get the effect you want though. You can attach the clock input to the HDD output from your motherboard , and the led's will light in sequence every time your Hard drive is accessed.