Modding Knightrider/HDD meter

I'm picking up the parts this week... and hopefully taking a movie snippet when it's finished. I wasn't sure about the resistor or capacitor values... the chip runs up to 15V so I figured it's okay. Does the 4017 always have the same output voltage or does that differ on the input voltage? I don't wanna blow away my super ultra bright LED's.

 

Yes you need to calculate resistor values for your LED's. Unlike the chip used for the knight rider circuit the 4017 doesn't have current limiting. It's meant to drive logic, not LED's, so your outputs will be close to VCC +- for a logic Hi (LED on) and Close to Return for a logic low (LED off).

All you need to know to calculate resistance values is your supply voltage, and the amount of current you want to flow through your LED witch should be some value less than what the LED is rated for. You should also check the data sheet for the chip you are using. Specs on this chip vary from package to package, and the chip may not be able to handle the kind of current you need t light your LED's to the brightness you want. You may need a driver chip, or discreet transistors to get the current you want.



Regardless, you should still have the resistors.

 

I would just like to point out that your circuit will leave a random led lit after hdd activity.

You can get around this problem by using a 555 timer to feed pulses into the CLK pin of IC1, take the RES pin to 12V via a resistor (say 10K - 100K) and use the opto to drive this pin low during hdd activity. This arrangement works, I used it several years ago as a hdd activity meter. If I get time I can put up a cct if needed.

 

An artist he is

 

Do any of my US brethren have an updated parts list? Both the article and all the posts I could find seem to be outdated.

 

Macro, I've redone your schematic in Eagle, and come up with the following:



two sided board (going for soldermasking) using SMD resistors, might also uses SMD capacitors (if I can find the right kind or stick to the regular kind)....

What do you think?

Also would this work for leds with a fv of 2.1v and if of 20mA? I'm pretty sure cause this is pretty standard. Also looking at the datasheet for the lm3914, 12/R1 is said to be Iled and as far as I can see, that would work out to: 3.6mA, and some where in the pdf it said '10 times this current will be drawn through each led' == 36mA....

Regards, Mike

PS: I used the 4N35 model in Eagle as there is no 4N25, I guess same packaging....

 

Eagle is driving me nuts. how on earth can I add pin 8/4 of the dual opamp to the schematic?

ARGH!

 

The power pins (4/8) are a seperate (but included) part. You need to select the op-amp and then click on "add gate" to add them to the circuit diagram. They will appear as two verticle lines which you then connect to the appropriate power rails.

 

Add brilliant, thanks! Just went to the shop and got the SMD resistors but in 1206 packaging, however i'm using 1210 solderpads as I've heard its easier to work with these eitherway.

I've checked that the optoisolator is also in 6pin dil packaging, so using the 4N35 device is not a problem. I will update my image soon.

Thanks a lot macro! I will be using 'holders' as well.

 

hi,

i think im being a bit of an AFM but i cant get this to work. I built the knightrider (no hdd activity cct) on breadboard & it was fine, but ive transfered it to stripboard & absolutely nothing happens.

Ive set the resistors as suggested in the article, & have checked a few voltages, but i cant work out whats wrong.

The main things i dont think are right are that the output from the LM4558N isnt ramping up and down at all, and although 1 side of the LEDs is at 12V, the cathode it about 9!?

any help would be really appreciated!

Thanks in advance,

RoB

 

Knightrider Circuit....

Macroman... Great job on the knight rider circuits. Just an off the wall question though... Would the LM3914 outputs be able to light an LED and switch a transistor also? Say like an 2N3055 with the emitter to +12V and the Base to a 1K ohm resistor, the other end to the LM3914 Outputs, and the collector to a lamp?? The origional Knight Rider circuit actually had 8-100W, 12V lights that it used. Battery Suckers!!

 

newbie

hello everyone you guys are all great
im using EAGLE to make the PCB and i was wondering if on the HDD activity meter board if the copper around the components is actually needed or whether it was just left there
cheers

EDIT: Never mind i got Paint Shop Pro

 

Re: Knightrider Circuit....

Welcome, Tubeampguru.

The LM3914 outputs go low when "on" so a PNP transistor would work best.

To switch 8A or so, a single power transistor with gain around 20 would need a base current over 400mA so that's out.

High-gain PNP followed by power NPN, a PNP Power Darlington or a P MOSFET would be OK.

 

Re: newbie

"Just left there" What you going on about? Wherever possible I try to leave as much copper as possible since this speeds up the etching process.

 

it doesnt matter i shall jst use paint shop pro to resize the image. Does anyone know any good sites for beginners to explain the basics of electronics thanks im only a beginner and havent studied much into electronics but im really eager to get started.

 

Hey, macroman...
i've constructed your circuit but it doesn't seem to respond to HDD activity....if i disconect it from motherboard nothing lights up...if it's connected , however, it lights up but LEDs don't move at all..
i can adjust VR3 so NONE of the LEDs are lit.....i also can adjust VR2 so ALL of the leds are lit...but it just stays this way....NO MOTION...i also tried simulating constant HDD activity by shortening pins 4,5 of opto-isolator...doesn't help...they just stay lit in whatever position they were adjusted...
PLZ..any suggestions...

 

Just Received My Parts

Hi All,

I just received the parts need to make the cool knightrider mod, all the part apart from the PCB kit from maplin that is so can't start the mod yet, but wanted to know if anyone else has made or going to make this with the maplin £17.99 kit. Or if not with this kit then just in that way i.e. the pen thing. Also will be in norwish next week so will go into the maplin store and get the sockets you used Macroman are they these ones Here.

Bulb66

 

Hi all and gongrats on a stonking forum, its been many years since i made my own pcb and this circuit got my as* into gearand i built it that was the easy bit,

now on power up i only get no 1 led lit if i put it into ding dong mode with the jumper then they all light up but no movment.

resistanse accross pins 2 and 4 is around 5k and i cant get it any lower although i read that it sould still work.

and voltage at pin 3 of ic1 is around 6 v

im a bit stumped now i have tested all my connex and all would seem to be fine.

any ideas b4 i make another pcb and start again



sorted resister settings cool curcuit.

thanx for the forum chaps you have cheered my wife up no end

 

Good Job...

Always doing a good jobs with the mod

 

Hi all guys... i'm form Venezuela and this is my first day with Broadband and my first post on this forums!!

Im glad to hear your projects worked well, but can you please helo me to get mine to work?

y first use the protoboard... and made it twice and still the circuit leds just stays lit, when i turn the pots i can scale all lit in bar mode, but both pots (10k and 4k7) do the same thing. i turn 220k pot up and down and nothing happens,... i took it off the board and the circuit still makes the same ..
and i have a few more question, considering i got bad IC's..

how do i test the ICS with a multimeter ¿?

thanks for all help you can bring me :$ and sorry about my english... im spanish native :$!!