Inside Lamp and add relay in starter connection

[SuperDuper]

after tat will like the BMW car loh, closed d door n it will slowly goes out instead of straight away lo!! :lol:

 

[jkn]

Yes, this is what I'm trying to do! But I'm gonna add much more lighting coz the ori light is useless.

So I just put all the cap(s) in parallel can oredi right? Then serial connect potentiometer to my LED array. Does that sound right?

Another way I was thinking was to use dual opamp and can adjust the fade-up/fade-down levels, but I'm starting to get headache oredi
Anybody done this before?

Thanks for your advise.

 

[jkn]

Oh yeah... any advice what caps to use to get 5-sec fade for 10-LED parallel array?

Thanks B)

 

[SuperDuper]

yeah, any1 know wat kinda d caps 2 use ah? n wat is 10-LED parallel array anyway? :blink:

 

[jkn]

10 LED parallel array is 10 LEDs connected in parallel :P


Hey guys, where can I get my components and wiring from?

Any shops near OKR?

Thanks

 

[SuperDuper]

oh.... but y need 10 LEDs?

 

[differ]

hmm, to clarify some things...

a relay is nothing but a switch, plain and simple. a basic relay has 5 legs - P, N, NO, NC and C.

P-Positive
N-Negative
NO-Normally Open
NC-Normally Closed
C-Common

Positive and Negative is basically the trigger for your switch. It's a coil that magnetizes when Direct Current is passed thru it. This magnetic effect then pulls the switch's "Finger" which is connected to Common.

so if you want it to ON when DC is passed thru the coil, you then connect the circuit you want to turn ON to legs C-NO.

if you want it to OFF when DC is passed thru the coil, you then connect the circuit you want to turn ON to legs C-NC.


BUT...


what you want to use here is a Capacitor. a Capacitor is basically a device that you use to store energy.

cook up a simple RC circuit (Resistor-Capacitor) and that'll solve your problem.

the kind of Capacitor to use (how many microFarads) depends on how long you want the Capacitor to discharge.

basically the ideal equation is this:

Q1 = Q0 x [ (e)^(-t/RC) ]

where Q0 = C x V0

V0 is your voltage across the Capacitor when fully charged in Volts
C is your Capacitance of the Capacitor in Farads
R is your resistance of the Resistor in Ohms
t is time in seconds
e is the exponential base constant = 2.718

so to find out what capacitance to use, you ask yourself how much time you want to give the Capacitor to discharge. fill in that as 't' and also the rest of the values.

then Algebra a little and voila!

of course this is the ideal case but in the real world you can just go to an electronics shop and tell the uncle what you want to do and he'll probably pick out the right components you need.

:lol:

 

[SuperDuper]

wah! must be a engineer or somethng u r? quite lot of math u doing there.. hehehe :) but quite infomative la, hehe!

 

[differ]

General Physics 101 - Inti College Malaysia '97

:lol:

 

[jkn]

Right!

So where can I get the components? I just moved to KL so I dunno any shops yet. Any recommendation where the owner is helpful? Thanks.

I need some caps, resistors, potentiometer, breadboard, light and heavy gauge wires, wire plug/sockets, captive switches, wedge bulbs and sockets. :rolleyes:

Oh, about capacitors: They will only charge up to the voltage supplied right? So if the cap volt rating is higher than the supply, there should be no problem right? I dowan my caps to suddenly discharge 16v into LEDs :P

Thanks!

 

[Jackal]

so how to noe how much voltage? anyone can give some idea :P izzit all the car is same?

 

[differ]

for Electronics in KL, you always go back to the mothership called Jalan Pasar.

capacitors will charge up until the potential difference (Voltage) across the capacitor is equal to the potential difference across the battery, in our case 12V or so.

fyi, when the capacitor is fully charge, there is no longer current flowing in that circuit.

yes, the capacitors should not charge up more than the voltage supplied because the potential difference btw the two must be zero... everything in life must be balanced, always the middle ground. :D

 

[jkn]

Originally posted by differ@Feb 19 2005, 15:44
fyi, when the capacitor is fully charge, there is no longer current flowing in that circuit.

:o

So my LEDs will fade UP as well as DOWN?

Anyway, guess I just have to experiment.

I'll post up new topic with pics when I'm done, k?

Wish me luck.

 

[differ]

connect the LED in parallel with the Capacitor.

 

[SuperDuper]

but can it use with d round light tat they usually change in d car ah?

 

[jkn]

I'm making mine as a direct drop-in replacement for the bulb in my Kelisa.

 

[SuperDuper]

direct drop-in? wat is tat?