switch/led problem

[birt]

i wired a led to a stompswitch. like i've done a couple of times before, everything is ok.
i put a battery in, it lights up as supposed to.
i switch it of, and then on again and the led was broken.
thought it was a bad led, the second led went the same way.
and i'm sure i've wired it correct.

WHAT THE F***?

[blacksnake]

salut

pour que tu puisses connecter une led il faut ajouter une résistance à la source +9V sinon la led cramera. j'ai fait un programme dispo sur mon site

egraffin.free.fr/electro.php

[birt]

salut

pour que tu puisses connecter une led il faut ajouter une résistance à la source +9V sinon la led cramera. j'ai fait un programme dispo sur mon site

egraffin.free.fr/electro.php

je sais, mais ca ce n'est pas la (le?) problème.
je pense il y a un court circuit (i hope this is the right translation of a short) quand je puisse.
i think it's the switch itself
:lol:

[birt]

i used the other side of the switch for the led.
the problem is solved now but i still think it's weird

[niftydog]

how exactly was the switch/LED wired? It could be that it's a make before break type of switch and there's a short circuit there somewhere for a moment inbetween the on and off states.

[gez]

Are you sure you weren't reverse biasing the LED when it was kicked out (wiring wrong)?

[birt]

it's a dpdt and i use one side for switching and one for the led.
i didn't change anything to make it work, just moved the led to the other side of the switch

[niftydog]

yes, but what are you actually switching? Are you switching power to the LED or are you disconnecting ground? Where is the current limiting resistor in the circuit? etc etc.

Like this? or something else?

Code Select Expand

+VDC
 |
.-.
| |
| |
'-'
 |
 |
 V
 -
 |
 |
 o
  \
   \
 o  \o
 |   |
 |   NC
===
GND

NC = not connected

[birt]

it's:

+,led,resistor,switch,-

[vanhansen]

Shouldn't it be:

+9V ----> resistor ---> LED ----> switch

The resistor should be between the LED and the incoming voltage to "limit" it so the LED doesn't fry.

Check this out on GGG:
http://www.generalguitargadgets.com/diagrams/switch_lo_dpdt_led_in.gif

[toneman]

LED, resistor
or
resistor, LED

it's electricity.
doesn't matter the order.
DOES matter that it's *actually* 9VDC,
and not a "9V adapter" which is usually greater that pure 9VDC.
With "pure" 9VDC, smallest resistor is 680ohm.
T

[niftydog]

...and the other terminal of the switch in not connected to anything?

I'm thinking wrong resistor size or incorrect voltage, like toneman says.