Hi all!
I recently became interested in building electronics, and I have a question about having an LED and a switch in parallel.

I built the following circuit in a program called Yenka:

My question is, since the LED is parallel with the switch, why doesn't current flow through the LED regardless of the state of the switch?

 

Hello,

The voltage accros the led is dependend on the color of the led.
Red and green leds need a lower voltage to work than blue and white leds.
Blue and white leds probably will not work at 3 Volts.
See the table on the following page:
http://www.oksolar.com/led/led_color_chart.htm

This is a page from the EDUCYPEDIA in led technology:
http://www.educypedia.be/electronics/composemiconductorsled.htm

Greetings,
Bertus

 

thanks for the response, and useful reference material =)
however, the LED gets 0amps when the switch is pressed, and I'm still unsure why that is

 

Hello,

When the switch is closed, all the current will go through the switch as its resistance is much lower as the leds resistance.
When the switch is opened the current will flow through the led, if the led voltage is lower than the 3 Volts.
The currrent will be (3 - Vled) / 100, in your case.
If the led voltage is higher than 3 volts, hardly any current will flow through the led.

Greetings,
Bertus

 

ahhh, of course!
Thank you, I must not have been thinking straight =/

 

Hello,

The website I gave you also has a page with led circuits:
http://www.educypedia.be/electronics/circuitsled.htm

Greetings,
Bertus

 

I've used voltage dividers to turn an LED off before, it used more wattage, but it was very similar to your concept. I explained it in this article I wrote a while back (and is still a WIP).

LEDs, 555s, Flashers, and Light Chasers