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LED in parallel to power?

I have a project and i am wondering if you can hook up a diode to the power source (hook it up in parallel to it) would you have to hook it to ground in some way??

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Power dissipation = current x voiltage drop. Thus 2v x 0.02 A ... or 40mW.....
HTH
Steve
astroboy907 (author) 7 years ago
To All,
Here is a (simple) schematic i made of it. It is for a small dc to dc power converter (similar to mintyboost). I wanted to have an led to tell weather it was on or off. It is a 603 SMD led, with a resistor (which should be somewhere around 100 ohms) would i have to get a high wattage resistor? or because it is in parallel could it be smaller? I am also a little confused about how to wire it (see schematic)

We need to know the supply voltage, and the LED type to comment further.

Steve
astroboy907 (author)  steveastrouk7 years ago
is there a schematic on it? hmmm... will try reloading
The led is a 0603 SMD LED, and the resistor is also 0603. Both can be changed if necessary.
Untitled22.jpg
The "Or this" diagram will work. The first is completely redundant, because you have shorted out all your circuit !
astroboy907 (author)  steveastrouk7 years ago
k :)
Thanks! I just have 1 more question, should i get a 2.5 (or greater) wattage resistor? just in case. oh + if you were wondering i switched all my parts to non SMT :)
Also, will there be any significant power loss??
Power dissipation = current x voiltage drop. Thus 2v x 0.02 A ... or 40mW.....

Steve
astroboy907 (author)  steveastrouk7 years ago
can you post this as an answer?, then i will pick u as best
AndyGadget7 years ago
If you're talking about a low voltage DC power source, it needs to have a resistor in series with the LED.  There's a calculator for the value HERE.
If it's a normal LED, enter 20mA for the current, and the forward voltage should be written on the pack they came in or in the advert you bought them from - If not, use 2V.
If you want to connect to AC or to over 12V then things are a little more complicated - Let us know the details.
HAVE to have a resistor with it.

Steve
Re-design7 years ago
Ground is just another name for NEGATIVE (usually).  So just hook that led up to the pos and the neg with any required resistor and away you go.