### Author Topic: high voltage  (Read 1577 times)

0 Members and 1 Guest are viewing this topic.

#### jorj

• Jr. Member
• Posts: 34
##### high voltage
« on: July 21, 2009, 04:16:44 PM »
I build an electricl circuit, the circuit is source of current of 320 mili ampere
The maximum permitted current and voltage in the luxeon led is
350 mili ampere and 3.4 volt
Indeed the current was constant after I connect the supplier
But the voltage vary and arrive to 12 volt
Why the led not burn ?
How this circuit work ?
« Last Edit: August 18, 2009, 02:43:29 PM by jorj »

• Robot Overlord
• Posts: 158
##### Re: high voltage and the led don't burn, why ?
« Reply #1 on: July 21, 2009, 05:20:33 PM »
Have you looked through the data sheet you posted? It has several different illustrations on how to hook up that regulator and the circuit you posted isn't one of them.

#### jorj

• Jr. Member
• Posts: 34
##### Re: high voltage and the led don't burn, why ?
« Reply #2 on: July 22, 2009, 03:52:59 PM »
I want to understand how this circuit work
The data sheet is only for help because it  have summarize of LM317

jorj

#### JSM_Xorudd

• Guest
##### Re: high voltage and the led don't burn, why ?
« Reply #3 on: July 23, 2009, 10:25:19 AM »
I believe I'm right in saying the LM317 is an op amp of some sort.

It looks like it's lowering the voltage going to the LED, so that would be why it's not burning out.

#### SmAsH

• Supreme Robot
• Posts: 3,959
• SoR's Locale Electronics Nut.
##### Re: high voltage and the led don't burn, why ?
« Reply #4 on: July 23, 2009, 04:35:51 PM »
Quote
I believe I'm right in saying the LM317 is an op amp of some sort.
the LM317 is an adjustable voltage regulator. it does lower the voltage from the source, yes.
Howdy

#### jorj

• Jr. Member
• Posts: 34
##### Re: high voltage and the led don't burn, why ?
« Reply #5 on: July 24, 2009, 12:34:15 PM »
I don't understand what is this loop
That exit from ADJ and close with resistor that connected to Vout
Did the led don't burn because there is a resistor ?
thanks
jorj
« Last Edit: July 24, 2009, 01:21:12 PM by jorj »

#### awally88

• Robot Overlord
• Posts: 212