Blue LED for BOSOZ, how to implement?

[Yochim]

I am just about finished with my BOSOZ but I would like to have a blue LED on the front panel.

Should I take a feed off of the power supply rails to the LED? If so should I use a resistor in front of the LED?

Thanks for any info.


Y.

 

[fcel]

Those blue led gets very bright. I suggest to start with a 200K resistor in front of the led. I remember someone on this forum install two leds - one on each rail - just so that it "looks balanced electrically".

 

[Yochim]

fcel, thanks for replying. Do I connect the LED directly to the power supply rail?


Thanks.



Y.

 

[AudioFreak]

If you want it to be balanced electrically, connect it across the +ve and -ve rails (instead of +ve to gnd) and double the resistance.

 

[Peter Daniel]

If you want to do it really well , put some extra turns of thin wire on your toroid and conect LED there with a small resistor.

 

[jh6you]

Waoowww...!

It's a fantasitc idea. Clap! Clap! Clap!

JH

 

[jh6you]

Yochim

I like the way as in the figure.
You could install LEDs of as many as number of diode bridges.
You could make them by easy p2p wiring.

JH

 

[skaara]

You dont even need a bridge for led

 

[stefanobilliani]

You may protect the led with 4 1n4004 series across its pins.
This metod limits the voltage at 2.5 volts or so.

 

[skaara]

But diodes will get hot, especially at that voltage?!

 

[stefanobilliani]

 

[stefanobilliani]

This helps you when you play with resistor values.
Is a protection if you decide to put the led in parallel with a resistor in a PI filter. There , the the turn on voltage values may go as high as 6 or 7 volts
and so the led is protected.

 

[stefanobilliani]

Oooops...

 

[jh6you]

Hi, Friends

I have the diode bridges between the transformers and
the PS capacitors for my BOZ and Zen V2.

I just read the reference AC supply voltage at the bridge position,
e.g. 24V AC in case of my Zen V2. Meanwhile, my blue
LED lightens lovely when about 5mA currents flow thru it.
Therefore, I calculate the necessary resistor value in this way:
24 x 1.414 / 0.005 = 6787, i.e. about 7.5K ohms (watts?
24 x 1.414 x 0.005 = 0.17w).

In the same way,
if the AC supply is 30V, R of about 8.5K and
if 40V, R of about 11.5K and
if 50V, R of about 14K and
if 60V, R of about 17K...

If we know the AC supply value and the necessary current thru
LED for a lovely light, we can calculate the necessary resistor
easily. Try it.

JH

 

[skaara]

stefanobilliani, i thought you would connect this without resistor, my mistake

 

[HarryHaller]

How many DIYers does it take to change a light bulb?

I saw the light, I saw the light
No more in darkness no more in night
Now I'm so happy, no sorrow in sight
Praise the Lord, I saw the light

 

[skaara]

seven.

 

[paulb]

Should I take a feed off of the power supply rails to the LED? If so should I use a resistor in front of the LED?

Nobody answered his questions.

Yes. Yes.

Calculate R =
[(power supply voltage) - (LED voltage)] / (LED current)

Calculate power of the resistor =
[(power supply voltage) - (LED voltage)] * (LED current)
Double this (at least) to get a power rating for the resistor. You can put a bunch of resistors in series to use smaller-power resistors.

LED voltage, current are about 3V, 5 mA (look up the specs of the LED). Tweak resistor value to adjust brightness.

 

[HarryHaller]

Does anybody know how to do this with a green LED?

- removed obnoxious / rude / abrasive comment

editted by moderator.

 

[Peter Daniel]

This could be more complicated because of a different voltage drop.