Question about LM317 IMPORTANT!
I made a huge mistake in the drawing of post #23.
Please forgive me and disregard that drawing.
The correct one is this one, below. Grateful.
Monday, 17 January 2022 - 00:43
Question about LM317 avrcandies wrote:
With 1k on the base & 5V & vbe drop, you are Ok for the source spec of 4ma (you are not using sinking at all).
Your post reassured me,...
Sunday, 16 January 2022 - 23:28
Question about LM317 Who-me wrote:
rmlazzari wrote:
I'd like to add the 5mm LDR at the top of that box.
Keep in mind LDRs are inverse log response, so a smooth linear action will be hard to...
Sunday, 16 January 2022 - 21:23
Question about LM317 They say that a picture is worth a thousand words.
Well... sorry for the slightly blurry images, a new cell phone is about to arrive.
Here's the lamp. The LED that shines...
Saturday, 15 January 2022 - 01:34
Question about LM317 avrcandies wrote:
Use a photodiode instead (more sensed light---> more photodiode diode current)
I didn't know that device. I'd like to use what I have here, in...
Friday, 14 January 2022 - 23:59
Question about LM317 avrcandies wrote:
Are you talking about a 500ma or 1 amp led? Or a 4 ma led?
We are talking about a red led, 20mA, 2.2v dropout, very common, and that, if the...
Friday, 14 January 2022 - 23:49
Question about LM317 grohote wrote:
rmlazzari wrote: wish to set 317 using variable resistors (like LDR ou thermistor).
You can use Thermistor as R2 in #4 picture.
As for LDR, you can try with...
Friday, 14 January 2022 - 17:29
Question about LM317 The datasheet recommends to use a variable resistor as R2. It means as greater is that resistance R2, greater is Vout. I'd like the opposite: greater resistance, less output...
IMPORTANT! I made a huge mistake in the drawing of post #23. Please forgive me and disregard that drawing. The correct one is this one, below. Grateful.
avrcandies wrote: With 1k on the base & 5V & vbe drop, you are Ok for the source spec of 4ma (you are not using sinking at all). Your post reassured me,...
Who-me wrote: rmlazzari wrote: I'd like to add the 5mm LDR at the top of that box. Keep in mind LDRs are inverse log response, so a smooth linear action will be hard to...
They say that a picture is worth a thousand words. Well... sorry for the slightly blurry images, a new cell phone is about to arrive. Here's the lamp. The LED that shines...
avrcandies wrote: Use a photodiode instead (more sensed light---> more photodiode diode current) I didn't know that device. I'd like to use what I have here, in...
avrcandies wrote: Are you talking about a 500ma or 1 amp led? Or a 4 ma led? We are talking about a red led, 20mA, 2.2v dropout, very common, and that, if the...
grohote wrote: rmlazzari wrote: wish to set 317 using variable resistors (like LDR ou thermistor). You can use Thermistor as R2 in #4 picture. As for LDR, you can try with...
The datasheet recommends to use a variable resistor as R2. It means as greater is that resistance R2, greater is Vout. I'd like the opposite: greater resistance, less output...
Thank you, everybody!