3-terminal adjustable linear regulator
2
votes
7answers
1k views
Controlling high output LED's with a microcontroller
I'd like to build a circuit to precisely control the current through a couple of (LED and laser) diodes. I would like to minimize the number of components if possible. Power consumption is not a ...
1
vote
1answer
2k views
Dual polarity vs dual rail power supply
My previous post turned out to contain too many questions, so I'll focus on the main one first, and figure the rest out as needed.
I'm looking at building a DC lab power supply, roughly 1.2-14 volts ...
6
votes
4answers
974 views
LM317-based adj power supply output takes a while to stablize
I recently built-up a quick little LM317-based adjustable power supply schematic:
However I've noticed the output can take several seconds (on the order of 10 or so) to "settle down" after turning ...
4
votes
6answers
859 views
What's causing this high frequency ripple on the output of my LM317?
I'm using an LM317T to regulate 5V to 3.38V for a microcontroller. R1 is 330 ohms and R2 is 560 ohms. There is no input capacitor and the output capacitor is a 470µF 25V, because I had that value in a ...
3
votes
1answer
2k views
Simple LM317 variable voltage supply, does it limit current too?
I had wanted to build a power supply for so long, and had never really understood the calculations involving the LM317. I had found a kit (pcb+parts) online and it had renewed my interests in using it ...
3
votes
4answers
2k views
Resistors values to use with LM317
I know that ratio R1 to R2 determine the output voltage of LM317. E.g. R1 = 200, R2=330 ohms will produce about 3.3V. My question is, what if I use 2K and 3.3K for R1 and R2? What is the impact of ...
1
vote
4answers
4k views
LM317 to create constant current of 2mA?
I have a circuit where I want to have a constant current of 2mA through a variable resistor. I've been told that I could probably use a LM317 as a current regulator, with one resistor on the ouput. ...
