Voltage (and current) regulators
Related: hacks
Some regulator test boards
A natural and useful part as well as a necessary evil in many projects, power supplies come in many shapes and sizes. Sometimes you have supplies that deliver a voltage you can use, but having DC-DC converters, filters, or regulators will expand the selection of supplies you can use.
Proper power, EMC, and regulator design requires considerable attention and results will need some pretty advanced measurements. A prototyper can still get lots done with fairly simple bits and modules using quite safe voltages and currents. Some of these quick hacks can be further refined into real designs. Some will perhaps be replaced by off the shelf supplies once they are available.
Lab supplies are fantastic on the bench, but they can't often be used in other conditions.
Voltage regulators are often usable also as current regulators or constant current sources. These are in particular used to drive semiconductors such as LEDs and lasers as well as linear battery and capacitor chargers.
I've been messing with various regulators for other projects. I'll try to put up some links and notes.
Parts
Handy parts to know:
- 78xx series linear regulators
- LM317 adjustable linear regulators
- AMS1117 pdf adjustable linear regulators
- TL431
LM/TI Simple Switchers are perhaps outdated, but very available and indeed simple. I've thrown together some LM2575 based ones on the spot as cooler running or higher current switch mode alternative to the linear LM78xx/LM317 type designs. Adjustable ones are also commonly sold as modules and there are both buck and boost (and maybe other, depending on design) types.
Relatively slim but beefy KIS-3r33s buck modules based on MP2307 (pdf) are cheaply available on ebay and many (Chinese) net stores.
"ultra small" module
Several sellers on AE carry these. The descriptions may be way off (like this one has nothing to do with LM2596 or zener diodes).
This is still one of the neater ones. I think I looked up the chip, but I should get the links here as well. At roughly $.50 a piece, these are truly cheap and cheerful.
KIS-3r33s
Cheap and cheerful switcher. Inside is an MP2307, coil, diodes, and a few bits.
- Fixed 340 kHz frequency
- 3 A continuous output current
- 4.75 V to 23 V operating input range
- Output adjustable from 0.925 V to 20 V
- Module output preset at 3.3 V
LM2575
Simple switcher indeed. An old chip, but commonly available.
- Fixed and adjustable versions
- 1A for 2575T
- Up to 40 V input voltage
- Fixed 52 kHz frequency
- Large-ish inductors because of the low f
Links
- Adafruit on power supplies
- Linear Technology makes fantastic chips, notes, and tools