Reddit reviews RioRand 3-01-0076 Buck Converter (Step Down Module Power Supply Output 1.23V-30V (1Pcs-LM2596), LM2596 DC)

You don't want a voltage divider, that's a pretty specific circuit made out of resistors ;)

I've found these little devices pretty handy for running things off a 12V supply. They're limited to 3A, but with a little bit of wiring you should be able to run them in parallel... tweak both of them to the exact same output voltage on your multimeter, then wire them up in parallel, throw a 100uF cap across the output leads to help filter the supply, check the voltage, and you're set. Once the rig is running to your satisfaction superglue the pot screws so they don't get turned accidentally.

Equipment

• Nexus 7 2013 w/ Timur's kernel (still in closed beta - open for donors)
  
• Custom 3d printed housing
  
• Alpine KTP-445U 4-channel Power Pack Amplifier
  
• USB OTG Cable - Modified to fit
  
• DC-DC Converter
  
• Behringer UCA202 USB DAC
  
• Bluetooth OBD2 Adapter - For getting real-time data into the Torque app
  
• Add-a-fuse
  
• Ground loop isolator ** Item still needs to be tested. This was purchased to hopefully eliminate a popping noise i get when first powering on the system
  
  Must Have Apps
  
  
• GMD Gesture Control - Since i have no physical volume control buttons anymore GMD gesture control allows me to setup custom gestures like a 2-finger swipe to access volume control.
  
  Very excited to be ~95% complete with the install. A couple things left:
  
  
• pull out the double-din housing i made and put the top on it which also includes a fan
  
• address a 'popping' sound when turning on the system. possibly caused by the amp turning on before everything else? still seeking a solution here
  
  More than happy to try to answer questions for anyone else looking to do the same thing. Very happy with the outcome thus far.

This is very close to what I've was working on for a very long while and gave up. I just don't have the programming kung fu. I would love to get back on it as I've got the hardware down just the damn programming kicked my but.

here is a picture of what I trying to achieve.

the ramp and the numerical display

and I just wanted to press a button to toggle between the different sensors. I sorta got the ramps working but I couldn't get programmed how to get the ramps to show different sensors at a button push.

Maybe we can work together or maybe a peak at your code to give me a hint on how to proceed.

Edit: by the way after calulating the amp draw I decided to use one of these to power the sensor as it's more stable and cleaner for my install needs.

Yes. Use a 24vdc power supply with 6+ amps and then use a buck converter to drop the 24v to 5v.

Buck converter

Power supply

A few of my own:

• Expanding on /u/mc2222's field battery idea:
  
  A great many things...including things you might not otherwise think of...can be powered by a 12V DC power source, such as a car battery.
  
  Swing by Wal-Mart, and check out the Deep Cycle "marine" batteries. They're pretty low quality for marine needs, but they're perfect for ours. Even a mere 50AH of capacity will be PLENTY for what we do. You can pick one up for $40-$80 depending on size/capacity.
  
  Next, look for or build some sort of distribution panel/box/etc. It can be as fancy or plain as you want. All you're after is some central point so you can plug in all this stuff you never knew could be powered off 12V. Personally, I use this guy but there's lots of other methods of doing this.
  
  Now...there's all the obvious things you can power with it. Most motorized mounts, for example, plug right into the car lighter outlet. You can, of course, clip that connector and put some other connector (like the banana plugs my unit takes) on if you wish. But for these items, no further mods are necessary. Dew heaters and camera coolers are other common 12V devices.
  
  Now here's where we get cute...Got a DSLR? It probably has an AC Power Adapter available for it, right? Take a close look at the specs for it...you'll see that while its INPUT is 120VAC (plugs into a wall) it's OUTPUT is plain ole DC...PROBABLY 7.2V or so (a 2 cell LiPo, for the record). Grab yourself a little adjustable step down gadget, cut the cable on the CAMERA side of the converter that's inline, and just use the handy battery adapter piece. Solder it up to the output side of your step down supply, solder up some wires on the input side, set it to 7.2 (or whatever) output, and poof...12V power for your camera. :)
  
  You'll find there's a zillion devices that "plug into the wall", but if you check their OUTPUT, it's 12V DC (or less)...and thus, you can use this method to power them in the field off your field battery. :)
  
  
• Hand Warmers : Not only good for keeping hands toasty on cold imaging nights, but useful for keeping your guide scope or camera lens warmer to help ward off dew/frost.
  
  
• HobbyPartz (among many others, but these guys are amongst the cheapest I've found) has these slick Red LED strips that can be powered by as little as 3V, or up to 12V. They use insanely low amounts of power, so even a small battery pack will power them all night.
  
  What good are they? Well...they're adhesive on the back, AND you can cut them to your desired length, and solder new lead wires onto each strip. Viola...you've got night-vision safe lighting for your laptop, your telescope, your field table..whatever! They serve both to illuminate your work area, AND mark your equipment for others' safety.
  
  

Even a 9V will run out of juice eventually, unless you're talking rechargeable. You could also just buy rechargeable AAAs.

Back of the envelope calculations for average alkaline batteries - 9V batterries have ~5.085Wh, 3 AAA's have ~2.58Wh. To step 9V to 3.5V (3 AAAs in series), you'll have efficiency losses in the best case of ~80% with a buck regulator or 4.068Wh and the worst case with a linear regulator (3.5/9) = ~38.9% => 1.98Wh. So in the best case you'll get a 4.068/2.58 = ~1.58x increase in battery life with a 9V, for the added cost of a buck regulator.

I have found myself needing this board on multiple small solar projects.

http://www.amazon.com/RioRand-LM2596-Converter-1-23V-30V-1Pcs-LM2596/dp/B008BHAOQO/ref=sr_1_3?ie=UTF8&qid=1459357250&sr=8-3&keywords=dc-dc+down

http://www.amazon.com/LM2577-Adjustable-Step-up-Converter-Module/dp/B008HMETBE/ref=sr_1_1?ie=UTF8&qid=1459357283&sr=8-1&keywords=dc-dc+up

these are the same design step up/down converters I used. some brands spec them to 2 amps, some say 3. the spec for the chips says 3 amps, but I would attatch a heat sink with thermal epoxy.

notice each of the boards has a small pot soldered to the board, this is to adjust the output voltage. the adjustment is so small its a pain to change so I removed those small pots and used the 3 panel mount pots you see (the dials). double check that the pot used on these boards is 10k. all mine were, but make sure. any 10k pot will work, but you should get one that is multi turn. the pots I used are 20 turn, its a little much to go from 1.2v to 19v. but will probably be just right going up to 30v.

http://www.banggood.com/DC-0-100V-0_36inch-LED-Car-Auto-Voltmeter-Gauge-Voltage-Display-Volt-Panel-Meter-Monitor-Voltmeter-p-992875.html
these are the volt meters I used. they are pretty decent. 2 were spot on, 1 was off by .2v. there is an adjustment on the board if you get any that are off.

http://www.banggood.com/3A-15W-DC-12V-To-DC-5V-Dual-USB-Power-Charger-Adapter-Converter-Module-p-930992.html

this is the usb power converter, I cut the usb ports off and connected the wires to a usb bracket that was made for adding usb ports to a computer connected to the usb header on a motherboard.


http://www.amazon.com/Bluecell-Plastic-Speaker-Terminal-Amplifier/dp/B00UHFF2ME?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

these are the banana plugs I used. If you mount them to metal, make sure you insulate the posts, there is no grommet. I used 2 layers of heat shrink on the threads and make sure the metal was not sharp.

the knobs I found at my local shop. I suggest getting pots that have a shaft larger than 4mm. its not that easy to find large knobs that are for 4mm shaft. I ended up shimming my 4mm shafts with some rubber.

This thing is the most efficient way to do it

If it is a prototype or a "one of a kind" use, i would go for a Buck converter module.

Relatively simple option: get a buck power supply and connect the fans to them.

Something like this for instance.

Note that it has a minimum voltage drop.

pot adjustable buck converters, for projects that have a constant power source, they work great.

but like i said i haven't tested them with batteries at all.

https://www.amazon.com/gp/product/B014Y3OT6Y/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B008BHAOQO/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

LM2596 3 amp

http://www.amazon.com/gp/product/B008BHAOQO/ref=oh_details_o06_s00_i00?ie=UTF8&psc=1

I used a LM2596 DC-DC Buck Converter Step Down Module Power Supply Output 1.23V-30V on my first one.

http://www.amazon.com/gp/product/B008BHAOQO/ref=oh_details_o06_s00_i00?ie=UTF8&psc=1

For me it works great, I like it better than my vamo v3 but someone suggested for my next build I use an okr. I don't really know much about them besides what I've gathered here.
Anyway I'm sure it's better but what are the benefits to the okr t10 compared with the buck converter. BTW I'm planning on using 2 18350's and carving a wood box with sorta a pistol grip that fits in my hand really nicely.

Thanks

Even though the picture of my box really doesn't have anything to do with this but I'm proud of my mod, nothing special but you know how it is.

Assuming the by RAW port, you mean the VIN port, you're already likely using a 7805 that apparently has a current limit of 200mA. Assuming you're driving the LEDs directly from digital pins, using I = V/R you can roughly calculate the current you're consuming, where V is 5, and R is the value of the resistor in series with the LED. This will calculate the current consumption for each LED. Note that while the total current consumption shouldn't exceed 200mA, the total current consumption per pin shouldn't exceed 20mA. In fact, for the pro-micro, the recommended per pin limit is 10mA.
If you need to drive some additional current, the solution is to isolate the signal from driving the LEDs. Using a darlington array (like a ULN2003) is a simple solution. Then upgrade the dc supply with a buck regulator like this, and adjust the output to 5V(or 3.3V if it's a 3.3V version) , and connect the output directly to the Arduino's 5V rail (or 3.3V if it's a 3.3V version).

You could always do the opposite and remove the battery, then power with something like a LM2596 DC-DC Module, something like:

http://www.amazon.com/RioRand-LM2596-Converter-1-23V-30V-1Pcs-LM2596/dp/B008BHAOQO

I did that on one of my 10 inch tablets, and mounted the tablet to a monitor swing arm, works perfect, just adjust the LM2596 DC-DC Module to what your battery was putting out.

On my 10 inch tablet I had the LM2596 DC-DC Module set to 5v, and ran another 5v+ wire from the LM2596 DC-DC converter to the USB connector, I ran this extra wire so the tablet believes the battery is charging, if not the tablet will try and shutdown because it thinks your battery is draining.

Aliexpress - Car Charger DC Converter Module 12V To 5V 3A 15W with Micro USB Cable

Amazon - RioRand LM2596 DC-DC Buck Converter Step Down Module Power Supply Output 1.23V-30V (1Pcs-LM2596)

For powering from the 7.5v, I used a buck converter from amazon: https://www.amazon.com/RioRand-LM2596-Converter-1-23V-30V-1Pcs-LM2596/dp/B008BHAOQO

I ordered a few, they're really simple to use, just solder onto the input voltage holes, plug in the PSone adapter, and with a multimeter attached to the output voltage holes, adjust the little screw on top of the blue box until you read ~5VDC.

The video pinout is here: http://www.gamesx.com/avpinouts/psxav.htm

Bear in mind: it's possible to output a full component video signal to the PSone screen if you use an HDMI to component video converter. If you don't want a separate HDMI output then that might be a good way to go. Otherwise, wire the video to pin 6 and solder the screen's board the way I did to get the screen to show video.

I'll make another post for the PSX controller. The whole article for setting up the GPIO is very bad. It's also buggy...I'll get into that.

I'm assuming that the light bar is hardwired into the vehicle, so a good place to start would be to figure out what voltage its operating at, then look up relays. You can use the zero to control a relay to do the switching for you, but you'd also have to add blue-tooth capabilities to your zero in order to remotely control it.

There are also relays that have blue-tooth built in.

Both the zero and blue-tooth relay will need to be powered with 5v from somewhere. If you're going to do that from your vehicles 12v system (making assumptions again), you'll need to look into a step down power converter. Or some kind of battery pack that will last you all day.

All of these things will require at a minimum a voltage meter for probing your power inputs and outputs (don't want to fry anything) and basic soldering skills / equipment.

edit: words

Yea, I'll give that a try.

I just checked out your buck converter (I think it's this one) and it says the max current output is 3A. Odd (but good for you :D ) that you're not running into any problems.

I'm not sure if I completely understand the zener regulators but it seems to me as though the power consumption of simple one is going to be wildly high with such a large difference between input and output voltages.

Perhaps if I can ensure the voltage does not jump too high and the current demands are low enough one of these switching regulators will work well: https://www.dimensionengineering.com/products/de-swadj3

Too bad they're fairly pricey.

Edit: Better yet something like this: http://www.amazon.com/RioRand-LM2596-Converter-1-23V-30V-Pcs-LM2596/dp/B008BHAOQO

I use a 2kw Honda generator for emergency charging through a 20amp marine battery charger and for running the large power tools. I built a DC generator for every day charging using a Harbor Freight gas engine and a 40 amp car alternator. I have two Walmart deep cycle marine batteries which are adequate but not very long life, eventually I'll replace them with four Trojan T-105 golf cart batteries. It's critically important not to discharge them more than 50% nor to let them sit partially charged any longer than absolutely necessary. To keep up on charge state I very highly recommend a charge monitor like this.

I have not built my solar system yet but will be using two to three 250 watt panels with a midnight solar MPP charge controller. I use very little AC power so a small Xantrex 600 watt sine wave inverter is sufficient.

I am wiring my cabin with two AC circuits and a few DC outlets, all lighting will be DC LEDs (as in these with small dc/dc power converter boards, I put eight of these in my boat and have two in the camper for the time being, lots of light and only 90ma ea). I haven't decided how much AC I'll be using but I've used DC exclusively for the last year in my 22' camper as I get my site ready to build. I am using an RV fridge that runs on propane and a Mr Heater 18kbtu propane heater, I pay about $25 a month for propane and that will balance out in summer when the fridge takes more to cool and the heater isn't used.

I do not see the need for large inverters unless you come across one used that also contains a large marine (3-stage) battery charger - if I had one I wouldn't use the DC generator as much. I don't run microwaves or electric appliances, just a small tv and small loads that are quick to charge like a Nintendo DS, iPhone, mp3 player and tiny speaker system.

Passive cooling with shade trees and wood fired heating are best if you're off grid. Controlling demand is easy once you get used to it, you do not need a big inverter and in fact they waste a lot of power when they're searching for a load so you're better off with small ones.

Oh and wire to hook it all up is expensive, I use this which is a fraction of the cost of marine stores, it's welding cable so it's practically burn proof and it's extremely flexible. You just need a big hot torch to solder lugs on it because the bare copper conducts the heat away quicker than tinned wire does.

Good luck.

Edit - these Astroenergy panels are what I'm considering, this vendor seems to have good prices at least on panels.

For my project I used the LM2596 at first too. But the load i used (2A at 5V) heated up the converter way too high for my taste. So I bought a pretty overpowered but higher quality and more efficient step-down module. I'm very happy with it, because it doesn't get warm at all.

I am building a proof-of-concept/prototype at the moment. Once I cobble it all together and confirm that it works, I will have to pay someone to design everything into a single PCB.

I was leaning towards this solution for the prototype:

12V 6A AC Adpater

LM2596 Buck Converter

Holy balls, for a buck? I wouldn't trust it...

What about some of these off of amazon? I just searched for LM2596.