Reddit mentions of Nextrox DC/DC Converter Regulator 24V Step Down To 12V 20A 240W Low Voltage Transformer Waterproof

I actually didn't tally up the cost as that wasn't really of a concern to me, but I'll try my best to provide links to the things I bought for this. Feel free to add it up for me!

• Lighting
  
  • T-5 Grow light (came with 6500K bulbs)
    
  • 2700K bulbs
    
  • Grow light hangers
    
• Grow medium
  
  • Net Cups
    
  • Black Buckets
    
  • Black lids
    
• Nutrients
  
  • General Hydroponics Flora Series
    
  • General Hydroponics pH control kit
    
  • pH/EC/Temp Meters
    
• Grow tent
  
• Air ventilation
  
  • The only thing I ended up using from this kit was the cheapest part, the ventilation duct...
    
  • The fan from this kit is way too powerful for my setup because my humidifier couldn't keep up
    
  • I didn't use the carbon filter because I'm not growing weed.
    
• Water Distiller
  
• Humidifier
  
  • The cheaper the humidifier, the better. I first bought (and destroyed) one that had some sort of digital switch, so it would always be in the off state when you first supply power to it, meaning you can't turn it on/off with just a relay.
    
• Plumbing
  
  • Aquatec 8852 booster pump
    
  • 2 Gallon accumulator tank
    
  • Pressure relief valve
    
  • Tubing
    
  • Inline Pre-filter (Sorry they must have taken the product down...)
    
  • Misting nozzle T's
    
  • Tube ball valves
    
  • Analog pressure gauge
    
  • Misting Nozzles
    
    • Note that these nozzles are meant for WAY higher pressure systems (~1000psi) and I actually had to take out the spring for them to operate correctly, but they never clogged up, are easy to clean, and worked perfectly for me!
      
• Electronics
  
  • Raspberry Pi 3 kit
    
  • Humidity sensor
    
  • Pressure sensor
    
  • Water solenoid valve
    
  • 5V 4-channel relay module
    
  • Analog-to-digital converter
    
  • 24V to 12V converter
    
  • 24V Power supply
    
  • Resistor kit
    
  • Semiconductor kit
    
  • Circuit boards
    
  • Standoffs
    
• Wiring
  
  • 22 gauge stranded wire
    
  • 22 gauge solid wire
    
  • Power supply cord
    
• Connectors
  
  • Electronic Connectors
    
    • JST-XHP Connectors
      
    • JST-SM Connectors
      
    • Dupont Connectors
      
  • Plumbing Connectors
    
    • Bulkhead connectors
      
    • Quick-connect kit
      
    • NPT to quick-connect connector
      
      I also bought various tools, like crimpers, Dremel kit, drill, etc, but I don't consider those to be project-specific as I'll have them for the foreseeable future. Let me know if there's anything you see that you think I missed!
      

What you are up against is economy of scale - there is no market for an inverter like that, so there are no low cost (mass produced) ones out there.

You may have better luck getting a 24 to 12V step down and then using a 12V Inverter - I know this is clunky, but step down efficiency is usually pretty good.

After considering our discussion on this I can tell you for sure what I would do if I were in your situation. Since you already have a solar system in place and not starting from scratch you will need a DC-DC switching power supply to replace the AC inverter. I still have never seen one for sale that is suitable for mining so I would build my own to run a single ant s9 based on the design I have tested extensively running 2 ant s5. The design to run 2 s5 is pulling about 700 watts so we need to scale that up to do about 1400 watts. To get right to it these are the parts you'll need, I'll explain in a bit how it will need to be put together and how I came to this design in the first place. After I get all that out I will try to answer some of the other questions folks have about a fully stand alone system. For your needs you will only need the DC power supply/switch/regulator.

2 of these (note it's a 5 pack so you'll be getting 10 relays total. 8 will be used) about $28
https://www.amazon.com/Pack-EPAuto-Relay-Harness-Bosch/dp/B017VDI0GY/ref=sr_1_1?ie=UTF8&qid=1468169603&sr=8-1-spons&keywords=12v+relay&psc=1

1 of these about $70
https://www.amazon.com/Tracer-Tracer1210RN-Charge-Controller-Regulator/dp/B008KWPGS6/ref=sr_1_5?ie=UTF8&qid=1468170133&sr=8-5&keywords=mppt+charge+controller

10 of these about $200
https://www.amazon.com/Nextrox-Converter-Regulator-Step-Down/dp/B00BWKXTUU/ref=sr_1_11?ie=UTF8&qid=1468169653&sr=8-11&keywords=12v+voltage+regulator

Those three items are an mppt charge controller that will be used to control the relays. The 12v relays which will allow you to safely control the power switching and voltage regulators to make sure the power stays clean so as not to damage your gear.

Here's how it goes together, note that all regulators and relays will be hooked in parallel to allow us to get to the desired total amperage;

• DC 12 volt power bus (battery main) gets hooked to the charge controller, powering it up in the 12v range.
  
• Negative bus lead connects to the regulator negative.
  -Positive bus lead connects to relay pass in
  
• Relay pass out 12v positive lead connects to regulator positive.
  
• Relay 'activate power' leads get connected to 'lamp controller' on charge controller.
  
• Regulator positive and negative out connect to miner power cables (pci-e)
  
  Once this is connected as such pressing the orange button on the charge controller front panel will activate the relays allowing power to flow to the regulators which will then even it out and pass it to a secondary bus which will then have the miner power cables hooked to it and power the miners.
  
  By using the lamp controller feature of the charge controller you get low voltage protection. If the batteries get low (even though sounds like you won't have much of a problem with that) the lamp controller will power down the relays and therefore stop the miners. It will automatically reconnect when the battery charge comes back up to safe level.
  
  The idea is to have all this in a box with cooling fans (12v dc case fans) and size it to power a single miner. This box of parts gives you about a 15% efficiency boost over using a big inverter. The cost of an inverter to do this is about $2000, my solution costs about $300, thus dramatically reducing total system costs and allowing a modular approach that will scale while limiting down time due to equipment failure.

I did an amazon search for you: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=24v%20to%2012v%20step%20down%20converter

The first one would be fine.

You will discharge the battery you are drawing the 12V from causing it to wear out sooner. Here is an example of a DC-DC converter that should work fine in your application.

If it is a charger made to plug into an auto cigarette lighter, It is rated for the lead acid voltages. Even during charging of the lead acid battery.

A better solution to have a balance draw from the 24V, is to use a step down converter. You can google for others.

Has anyone ever tried using a 24v power supply and step down the supply to the ramps board with a converter?

I would set it up like this:

Main DC-DC (19-29 V in, 24V out) https://www.amazon.com/uxcell-Converter-Regulator-Transformer-Waterproof/dp/B01N52HIWN/ref=pd_sbs_328_19?_encoding=UTF8&pd_rd_i=B01LWXI4IE&pd_rd_r=3a7d42c0-b939-4718-81f2-ca90353836cb&pd_rd_w=G3cqq&pd_rd_wg=6c3WR&pf_rd_p=1c11b7ff-9ffb-4ba6-8036-be1b0afa79bb&pf_rd_r=VFTD1C8EVY9SD8P3S359&refRID=VFTD1C8EVY9SD8P3S359&th=1

DC-DC 24V in to 12V out: https://www.amazon.com/Nextrox-Converter-Regulator-Transformer-Waterproof/dp/B00BWKXTUU/ref=pd_sbs_328_9?_encoding=UTF8&pd_rd_i=B00BWKXTUU&pd_rd_r=3a7d42c0-b939-4718-81f2-ca90353836cb&pd_rd_w=G3cqq&pd_rd_wg=6c3WR&pf_rd_p=1c11b7ff-9ffb-4ba6-8036-be1b0afa79bb&pf_rd_r=VFTD1C8EVY9SD8P3S359&psc=1&refRID=VFTD1C8EVY9SD8P3S359

DC-DC (Battery in OR 24V in to 20V out): https://www.amazon.com/Converter-DROK-Voltage-Regulator-Adjustable/dp/B075RQCW7G/ref=sr_1_13?keywords=20V+dc+dc&qid=1566858344&s=gateway&sr=8-13

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have fun :)