12V (10-24V) To 9V 1.7A DC-DC Waterproof Step-Down Converter Power Supply Module F23J9V1.7A4S
12V (10-24V) To 9V 1.7A DC-DC Waterproof Step-Down Converter Power Supply Module F23J9V1.7A4S
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📋 Overview
This miniature DC-DC step-down converter takes a 10–24V DC input (nominally 12V) and delivers a clean, regulated 9V DC output at up to 1.7A (15W maximum). It's a waterproof, straightforward way to power 9V electronics — sensors, alarm panels, small instrumentation, and more — directly from a 12V battery, vehicle system, or wall adapter.
Built as a non-isolated buck (step-down) converter, it operates at over 96% efficiency, so very little power is wasted as heat even under full load. The epoxy-sealed housing makes it safe for outdoor, automotive, or otherwise exposed installations.
⭐ Key Features
- Regulated 9V output — Clean, stable power for 9V devices, sensors, and instrumentation
- Wide input range — Accepts 10–24V DC, ideal for 12V nominal systems with voltage sag or charging spikes
- Epoxy-sealed, waterproof housing — Safe for outdoor, automotive, and marine use
- High efficiency — Greater than 96% efficient, minimal heat generation
- Built-in protection — Overload, over-current, over-voltage, and low-voltage protection with automatic recovery
- Compact and lightweight — Easy to tuck into enclosures, dashboards, or inline wiring runs
📊 Specifications
| Specification | Value |
|---|---|
| Envistia Model Number | F23J9V1.7A4S |
| Input Voltage Range | 10–24V DC |
| Nominal Input | 12V DC |
| Output Voltage | 9V |
| Max Output Current | 1.7A |
| Max Output Power | 15W |
| Approx. Max Input Current (at full load, 12V in) | ~0.75A |
| Quiescent Current (no load) | <10mA |
| Efficiency | >96% |
| Operating Temperature | -40°C to +70°C |
| Size (L × W × H) | Approx. 38 × 27 × 23 mm (1.50 × 1.06 × 0.91 inches) L × W × H (52 mm / 2.05 inches overall length including mounting tabs) |
| Weight | Approx. 30g |
| Input & Output Wire Length | Approx. 12cm (4.7 inches) per lead |
| Input & Output Wire Size | 0.5mm² cross-sectional area, equivalent to ~20 AWG |
| Case Color | White |
| Housing | Epoxy-sealed, waterproof |
📝 Note: Unlike the 3.3V, 5V, and 6V models in this series, the 9V model requires a minimum input of 10V DC rather than 8V DC. Make sure your 12V source doesn't sag below 10V under load.
🔌 Wiring & Connections
Two pairs of wires — no pins or connectors needed. Simply splice, solder, or crimp into your circuit.
| Wire Color | Function |
|---|---|
| Red (input side) | Input +V — connect to your 12V positive supply |
| Black (input side) | Input Ground — connect to your 12V negative/ground |
| Red (output side) | Output +V — connect to your load's positive terminal |
| Yellow (output side) | Output Ground — connect to your load's negative/ground terminal |
Wire gauge: all leads are 0.5mm² cross-sectional area (20 AWG).
⚠️ Important: Double-check polarity before powering up. Reversing the input wires can damage the converter, and reversing the output wires can damage your connected device.
⚠️ Important Notes
Your 12V input power source must be able to supply at least as much power as your load will draw from the output, divided by the converter's efficiency (~96%). If the input source can't keep up, the output voltage will fold back (sag) rather than deliver the full 9V. See the full User Guide linked below for wiring diagrams and a detailed power-budget walkthrough.
This is a constant-voltage (CV) converter, not a constant-current (CC) converter. It regulates to 9V and supplies whatever current your load draws, up to 1.7A maximum — it will not force more current into your device than it needs.
📦 What's in the Box
- 1× 12V to 9V 1.7A Mini DC-DC Step-Down Converter (F23J9V1.7A4S)
🎯 Applications
- 9V battery replacement — Power 9V-battery-operated devices continuously from a 12V source instead of swapping batteries
- Sensor and remote monitoring power — Power 9V sensors, dataloggers, or instrumentation from a 12V battery or solar setup
- Alarm and security panel power — Provide clean, regulated 9V power to legacy alarm or security equipment
- Audio and effects equipment — Power 9V guitar pedals or small audio devices from a 12V vehicle or bench supply
📄 Documentation & Resources
- User Guide — Wiring, specifications, Mechanical & STEP Files, power-budget calculations & troubleshooting
- All Buck Step-Down DC/DC Converter User Guides
🛒 Other Models in the F23J Series
- 12V to 3.3V 3A DC-DC Converter (F23J3V3A4S)
- 12V to 5V 3A DC-DC Converter (F23J5V3A4S)
- 12V to 6V 2.5A DC-DC Converter (F23J6V2.5A4S)
Sold and supported by Envistia Mall. Ships from the USA. For wiring diagrams, sample code, and troubleshooting, see the User Guide tab on this product page. The manufacturer and Envistia LLC (dba Envistia Mall) are not responsible for any damages or losses resulting from the use of this product. Always follow proper electrical safety practices when working with electronic components. Specifications are based on manufacturer data and are subject to change without notice.
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- 5 stars: 18 (90%)
- 4 stars: 1 (5%)
- 3 stars: 0 (0%)
- 2 stars: 1 (5%)
- 1 star: 0 (0%)
Good service with great prices
Worked as advertised
I needed this item to power a 9V sensor on a remote tank, powered by a solar cell and battery storage. Works great - reliable so far, and nice clean and steady 9V power to my sensor electronics for 24hour monitoring and alerts. Good product for my needs.
I needed 1.5amp so 1.7 would have been fine but this 3amp is too much power then I need...I wish there was a way to speak to the seller to get the correct ones but there isn't a way
Thank you for your feedback. We apologize for any inconvenience this may have caused. We want to clarify that this is a constant voltage (CV) converter, not a constant current (CC) converter. It regulates the voltage to 9V and will supply whatever current your load will draw, up to its maximum. If you need to limit the current, we recommend using a converter with a current limit control. If you have any further concerns, please feel free to reach out to us and we will be happy to assist you.
Works as advertised
Works great and does what it says.
I have a 9vdc fan I wanted to connect to my 12vdc solar unit. Works great
Used for brake light in truck when towing and when auxiliary braking is attached 9v transmitter is supplied by this - priced right and recommend to friends and family
I used this step-down to hardwire in my Weather Alert radio to our RV. Works as expected.
Dropped it from a 12v to a 9volt like they said
This step-down module is being used to power a wifi-connected IP camera. This device is allowing me to take 12v directly from a battery/solar panel/charge controller and feed it to the camera. This bypasses the need for a 12vDC->120vAC->9vDC transformation along with the inefficiencies that would come at each conversion (or a 12v ->5v USB -> 9v conversion).Well worth the investment for a nearly seamless closed DC power system.
I am using this with a W1209 thermostat to ensure that fluctuating power is held steady. It appears to be working just fine.
I used this to slow down my Lionel billboard that was way too loud and rough. It worked. I just wish I had bought one that put out less voltage.
Just what I needed and was as described.
It works
Worked great
I needed 9 volts from a 12 volt environment. I installed a 9 volt alarm in my car.
Bench checked at 13.6 VDC, output was 9v on a 1 Amp load. 73 / KD4WDG
Looks like what I ordered.
It works perfectly to provide 9 volts to trigger a smoke alarm network.