RayRailSwSense
Smart high-side power switch board for amplifier drain rails (12–60 VDC) with current-sense output, blade fuse, and TVS surge. Offered in two build options by swapping U1: 25 A or 50 A. Designed to pair with RaySspaController yet open for easy integration with any MCU.
Overview
RayRailSwSense switches and monitors your amplifier’s DC rail using a smart high-side switch IC (U1) with built-in protection and a precision IS current-sense pin. The sense line is scaled to 0–3.3 V for direct connection to an ADC (e.g., ADS1115) on the controller. Logic control uses 3.3 V inputs (IN/DEN), and the board includes a field-replaceable blade fuse, input TVS, bulk/RC filtering, and a ferrite bead on the logic 3.3 V rail.
Two SKU options are supported by swapping U1: a 25 A version and a 50 A version. The pin header (J3) exposes Out+, 0–3.3 V Out, logic IN, optional VIN-sense, IS/Out-sense, and GND for easy adoption by third-party controllers, PLCs, or test rigs.
At a Glance
- • Input: 12–60 VDC
- • Build options: 25 A or 50 A (swap U1)
- • 0–3.3 V current-sense output for ADC
- • Blade fuse holder on board
- • TVS surge diode + bulk cap
- • 3.3 V logic (IN / DEN)
Key Features
Smart High-Side Switching
- U1 smart switch with integrated protections
- Enable/disable via IN and DEN pins
- Short-circuit, over-current, and thermal handling (per U1)
- Reverse-battery / transient resilience with TVS + fuse
Current Sense for Telemetry
- IS pin provides proportional sense current
- Scaled to 0–3.3 V for MCU ADC (divider + RC)
- Supports EMA smoothing and alarms in the controller
- Optional VIN-sense line for rail monitoring
Power Integrity & Safety
- Blade fuse holder (F1) for field serviceability
- SMCJ TVS at input for surge suppression
- Bulk decoupling and RC filtering on sense/logic
- Ferrite bead on 3.3 V logic feed (noise control)
Open Integration
- Controller-agnostic: Teensy, ESP32, Arduino, PLC
- J3 header exposes Out+, Out(0–3.3 V), IN, VIN-sense, IS/Out-sense, GND
- 3.3 V logic compatible (through existing driver network)
- Clear silkscreen labels + wiring examples
Hardware Overview
Input connector J1 feeds the blade fuse F1 and TVS diode D1.
The protected rail enters U1 (smart high-side switch). Output connector J2
provides switched +Vout. The IS pin is routed through a small resistor (~200 Ω)
and RC to generate a stable 0–3.3 V sense at J3-2/J3-5. Logic control uses 3.3 V
IN and DEN lines. A ferrite bead filters the 3.3 V logic input.
J3 Control & Sense Header (typical)
- 1: Out+ (rail monitor)
- 2: Out (0–3.3 V) for ADC
- 3: IN (3.3 V logic)
- 4: VIN-Sense (optional)
- 5: Out-Sense / IS (to ADC)
- 6: GND
Build Options
- 25 A build: mid-power rail switching
- 50 A build: higher-power modules
- Same PCB & pinout; U1 device differs
- Fuse value set per build/current profile
Quick Specs
- Input: 12–60 VDC
- Current: 25 A or 50 A (per U1 build)
- Sense Output: 0–3.3 V (to MCU ADC)
- Logic: 3.3 V IN / DEN
- Protection: Blade fuse ATO/ATC + TVS + U1 internal protections
- Integration: Controller-agnostic (RaySspaController optional)
- Board Dimensions: L = 60 mm, W = 40 mm
Available Variants
| Model | Switch Device (U1) | Max Continuous Current | Notes |
|---|---|---|---|
| RayRailSwSense-25A | BTH500301LUAAUMA1 | 25 A | Power amplifiers & test benches |
| RayRailSwSense-50A | BTH500151LUAAUMA1 | 50 A | High-power rails up to 60 V DC |
Purchase Options (Coming Soon)
Online ordering for RayRailSwSense is not enabled yet. The options below show the planned variants and how they will appear once the RF StateSide store is live. In the meantime, feel free to contact me directly if you are interested in early hardware.
RayRailSwSense-25A
Assembled & tested
Price: $TBD USD
- 12–60 VDC, up to 25 A
- Fully assembled module
- Ideal for single-module rails or medium power
RayRailSwSense-25A Kit
Unassembled kit
Price: $TBD USD
- 12–60 VDC, up to 25 A
- PCB + BOM / parts kit
- Great for homebrew and lab builds
RayRailSwSense-50A
Assembled & tested
Price: $TBD USD
- 12–60 VDC, up to 50 A
- High-current rail switching
- Ready for multi-module HF amplifiers
RayRailSwSense-50A Kit
Unassembled kit
Price: $TBD USD
- 12–60 VDC, up to 50 A
- PCB + parts kit (including power devices)
- For experienced DIY and lab integration
Until the online store is live, you can email Ray (KB1SO) to discuss availability, pricing, or early-access hardware.
Downloads
Coming soon: pinout diagram, wiring examples (Teensy/ESP32), sense-scaling notes for 25 A/50 A builds, and recommended fuse/TVS selections per rail voltage.
Gallery
RayRailSwSense PCB Board
RayRailSwSense Assembled Board
This photo has been AI-enhanced to improve lighting and clarity; the physical product may differ slightly.
Interested in RayRailSwSense?
RayRailSwSense provides reliable switching and current sensing for amplifier modules and automation workflows. If you’d like to integrate the module into your controller or station build, reach out for details or design guidance.