MOSFET LR7843 Control Module (High-Current Solid-State Relay Replacement)
Take command of extreme current direct-current loads and optimize your automation switching networks with the industrial-grade MOSFET LR7843 Control Module. Engineered specifically as a high-speed, solid-state replacement for traditional mechanical relays, this module utilizes the ultra-low internal resistance LR7843 metal-oxide-semiconductor field-effect transistor combined with an optical isolation network to deliver wear-free, instantaneous power management.
Unlike standard electromagnetic relays that suffer from mechanical contact wear, audible clicking noise, and destructive back-electromotive force spikes, this solid-state board runs entirely electronically. It handles massive power throughput while keeping heat generation remarkably low. It serves as the definitive choice for high-frequency Pulse Width Modulation motor drivers, heavy-duty heating elements, automotive electronic switches, and industrial automation control panels.
Key Features
Full Optical Logic Isolation: Built with an onboard high-speed optocoupler chip that completely separates the low-voltage control input side from the high-power load grid, ensuring that inductive voltage spikes never reach your master microcontroller.
Ultra-Low Internal Resistance Chipset: Features the elite LR7843 switching transistor package, which exhibits incredibly low resistance during its active ON state to maximize current throughput and minimize thermal accumulation.
Massive Current and Voltage Matrix: Supports a wide output load voltage range from 6V up to 28V DC, comfortably managing massive continuous running currents up to 30 Amps (and handling extreme peak bursts up to 161 Amps under strict duty cycles).
High-Frequency PWM Control Loop: Responds instantly to rapid digital Pulse Width Modulation lines, making it perfect for precision duty-cycle applications such as flicker-free LED dimming and ultra-smooth DC motor velocity profiling.
Low-Voltage Microcontroller Trigger: Operates flawlessly using digital control levels from 3.3V to 12V DC, making it plug-and-play compatible with modern development platforms like Arduino, ESP32, STM32, and Raspberry Pi.
Heavy-Duty Screw Terminals: Features robust, industrial-grade terminal blocks on the load input and output paths to ensure rock-solid, vibration-resistant wiring hookups under harsh industrial vibrations.
Technical Specifications
Feature | Specification |
Core Switching Transistor | LR7843 High-Power MOSFET Package |
Isolation Chipset | High-Speed Onboard Optocoupler |
Output Load Voltage Range | 6V to 28V DC |
Trigger Logic Input Voltage | 3.3V to 12V DC (Supports standard microcontroller outputs) |
Continuous Operating Current | 30 Amps (With active airflow or auxiliary heatsink blocks) |
Maximum Rated Peak Current | Up to 161 Amps (Short pulse durations only) |
Control Signal Frequency Support | Fully compatible with high-speed digital switching and PWM lines |
Board Dimensions | 34 mm x 17 mm x 12 mm |
Hardware Wiring & Interface Configuration
The module features a highly organized layout that ensures straightforward, error-free system wiring:
1. Control Input Side (3-Pin Header)
VCC: Connects to the logic power supply rail of your microcontroller setup (3.3V to 12V).
GND: Connects to the common ground reference of your control logic rail.
IN (Signal Trigger): Connects directly to the digital I/O or PWM output pin of your microcontroller to drive the internal optocoupler.
2. High-Power Load Side (Screw Terminals)
DC+: Connects to the positive power rail of your external high-power DC battery or bench supply (6V to 28V).
DC-: Negative return path of your external high-power supply.
OUT+: Connects directly to the positive power terminal of your target DC motor, solenoid valve, or LED array.
OUT-: Connects directly to the negative return terminal of your target load device.
Common Applications
Solid-State Relay Retrofitting: Replace failure-prone mechanical relays in automated distribution systems to guarantee continuous operation without downtime.
High-Power DC Motor Velocity Governors: Adjust the speed of heavy cooling fans, autonomous rover drive setups, and rugged conveyor lines via microcontroller PWM duty cycles.
Heavy-Duty LED Dimming arrays: Manage massive industrial illumination banks, agricultural grow lights, or stadium indicator grids smoothly without flickering.
High-Wattage Heating Elements: Safely manage the high current demands of 3D printer heated beds, industrial warming coils, and localized incubator grids using precise PID temperature-matching loops.
🛠️ Pro-Engineering Operating Tip: Because this module features full optocoupler isolation, it provides complete electrical separation between the control circuit and the high-voltage load circuit. For applications requiring complete isolation against heavy inductive back-electromotive force, make sure that the ground line of your microcontroller loop is kept completely independent from the negative supply terminal of your high-power load battery.
Package Includes:
1 x MOSFET LR7843 Control Module (Optocoupler-Isolated Solid-State Relay)