Ozone and ultraviolet disinfection is the most widely used low‑temperature disinfection method for household and commercial disinfection cabinets. The control board is responsible for the precise drive, safety interlock, timing management and fault protection of UV lamps and ozone generators. The circuit must adapt to high humidity, ozone corrosion and electromagnetic interference, and realize stable, efficient and safe automatic disinfection. This article focuses on the circuit composition, control logic, drive technology and safety protection of ozone and ultraviolet disinfection modules.

1. Overview of Ozone + Ultraviolet Disinfection System

Ultraviolet (UV) disinfection uses 253.7nm UV‑C to destroy bacterial DNA and RNA. Ozone disinfection uses strong oxidization to kill viruses and bacteria in dead corners. The two work together to achieve full‑range, no dead‑angle disinfection. The control board needs to complete:

• UV lamp on/off control and fault detection

• Ozone generator drive and output stabilization

• Synchronous or sequential control of UV and ozone

• Door interlock, overload protection and timing control

2. Ultraviolet Disinfection Lamp Drive Circuit

UV disinfection lamps are mostly low‑pressure mercury lamps, which require high‑voltage ignition and stable current output. The drive circuit includes:

• Ballast / current limiting resistor: stabilizes lamp current and prevents burnout

• Relay / thyristor switch: controlled by MCU to turn UV lamp on/off

• Anti-interference filter: absorbs surge and reduces electromagnetic interference

• Overcurrent protection: fuse or current detection to avoid short circuit damage

The circuit working principle: MCU outputs control signal → optocoupler isolation → relay pull‑in → UV lamp lights up for disinfection. When disinfection ends or door opens, the relay is disconnected immediately.

3. Ozone Generator Drive Circuit and Control Technology

Ozone generators for disinfection cabinets usually use high‑voltage discharge type or ceramic ozone plates. The control board provides high‑frequency and high‑voltage drive.

Core circuit structure:

• Oscillation circuit: generates high‑frequency AC signal

• Boost transformer: outputs 2000–3500V high voltage to produce ozone

• Drive triode / MOS tube: controlled by MCU PWM or I/O signal

• Current limiting and overheat protection: prevents ozone plate breakdown

Control logic: MCU starts ozone output synchronously with UV lamp; adjusts ozone concentration by operating time; stops output when door opens or fault occurs.

4. UV + Ozone Combined Control Logic

The control board supports three operating modes to meet different disinfection requirements:

• Simultaneous mode: UV and ozone work at the same time for fast disinfection

• Sequential mode: UV first, then ozone, to improve penetration and sterilization effect

• Cycle mode: intermittent operation to extend life and reduce ozone residue

The MCU automatically manages startup sequence, running time and shutdown delay according to the program.

5. Door Interlock Protection Circuit (Key Safety Technology)

To prevent UV radiation and ozone leakage, the control board is equipped with a mandatory door interlock system:

• Cabinet door switch detects open/close state in real time

• Once door opens during operation, MCU immediately cuts off UV and ozone

• Hardware and software dual protection to ensure personal safety

• Only when door is closed can disinfection be started

6. Timing Control and Automatic Disinfection Process

The control board uses high‑precision timer to realize full automatic disinfection:

• Startup: door closed detection → system self‑check → load start

• Operation: UV + ozone work synchronously, countdown in real time

• Midway door open: pause immediately, resume after closing door

• End of timing: cut off all loads, buzzer prompt

• Automatic ventilation delay: reduce ozone residue

7. Fault Detection and Protection Circuit

The control board has complete fault monitoring to ensure stable operation:

• UV lamp open circuit / short circuit fault detection

• Ozone generator overload / overheat protection

• Overcurrent, overvoltage and surge protection

• Sensor abnormality and door switch fault alarm

When a fault is detected, the system locks the load and displays the fault code.

8. Anti‑interference and Environmental Adaptation Design

Disinfection cabinets work in high humidity and ozone environments, so the circuit adopts:

• Optocoupler isolation between strong and weak electricity

• Three‑proof paint (moisture‑proof, ozone‑proof, corrosion‑proof)

• Wide‑range voltage regulation to adapt to grid fluctuations

• Filtering and shielding to reduce EMI interference

9. Summary

Ozone and ultraviolet disinfection control technology is the core of low‑temperature disinfection cabinets. The control board realizes stable drive of UV lamps and ozone generators through professional drive circuits, combined with door interlock, timing control, fault protection and anti‑interference design. It ensures thorough disinfection, safe use and long service life, and is the key technology for modern disinfection cabinets.