DOB Solution (Driver on Board):
Architecture: Integrates the AC-DC conversion, constant current control, and dimming circuitry directly onto the LED light source board (COB or PCB). High-voltage AC (e.g., 220V) is fed directly into the board, which houses an integrated high-voltage linear constant-current IC or a non-isolated step-down circuit.
Signal Transmission Limitation:
Dimming signals (e.g., PWM, resistor dividers) must be processed directly by the control IC on the board itself.
Adding an in-line DIP switch onto the power input cable equates to inserting mechanical contacts into the high-voltage AC path. Since the DOB's control circuitry sits after this power input, the switch would cut off power to the entire system (by breaking the high-voltage loop), rendering it inoperable.
Traditional Driver Solution (Independent Driver Power Supply):
Architecture: An independent power supply module outputs low-voltage DC (e.g., 12V/24V/48V) to the light source board. Dimming signals are transmitted separately via additional low-voltage control lines.
Signal Transmission Mechanism:
DIP switches are typically wired in series on the low-voltage dimming signal lines (e.g., D+/D- lines or dedicated dimming wires), not on the high-voltage main power path.
The switch toggles low-voltage DC signals (e.g., changing resistor values or switching PWM duty cycles). The driver IC identifies this signal and adjusts the output current or CCT accordingly, without impacting the main power supply loop.
Detailed Technical Limitations Analysis
1. Why DOB Solutions Don't Support In-line DIP Switching?
High-Voltage Loop Interruption:
Inserting a DIP switch physically severs the high-voltage AC loop → system power loss → the control circuitry remains inoperative.
Control Circuit Location:
All control functions (like CCT switching) are performed on the light source board and only become active after power is supplied. A switch placed at the input cuts power before the system energizes, preventing any signal response.
Safety Hazard:
Installing an accessible mechanical switch on a high-voltage line creates an electrical shock risk, violating safety regulations (e.g., UL/IEC 61347) which prohibit such additions.
2. Why Traditional Driver Solutions Support In-line DIP Switching?
Separated Low-Voltage Dimming Signal:
The DIP switch only needs integration into the low-voltage dimming lines (e.g., 0-10V, resistive dimming, PWM lines), leaving the main power lines undisturbed.
Signal Recognition Mechanism:
The driver's MCU determines the commanded level by detecting changes on the signal line – such as resistance value or PWM waveform changes.
Implementation Example:
E.g., Three-step CCT switching: DIP switch cycles through 3 resistor values → Driver detects distinct resistance values → Outputs corresponding current combinations (e.g., for 3000K / 4000K / 6000K).
Alternative Solution Suggestions
For physical DIP dimming on DOB systems, consider:
On-Board DIP Switch: Integrate a miniature SMD DIP switch directly on the light source board, connected to the control IC's GPIO pins. Drawback: Set during assembly, not user-adjustable.
Wireless Remote/APP Control: Add a Bluetooth/Wi-Fi module (e.g., Tuya solution) to the DOB board for switching via app or remote.
Wall Switch Control: Use specific AC power on/off sequences (e.g., On-Off-On) via wall switch with ICs like SM2082D.
Conclusion
The inseparable nature of high-voltage power delivery and control within DOB architecture makes mechanical in-line DIP switch dimming on the power cord infeasible. Traditional drivers overcome this via separate low-voltage control lines. For physical switching in DOB systems, integration must be on the board's low-voltage side or replaced by wireless alternatives.