A purely linear device, connected in series in the LED circuit, relies on its own voltage drop to dissipate excess voltage and keep the circuit current constant.

1. Extremely simple circuit, no inductor required, extremely low EMI interference;

2. Suitable for low-current, low-power applications: small indicator lights, automotive ambient lights, small digital indicator lights;

3. Weakness: The larger the voltage difference, the more severe the heat generation, making it unsuitable for high-power, high-low voltage difference applications;

4. Some models support linear dimming, extremely low cost.