Cob led has three pins, one is connected to the positive electrode, the other is connected to the negative electrode, and the other is connected to what. After measurement, it is not connected to the aluminum substrate. Pins marked other than+and-usually do not need to be connected. All valid pins should be marked normally, which is probably a general aluminum substrate, and reserved pins for manufacturing different types of products. Use a multimeter to measure whether+and-are connected to these pins respectively.

The driving voltage is 9- 1 1V, the current is 150mA, and the power is 1.5W, which is only half of what you said.

To achieve 3W power, either double the voltage; Either double the current; Either the voltage and current parameters are correct, but there are two parallel branches inside the COB chip (if the voltage parameters are good, try to power up the unlabeled pins with DC power supply with appropriate voltage and surplus current, and if the observation results are not bright, this possibility can be ruled out).

COB has no essential difference from other LEDs, except that N LED chips are directly packaged on specific circuit boards such as aluminum substrates, with compact structure and high reliability.

The excess current mentioned above means that the power supply can provide more than 300mA of current. If the COB is properly connected between the positive and negative pins, it will not light up unless the COB is damaged. It is really necessary to consider the cause of insufficient supply voltage. Whether to apply voltage directly, consider clearly, at your own risk. There is also a safe trial method. Find a constant current source with adaptive output voltage for led candle lamp (provided online). Output parameters are 150mA, 1~ 10 (refers to the number of discrete LEDs that can be driven in series, and the voltage is adaptive within this range). After correct wiring, observe the lighting:

If the voltage measured at both ends of COB under normal illumination is normal working voltage, the current is indeed150mA; ;

If the luminous brightness is obviously insufficient-the voltage has the above meaning, but the normal working current of COB is definitely much greater than150mA; ;

If it still doesn't light up, you can basically judge that COB is broken.