There is no universal, fixed formula for calculating the starting current of an LED lighting system, because the starting current of an LED lighting system is affected by many factors, including the rated power of the LED, the operating voltage, the circuit design (such as whether there is a rectifier circuit and a capacitor filter circuit), the resistance of the circuit board, etc.
However, I can give a detailed introduction on how to understand and estimate the starting current of an LED lighting system based on known information.
Characteristics of the starting current of an LED lighting system
1. Large instantaneous starting current: Since the LED driver circuit may contain a rectifier circuit and a capacitor filter circuit, when the LED lamp is instantly started, the filter circuit will have a very short charging process, and the current will be very large at this time. If the resistance of the circuit board is small, this charging current may be larger.
2. The relationship between the starting current and the rated current: For most LED lighting systems, the starting current is not equivalent to the rated current. The rated current is the current required by the LED during normal operation, while the starting current is the larger current experienced by the LED at the moment of starting. However, in some cases (such as simple circuit design, no large capacitor filter, etc.), the starting current may be close to the rated current.
How to estimate the starting current of an LED lighting system
1. Understand the basic parameters of the LED: First, you need to understand the rated power and operating voltage of the LED used. These parameters are the basis for calculating the current.
2. Consider the circuit design: Understand the circuit design of the LED lighting system, especially whether there is a rectifier circuit and a capacitor filter circuit. These circuits will affect the size of the starting current.
3. Estimate the starting current:
- If there is a large capacitor filter in the circuit design and the resistance of the circuit board is small, then the starting current may be very large, possibly reaching 1~2A or even higher.
- If the circuit design is relatively simple, there is no large capacitor filter or the resistance of the circuit board is large, then the starting current may be close to the rated current. The rated current can be calculated by the formula I=P/U, where I is the current, P is the power, and U is the voltage.
Notes
1. Actual measurement: Since the starting current is a transient value and is affected by many factors, the most accurate method is to obtain it through actual measurement.
Tools such as oscilloscopes or current clamps can be used to measure the current of the LED lighting system at the moment of startup.
2. Safety considerations: When measuring the starting current, you need to pay attention to safety.
Since the starting current may be large, you need to ensure that the measuring tool can withstand the corresponding current and avoid dangerous situations such as electric shock.
In summary, there is no universal formula for calculating the starting current of an LED lighting system.
Instead, it needs to be determined comprehensively based on the basic parameters of the LED, circuit design, and actual measurement conditions.