In machine vision system, light source is one of the important factors affecting image quality and detection effect. In order to ensure the stability and controllability of the light source, we need to use the light source controller to power and adjust the light source. So, how to choose the right light controller? This article will be introduced from the following aspects:

Basic functions of light source controller
Classification and characteristics of light source controller
Light source controller selection points
Basic functions of light source controller
The most important function of the light source controller is to supply power to the light source, control the brightness of the light source and the illumination state (on or off). In addition, there are several common features:

External trigger: Input of external signals (such as camera trigger signals) into the controller can cause the light source to be ststrobe illuminated, thus greatly extending the life of the light source and improving image contrast.
Brightness adjustment: Adjust the brightness of light source manually or by computer to adapt to different environments and targets.
Multi-channel output: you can control multiple light sources at the same time to achieve synchronous or asynchronous lighting.
Data protection: You can save the set parameters to avoid having to reset each time you start up.
Overcurrent protection: prevents excessive current caused by short circuit or other reasons from damaging the device.
Classification and characteristics of light source controller
According to different control and adjustment methods, we can divide the light source controller into the following types:

Analog controller: The use of analog signal to control the light source, brightness stepless adjustment, simple operation, but the accuracy is low, easy to be interfered.
Digital controller: The use of digital signal to control the light source, brightness level adjustment, complex operation, but high precision, good stability.
Linear controller: The use of linear circuit to control the light source, the output voltage or current is proportional to the input signal, the response speed is fast, but the efficiency is low, the heat is large.
PWM (pulse width modulation) controller: use PWM signal to control the light source, the output voltage or current is proportional to the duty ratio of the input signal, the response speed is fast, the efficiency is high, the heat is small.
According to different output power and channel number, we can divide light source controller into the following types:

Low power controller: the output power is less than 10W, usually used to control point light source, line light source and other small light source, low price, small volume.
Medium power controller: output power between 10W-100W, usually used to control ring light source, parallel light source and other medium light source, moderate price, moderate volume.
High power controller: The output power is more than 100W, usually used to control large area backlight, projection light source and other large light source, high price, large volume.
Light source controller selection points
When choosing the light source controller, we need to consider the following aspects:

Types and parameters of light sources: Different types of light sources need to match different types of controllers. For example, LED light sources need constant-current or constant-voltage controllers and halogen lamps need constant-voltage controllers. At the same time, but also pay attention to the voltage, current, power and other parameters of the light source, choose the appropriate output range and power controller.
Lighting mode and effect: Select a controller with or without an external trigger function based on the lighting mode. For example, a controller without a trigger function can be used for continuous lighting and a controller with a trigger function can be used for ststrobe lighting. At the same time, we should consider the requirements of lighting effect and choose the appropriate brightness adjustment mode and precision controller. For example, digital controller is needed for high-precision detection, and analog controller can be used for low-precision detection.
Control mode and convenience: according to the different control mode, select the controller with or without computer or manual control function, such as the need for remote or automatic control occasions can use computer control function of the controller, the need for field or manual adjustment occasions can use manual control function of the controller. At the same time, the convenience and usability of the controller should be considered, and the controller with or without data protection, overcurrent protection, multi-channel output and other additional functions should be selected.
Price and cost performance: According to the different budget and demand, choose the appropriate price and cost performance of the controller, generally speaking, the more functions, better performance, more well-known brand of the controller, the higher the price, but also may have higher stability and quality assurance. On the contrary, there may be a lower price and cost performance.
In short, when choosing the light source controller, we need to consider various factors comprehensively and make the best choice according to our actual situation and needs.