LED lighting circuit design from the market demand (2)

AC LED has the advantage of low cost in concept, but in fact, there are many problems to be overcome, such as safety, efficiency and heat dissipation. Therefore, from the perspective of overall system design, AC LED still has a long period of time. The way to go.

Because LED has the characteristics of energy saving and non-polluting, it is quite popular among many electronics and system manufacturers in terms of the choice of light source. LED itself has luminous characteristics, and the industry will of course promote the rapid take-off of LED lighting.

In the article "From the perspective of market demand, LED lighting circuit design (on)", it is mainly the views and development trends of DC LED circuit design by major semiconductor manufacturers. This time, it is through the semiconductor industry. Talk about the future development of AC LED from the perspective of circuit design.

Wu Yushan, Business Integration Manager of Power Integrations, said that the reason why the AC LED concept will be discussed by the industry is that the DC LED technology patent is almost controlled by foreign companies. In order to develop smoothly in the LED lighting field, companies from all over the world hope to use AC. LEDs to avoid foreign patent layout, and further can be technically separated from foreign companies. Therefore, some companies in Taiwan have begun to focus on the development of AC LEDs. In 2008, the "AC LED Application R&D Alliance" was established. Through cooperation with the Taiwan Industrial Technology Research Institute, it is hoped to further accelerate the popularization of AC LEDs. In 2009, the "AC LED component optical and electrical measurement method" and "AC LED module optical and electrical measurement method" were also completed. In 2010, five draft AC LED related standards were also completed, namely “AC LED luminaire optical and electrical measurement”, “AC LED safety recommendation specification”, “LED indoor lighting standard” and “LED outdoor lighting standard”. And "LED lighting optical and electrical measurement". But in fact, there are still many challenges to overcome in current AC LEDs.

Wu Yushan pointed out that the difference between AC and DC is that AC can reduce the circuit or even the overall system cost without rectification and isolation. However, if you want to pass the safety threshold, if you want to use non-isolated AC LED, System operators must use institutional design to overcome security norms. However, in terms of circuit design, in order to stabilize the current or voltage supply, adding a rectifier can solve this problem, but the operating frequency will be raised to 100 Hz or 120 Hz. However, it is necessary to pay attention to the fact that the human body may have a negative impact on the human body under the long-term illumination of the operating frequency of 120 Hz. In addition, from the perspective of the overall system of AC LED, PFC (power factor correction), life and LED arrangement must also be considered. The merits of circuit design is only one of the challenges of AC LED.

Type C Usb Hub

Type-C interface has strong expansion ability, can transmit video and video signals, expand to a variety of audio and video output interface, such as HDMI, VGA, DVI interface, and even achieve 4K resolution of the extended transmission. The Type-c interface provides bidirectional power supply, which can charge the device itself or power external devices.USB HUBS has better data transmission capability and higher charging power. USBType-C went into mass production in August 2014, using the 3.1 standard. Compared with the interface of USB2.0 used in early smartphones, the transmission speed is improved a lot, and the maximum data transmission speed can reach 10Gbit/ s. And type-c supports USB-PD power supply standard, the maximum power supply can be up to 100 watts. Different from the traditional USBType-A and Type-B interfaces, the new Type-C interface is slimmed down in size to 8.3*2.5mm, which is more suitable for use in increasingly miniaturized electronic devices.

Supports positive and negative insertion. 100% of the players who use USB interface have encountered the embarrassment of "the positive plug is wrong, the negative plug is wrong, and the positive plug is right". Because USB-C IS POSITIVE AND NEGATIVE CAN be inserted, professional point is to say that the interface does not have directionality, with much more convenient. type-c charging port, support PD fast charging protocol, can be charged while using the computer, not afraid of running out of power. HDMI interface, I like HDMI to support audio and video transmission, high resolution support 4K/2K. Interface is common, LCD TV, monitor, projector are generally also some (like to connect to TV, audio and video synchronous transmission).vga interface, this is a very common interface, most of the projector, monitor have this interface, can be connected to vga line use, support 1080P resolution. Gigabit network port, although now almost everywhere there is a wireless network, but sometimes it is not enough for you, such as playing games, the network speed is slow, delay. And then he dropped the line right in the middle of his victory. So if you have a network cable and you can connect directly to the Internet, it's great to support gigabit networks.

Type C Usb Hub,Fast Charging Usb Hub,Hub Type C To Usb,Usb 3.1 Type C Hub

Henan Yijiao Trading Co., Ltd , https://www.yijiaousb.com