What Is a TRS Connector?
The TRS terminal (TRS connector) is a connector commonly used to connect audio equipment to pass audio signals. The word is an acronym for its three components: Tip, Ring, and Sleeve. Because this connector is generally used to plug in headphones and microphones, it is also called Phone Jack. Although they are collectively referred to as TRS, they can also be called TS (no ring, that is, a tip and a sleeve provide one contact point) and TRS (one ring, three contact points) according to the number of rings (R) of a specific plug / socket , TRRS (two rings, four contact points), and so on.
- The TRS terminal is a connector used to implement the transmission and control of audio signals and the connection between electronic devices [1]
- Audio equipment is still common and was used in manual telephone exchanges around the 1970s
- Computer sound card input and output
- Headphones and audio output (AUX) connections for 3C products such as Walkman and mobile phones. The iPhone 7 launched by Apple in 2016 no longer has this terminal built-in, and is replaced with a Lightning connector; some Android smartphones are gradually replacing this terminal with a USB-C connector.
- iPod shuffle and some micro devices also use this terminal as an interface for power input.
- TS, TRS and TRRS are available in mono, dual and "dual + microphone" respectively. TRRS is commonly used in mobile phones. However, there is no unified standard on which signal is transmitted at each of the four TRRS contact points, which causes some headphones to only sound unilaterally when plugged into the jack. Some slightly advanced headphones will have a changeover switch to solve this problem. There are also TRRS sockets for audio and video signal output, which are commonly used in digital cameras, digital camcorders, portable DVD players and other equipment, with a 3.5mm (male) to RCA (female) adapter cable.
- Earphone connections for early handheld walkmans or mobile phones are now rare in audio effects or music playback devices, and are mostly used to power small devices or input / output power.
- Relay (relay) is an electrical control device, which is an electrical device that causes the controlled quantity to undergo a predetermined step change in the electrical output circuit when the change in the input quantity (excitation quantity) reaches the specified requirements. It has an interactive relationship between the control system (also known as the input loop) and the controlled system (also known as the output loop). Usually used in automated control circuits, it is actually an "automatic switch" that uses small currents to control high current operations. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit. The relay has the following functions:
- Enlarge the control range: For example, when the control signal of the multi-contact relay reaches a certain value, the multi-circuit can be switched, disconnected and connected at the same time according to different forms of the contact group.
- Amplification: For example, sensitive relays, intermediate relays, etc., can control very large power circuits with a very small amount of control.
- Comprehensive signal: For example, when multiple control signals are input to a multi-winding relay in a prescribed form, they are compared and integrated to achieve a predetermined control effect.
- Automatic, remote control, and monitoring: For example, the relays on the automatic device, together with other electrical appliances, can form a program control circuit to achieve automatic operation.