Nowadays, IP telephony is a well-known term. The so-called IP telephony is relative to traditional telephony. Its biggest advantage is to make full use of the existing telephone line and transmit voice over the ubiquitous Internet. This greatly reduces the cost of calls and is therefore highly appreciated and respected by users.
The IP telephone is an independent communication device with the IP network protocol as the main communication protocol and the network port (or WIFI) as the main interface. It has the dialing and calling functions. Currently, the communication protocols commonly used by IP phones are SIP, IMS, MGCP, SCCP. Etc., where SIP is more commonly used. Also known as VoIP.
IP phones usually have a few more buttons than regular phones, for richer call functions, such as menu buttons, transfer buttons (instead of flashing hooks), conference buttons, pause buttons, mute buttons, headset buttons, volume adjustments. Keys, navigation keys, etc.
What is the difference between an IP telephone and a general telephone?
Usually, when we make a normal call, whether it is a local call or a long-distance call, both parties must occupy a temporary special line, and the line must not be occupied by others during the call. However, in fact, this call line can not be used 100%, and most of it is wasted.
The biggest difference between an IP phone and a regular phone is that it makes full use of the Internet. Based on the TCP/IP protocol, the voice signal of the caller is sampled and digitized by a special device or software, and compressed and packaged at the same time. The voice information is converted into small data packets, which are freely searched for the network free space through the network, and transmit the voice information to the other party. After receiving the voice packet, the other party's special equipment or software decompresses and restores the analog signal to the analog signal. phone. In this way, although it seems that the process is very troublesome, it is not necessary to establish a dedicated line during the call, but only use the network to see the stitches, which greatly saves the cost of the call, which is why the money is saved by dialing the IP phone.
I think everyone should understand that IP telephony is actually a kind of telephony application realized by the communication network through TCP/IP protocol, and this application mainly includes PC to PC, PC to Phone and Phone to Phone.
Let's take a look at the schematic of an IP cordless phone PCB circuit:
IP cordless phone schematic
The above is the IP cordless phone PCB and schematic.
Floating Ball Liquid Level Sensor
The floating ball liquid level transmitter is composed of magnetic floating ball, measuring conduit, signal unit, electronic unit, junction box and mounting parts. Generally, the specific gravity of the magnetic floating ball is less than 0.5, which can float above the liquid level and move up and down along the measuring conduit. The conduit is equipped with measuring elements, which can convert the measured liquid level signal into a resistance signal proportional to the change of liquid level under the action of external magnetism, And convert the electronic unit into 4 ~ 20mA or other standard signal output.
The liquid level sensor is a modular circuit, which has the advantages of acid resistance, moisture resistance, shock resistance and corrosion resistance. The circuit contains a constant current feedback circuit and an internal protection circuit, which can make the maximum output current no more than 28ma, so it can reliably protect the power supply and prevent the secondary instrument from being damaged.
Floating Ball Liquid Level Sensor,Liquid Level Measuring Sensor,Float Type Liquid Level Sensor,Liquid Level Measurement Sensor
Taizhou Jiabo Instrument Technology Co., Ltd. , https://www.taizhoujbcbyq.com