Most of high precision constant current sources use integrated operational amplifier. The principle is to make the voltages added to the two input ports of the comparison amplifier are equal by using negative influence, resulting in constant current output there are two factors that affect the stability of the output constant from the constant current sources: one is the inner factor of the constant current source, like voltage reference, sampling resistor, amplifier gain, zero drift, and noise ...(more)
This article continues to introduce TEC loss mechanism. (2) Heat conduction loss In cooling process, heat conduction mainly plays a role of heat change. The pathway of heat conduction is that the cold side absorbs the heat of heat load, which can be transferred to heat sink, so the cold side thermoregulation can be realized. The cooling capacity can directly affect TEC cooling efficiency. Whats more, the size and the cooling method of heat sink are also important factors to affect the cooling ef...(more)
Figure 1 is the schematic diagram of thermoelectric cooler (TEC). TEC is made up of N-type semiconductor, P-type semiconductor, cold pate, hot plate and wires. Figure 1. Schematic diagram of TEC In working process, TEC continuously absorbs heat from the cold side and release heat from the hot side. TEC has many advantages, such as no moving parts, no refrigerant, no pollution, no noise, high reliability, long service lifetime and so on. However, it also has some disadvantages. Its biggest weakne...(more)
Thermistors are thermal elements made of semiconductor materials. Resistance value of thermistors can vary with the temperature of resistor bodies. Thermistors can be divided into three types: positive temperature coefficient thermistor (PTC), negative temperature coefficient thermistor (NTC) and critical temperature coefficient thermistor (CRT). NTC thermistor has the following advantages: (1)High sensitivity The absolute value of its temperature coefficient resistance is greater than that of t...(more)
A low DC voltage is added on the both sides of thermoelectric cooler ( TEC ) and heat will flow from one side of the component to the other side. At this time, the temperature on one side of TEC will decrease and the temperature on the other side will increase. It is noteworthy that as long as the current direction is changed, the heat flow direction can be changed. So a TEC can realize two functions, cooling and heating at the same time. TEC can be used for precise temperature control. Whats mo...(more)
High voltage power module is a kind of a power supply, which can be directly mounted on circuit boards. Power module can supply power for integrated circuit, digital signal processor, microprocessor, memory and other digital or analog load. Generally, this module is called load point power supply system or point power supply system. Power supply has been widely used for switching equipment, access devices, mobile communication, optical transmission, microwave communication, router and so on. Our...(more)
Thermal silicon is generally called heat conduction RTV adhesive, which is cured at room temperature and has a certain adhesion performance. Thermal silicon is a kind of silicone rubber. If it is exposed to air, it will be cured and it will be very difficult to separate the bonded object. Thermal grease is a kind of heat-conducting medium, which is based on organic silicone as raw materials. It has non-toxic, tasteless, non-corrosive, stable chemical and physical properties, excellent thermal co...(more)
In last article, some types of laser drivers have been introduced, low noise laser driver and constant current laser driver. This paper aims to the other two types laser drivers , high voltage constant current laser driver and AC input laser driver. III. High voltage constant current laser driver High voltage constant current laser drivers include two series, ATLSXA212 and ATLSXA214. Both of them have high input voltage than other laser drivers in ATI. ATLSXA212 has an input voltage between 4.75...(more)
