Utsource-Electronic

TDA7294 contains a variety of functions such as pre-op amplifier, final power amplifier, temperature protection, short circuit protection, and mute control. The power amplifier circuit composed of TDA7294 has simple peripheral circuits, easy to manufacture, high input impedance (20K Ω ), input sensitivity 750mV, voltage gain 32dB, power supply voltage range ± 25~40V, quiescent current 50mA. When the load impedance is 8 Ω , the output power can reach 100W. In actual production, a large enough heat sink and a power supply with sufficient power should be ensured. If you need to increase the voltage gain of the overall circuit, you can change the ratio of R3 to R2. Voltage gain: A=20lg (R3/R2) dB. Don ’ t pursue too high voltage gain, so as not to cause uncontrollable self-oscillation. To have a high voltage gain, you need to add a pre-amplifier. As shown in the figure below, it is an easy-to-make 100-watt power amplifier circuit composed of TDA7294.

pc817 is a type of optocoupler. The optocoupler (opTIcalcoupler, abbreviated as OC in English) is also known as opto-isolator or optocoupler, abbreviated as optocoupler. It is a device that transmits electrical signals through light.   The working principle of pc817: PC817 is a device that encapsulates infrared light emitting devices, infrared light receiving devices and signal processing circuits in the same socket. When the input electrical signal is applied to the input light emitting device LED, the LED emits light, the light receiving device receives the light signal and converts it into an electrical signal, and then directly outputs the electrical signal, or amplifies and processes the electrical signal to a standard digital level output. The conversion and transmission of "electricity-optical-electricity" are realized. Light is the transmission medium, so the input end and the output end are electrically insulated, which is also called electrical isolation.   The dete...

TL431 is a precise voltage regulator integrated device. Because TL431 has high control voltage accuracy and relatively small temperature coefficient, it can provide accurate reference voltage. This device can also be seen in switching circuits such as battery car chargers and induction cooker circuits. This kind of precision voltage reference integrated circuit is widely used. Now I would like to give my friends a brief introduction to this integrated circuit commonly known as a voltage regulator.   Introduction to TL431 This kind of integrated circuit has three forms, one is like a plastic-encapsulated triode, and its package form is T0-92A. It has three pins, with the plane facing itself, the first pin from the far left is represented by R, which is the voltage sampling pin; the second pin is represented by A, called the anode; the rightmost lead The foot is denoted by K, which is the control terminal. The second type is in the form of integrated patch, and its package is SOJ-8 t...

  The LM2596 module adopts the switching regulator chip LM2596, and the solid capacitor is integrated with 220uf/35V. Input: DC 4-35V (The input voltage must be 1.5V higher than the output voltage.) Output: DC 2-30V voltage is continuously adjustable, and the maximum output current of high efficiency is 3A. The LM2596 series is a 3A current output step-down switch integrated voltage regulator chip produced by Texas Instruments (TI). It contains a fixed frequency oscillator (150KHZ) and a reference regulator (1.23v), and has a complete protection circuit and current Limits, thermal shutdown circuits, etc. The use of this device can form a high-efficiency voltage stabilizing circuit with very few peripheral devices. Provided are: 3.3V, 5V, 12V and adjustable (-ADJ) and other voltage grade products. In addition, the chip also provides external control pins for working status.   The main features of LM2596 series switching regulator integrated circuits are as follows: 1. Outpu t v...

The precision bridge isolation amplifier circuit composed of ISO100 is mainly used in weighing and pressure measurement systems. ISO100 is a small and inexpensive optical isolation amplifier circuit, which is excited by LED light, and the photoelectric receiver tube receives and transmits. The picture shows the application of ISO100 in the precision bridge isolation main amplifier circuit. The bridge outputs a unipolar signal of 0 ～ -l0mV, which is amplified by 100 times by the INA101 high-precision instrument amplifier, and then sent to the unipolar input end of ISO100 through a 100k Ω resistor Rl. In order to ensure the linear operation of ISO100, the instrument amplifier of INA101 The output must be lower than the negative value of -2mV. Because ISO100 is in a unipolar amplification state, its internal constant current source is useless for the amplified signal. Here, the output of pin ⑧ is grounded, and pin 16 is composed of I/U through the precision operational amplifier OPA177. T...

Electronic component : Device products: Relay Relay is an electronic control device. It has a control system (also called an input loop) and a controlled system (also called an output loop). It is usually used in automatic control circuits. It actually uses a smaller current to control the A kind of "automatic switch" with high current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit. Automotive Relay/Signal Relay Solid State Relay/ Intermediate Relay Electromagnetic relays/reed relays Wet Reed Relay/Thermal Relay Step relay/high power relay Magnetic Latching Relay/ Polarized Relay Temperature relay/vacuum relay Time relay/hybrid electronic relay Delay relay/other relays D iode A semiconductor diode is also called a crystal diode, or diode for short; it is an electronic part that only transmits current in one direction. It is packaged by a PN junction plus corresponding electrode leads and a package. Switching dio...

LM317 working principle As an integrated three-terminal voltage regulator block with variable output voltage, LM317 is a convenient and widely used integrated voltage regulator block. There are many models of the 317 series voltage stabilizing block: for example, LM317HVH, W317L and so on. Electronic hobbyists often use the 317 regulator block to make a regulated power supply with variable output voltage (the basic form of the circuit is shown in the figure below). The output voltage of the regulated power supply can be calculated by the following formula, Vo = 1.25 (1 + R2/R1). Just looking at the formula itself, the resistance values of R1 and R2 can be set at will.   However, as a formula for calculating the output voltage of a regulated power supply, the resistance values of R1 and R2 cannot be set arbitrarily. First of all, the output voltage range of the 317 regulator block is Vo=1.25V-37V (the 317 regulator block with high output voltage, such as LM317HVA, LM317HVK, etc., ha...