Is the MOSFET the same as the thyristor drive circuit?

Their drive circuits are essentially different, first of all, the MOSFET is usually divided into junction MOSFET and insulated gate MOSFET, and the thyristor is usually divided into one-way thyristor and bidirectional thyristor (thyristor is also called thyristor, which can be divided into one-way thyristor and bidirectional thyristor), among which the insulated gate MOSFET is also called MOS transistor (there is a kind of MOSFET and transistor hybrid device called IGBT, commonly known as gated tube, the driving circuit of the device is almost the same as the driving circuit of the MOSFET), this drive belongs to voltage driveIn most applications such as power output and power conversion, it is best to use PWM (pulse width modulation) signal to control, and the rising edge of the square wave input to the gate is required to be steep (also known as totem pole output), and there must be a certain transient driving ability (because the gate of the MOSFET is equivalent to a capacitor, when the transient power of the driving signal is not enough, its original waveform will be changed, usually equivalent to an integrator), and when it is required to be turned on, the gate voltage should be about 10-20V higher than the source pole, The typical value is 15V, and in order to ensure that the MOSFET is turned off reliably, the voltage should be -15V at this time, in practical applications, in order to reduce the excessive power consumption of the FET or prevent its damage, it is generally necessary to add such as overcurrent protection and related absorption circuits, and try to achieve the same working frequency of the FET and the resonant frequency of the load, the typical application is the induction cooker, the current flowing through the furnace (plus ** circle) and the current flowing through the absorption capacitor are both very large, but the phase is different, cancel each other, The total current after superposition is smaller, i.e. the current flowing through the FET (IGBT in practice) is smaller. The following diagram shows a typical drive circuit for a MOSFET:

When there is a trigger signal, due to the strong positive feedback, it has been turned on, when the gate voltage is higher than the anode voltage or the anode, the cathode voltage difference is less than a certain value, the positive feedback will fail, that is, the silicon can be controlled to be reset, under normal circumstances, the gate voltage will not be higher than the anode, so the thyristor is a semi-controlled device that cannot be turned off, and it cannot be turned off by the gate when the conduction is triggered. The FET is a fully controlled device that can be switched off by a gate. The following figure shows the thyristor structure and its typical driving circuit:

1. Widgets are different:

The source S, gate G, and drain D of the MOSFET correspond to the emitter E, base B, and collector C of the thyristor, respectively, and their functions are similar.

2. Magnification factor:

The MOSFET is a voltage-controlled current device, which is controlled by VGS, and its amplification coefficient GM is generally small, so the amplification ability of the MOSFET is poor; A thyristor is a current-controlled current device that is controlled by an IB (or IE) IC.

3. Input resistance:

The gate of the FET hardly takes current (ig 0); When the thyristor works, the base always has to draw a certain current. Therefore, the input resistance of the MOSFET is higher than that of the thyristor.

4. Different performance:

MOSFETs have only many sons involved in conducting electricity; The thyristor has two kinds of carriers, polyon and fewton, which are involved in conduction, and the concentration of few sons is greatly affected by temperature, radiation and other factors, so the temperature stability and radiation resistance of FETs are better than those of transistors. In the case of large variations in environmental conditions (temperature, etc.), MOSFETs should be used.

First of all, in terms of structure, one is a 4-layer structure and the other is a 3-layer structure, which may not be very intuitive.

Then in the application, the field effect switch is switched on and off through the G level, for example, the G level is turned on if the level is high, and the low level is cut-off. The thyristor is different, generally speaking, the thyristor G level is only responsible for controlling the on, as for the off, it is automatic, that is to say, he does not care after the G control is turned on, the cut-off is a k current is zero, and the automatic cut-off.

Summary. The naked eye cannot accurately distinguish between transistors, MOSFETs and thyristors, which are very similar in appearance. However, you can distinguish by the device designation or by the part number and package of the device itself.

For example, common models of transistors start with 2N and BC, such as 2N3904 and BC547; Common models of MOSFETs start with 2SK and IRF, such as 2SK170 and IRF840; Common models of thyristors start with SCR, TRIAC and DIAC, for example, SCR is actually an abbreviation for thyristor. In addition, the packaging of these devices varies, with thyristors typically available in low-profile, leaded packages, while transistors and MOSFETs are often packaged in packages such as TO-92 and TO-220. In summary, triodes, FETs, and thyristors can be distinguished more accurately by identifying device logos, models, packages, etc.

However, in order to ensure the correct understanding and use of circuits, it is also necessary to have a deeper understanding of their electrical characteristics, operating principles and applications.

The naked eye cannot accurately distinguish between transistors, MOSFETs and thyristors, which are very similar in appearance. However, you can distinguish by the device designation or by the part number and package of the device itself. For example, common models of transistors start with 2N and BC, such as 2N3904 and BC547; Common models of MOSFETs start with 2SK and IRF, such as 2SK170 and IRF840; Common models of thyristors start with SCR, TRIAC and DIAC, for example, SCR is actually an abbreviation for thyristor.

In addition, the packaging of these devices varies, with thyristors typically available in low-profile, leaded packages, while transistors and MOSFETs are often packaged in packages such as TO-92 and TO-220. In summary, triodes, FETs, and thyristors can be distinguished more accurately by identifying device logos, models, packages, etc. However, in practical application, in order to ensure the correct understanding and use of circuit sources, it is also necessary to have a deeper understanding of its electrical characteristics, operating principles and applications.

Then BN60 is a MOSFET. How is it not there those signs you mentioned above.

Dear, maybe you didn't buy it with those signs.

So how do you distinguish between these tubes.

If he is damaged, he can't measure it with a multimeter, and it is not known what kind of tube he is. How to replace it?

Dear, this kind of tube that can't be distinguished by the naked eye, you have to make a difference when you are loading, a type of regret in the kind of mark, otherwise it will be very troublesome when you change it later.

Ok thanks.

Is there a software that can be used to find out what kind of tube it is by entering the model number?

According to the query, there is no such software yet.

Hello dear, happy to answer your <>

Transistors and MOSFETs often have similar appearances, making it difficult to distinguish them with the naked eye. However, thyristor cores usually have different appearances and markings, so they can be distinguished by the following methods:- The thyristor usually has three pins, one of which is the "gate" and the other two are the "main pole".

The main pole is usually larger than the gate and the chip has a distinct package. Triodes and MOSFETs, on the other hand, usually have only two pins. - The thyristor pins are usually arranged in a straight line, while the pins of triodes and MOSFETs are arranged side-by-side.

There are usually some obvious markings on the thyristor, such as the word "scr" or "thyristor" or a slash mark. Triodes and MOSFETs usually do not have this marking. <>

MOSFET VS Triode 1 The source S, gate G, and drain D of the FET correspond to the emitter E, base B, and collector C of the triode, respectively, and their functions are similar. 2. The MOSFET is a voltage-controlled current device, which is controlled by VGS, and its amplification coefficient GM is generally small, so the amplification ability of the MOSFET is poor; A transistor is a current-controlled current device that is controlled by an IB (or IE) IC. 3 The MOSFET gate hardly takes current (ig