Questions tagged [thyristor]

A three-terminal semiconductor device consisting of four layers of alternating type (N or P). The main terminals are the anode and cathode, connected to opposite ends of the four layers. The third terminal is called the gate, and a current trigger at the gate causes the device to conduct if it is forward biased.

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Resonant frequency of a three phase thyristor rectifier

I am trying to inspect how my circuit behaves at operating points around resonant frequency. Is resonant frequency simple equal to 1/(2Pisqrt(LC)) = 1/(2pisqrt(590uH240uF)) = 423 Hz (see the circuit ...
145 views

What happens when I pass really high current through the gate of a thyristor?

I have a thyristor that requires 120mA(from datasheet) gate current for triggering. I'm giving DC to gate and AC is connected across anode and cathode. Now, according to theory, with dc triggering ...
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1 vote
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Quantifying the reduction in a thyristor's turn-off time in response to increasing reverse voltage: Seeking data or graphs

From a previous question of mine (here: What factors affect a thyristor's "circuit commutated turn-off time"?), which was asked about 5 years ago, a user presented this very helpful ...
1 vote
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Is my basic coil gun schematic correctly wired?

Recently, I came up with the idea of integrating a coil gun into a marble machine to accelerate an iron marble. I've done a fair bit of research into other people's projects, and ended up mixing what ...
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How can I control a DC circuit via a high voltage AC signal?

I have a low voltage circuit of 9V DC supply voltage and a bunch of LEDs, and another circuit with 50V AC voltage. I want the DC circuit to work only if there is current flowing in the AC circuit. I ...
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Connecting the GND of an isolated circuit to the positive side of a 450V transformer output

I moved to a new company that makes very big old-style controlled rectifiers. They asked me to make a new modified, and enhanced thyristor-controlled rectifier. The strangest problem I faced is that ...
1 vote
1k views

interfacing MOC3021 with high current back to back scr

I want to drive two back to back thyristor with moc3021 for soft starter.Here is the circuit: This circuit works for medium power SCR such as BT152,But I want to drive a couple of disk thyristor that ...
1 vote
41 views

Is zero loss turn-off possible for thyristors?

Consider this very basic circuit: simulate this circuit – Schematic created using CircuitLab Don't mind the values - they don't matter, as this question is conceptual. Imagine that Vcomm is ...
1 vote
65 views

Does a thyristor experience loss if it is switched at zero volts?

I have developed a circuit that uses a capacitor's voltage to reverse bias a thyristor. The voltage to reverse bias it is only about 10% of its off-state blocking voltage. I am confused how I ...
1 vote
500 views

Electric heating for glass melting furnace

Some furnaces use electricity for glass melting. Low voltage and high amperage power is passed through the molten glass through 2 molybednum electrodes dipped into the glass. The molten glass acts as ...
1 vote
705 views

thyrsitor leakage

I have built a circuit to switch a thyristor* on and off . The circuit is like the circuit below. when the gate is on all is right and the device is latched when the gate voltage is removed , but ...
1 vote
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What is a Thyristor Switched Series Capacitor (TSSC)?

I'm struggling to understand the physical difference between the Thyristor Switched Series Capacitor (TSSC) and the Thyristor Controlled Series Capacitor (TCSC). From this book, I understand that a ...
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Are Bridge AC to DC Rectifiers using thyristors still considered Linear Rectifiers considering their switching mechanism of action?

While I tried not to make the title confusing, Whether if the question is about Non-Linear/Linear PSUs or just the Rectifier circuits, I believe This one covers both matters. Considering that the ...
87 views

Unable to fire thyristor simscape electrical matlab simulink

Hello, I am unable to fire a thyristor on simscape. I have tried to connect the gate to a pulse generator with a simulink-ps conversion symbol but it doesn't work ( the lines will not connect). I ...
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Is it possible to make a halfbridge coilgun with high side IGBT and low side SCRs?

In a rather simple coilgun, the problem of freewheeling current from the coil is solved with a diode in parallel with the coil. The energy of the reverse current is wasted this way and even slows the ...
111 views

Budget friendly battery charger controlled by phase angle ( SCR )

My circuit circuit is below so you can understand what I'm saying. I want to make a lead battery charger that can control the charging voltage and current (no discharge.) I have a circuit that ...
98 views

Three-Phase Thyristor Bridge Converter Simulation on Matlab

I am looking for a 24 pulse rectifier to power an electrolyser using a universal thyristor bridge from matlab. I am using a phase shifting zig zag transformer for this. The transformers are shifted by ...
49 views

Do commercial products exist for lab-scale thyristor triggering?

Hello fellow stack exchange members! We're excited about our novel high-voltage voltage-source-converter design that utilizes SCRs/thyristors and commutation circuits. We're now looking to build a ...
64 views

Help with this 3-phase thyristor triggering board

I need a triggering board which is able to drive thyristors such as (s8006l), and I found this board on Aliexpress which might be the hidden gem I am looking for. enter link description here enter ...
69 views

What is the most efficient circuit to control a 3-phase controlled rectifier circuit with the ability to control the firing angle?

I am trying to design a board to control a 3-phase full wave rectifier with the ability to control the firing angle (alpha) through a potentiometer or a selector, and I was wondering what are the most ...
149 views

Difference between thyristor I(tsm) and I T(AV)

For example I have a capacitor send intermittent pulses to a coil send about 85A for few msec then off for 3-4 seconds (for 5mins) I was looking for a scr to switch it i found 40tps12 thyristor https:...
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Replace transistor-latch with thyristor: is my circuit correct?

Please consider the following two circuits: On the left, is a transistor-latch using a PNP and an NPN transistor. I'd like to replace those two transistors with a thyristor, mainly to get a little ...
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Digitally adjusting AC voltage for a motor

Basically I have an extraction fan motor that runs full speed at 230V, at 130V it runs around half the speed. The original chip allows switching between few voltages (and therefore, fan speeds) upon ...
1k views

Thyristor Power Loss

i want to calculate the power loss of a thyristor with datasheet's parameters and i found this formula from here Application Note: Conduction loss: Total loss: How can i calculate the power loss if ...
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Thyristor controlled 3-phase heater control, spiky current

Lets say you have 10 thyristor controlled heaters in a 3-phase system. The control of these thyristors is sync'd, so the current draw is spiky (all of the heaters draw current from the same phase when ...
119 views

Rectified signal from three phase rectifier circuit

I'm trying to simulate this circuit This is the implementation I'm getting this output signal, that is close to what you would expect from a rectifier. In this image α = 0, α1 = π/6, α2 = 5π/6 and ...
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Three phase rectifier with thyristors not working as expected

I'm trying to simulate the following circuit with a resistive load: The control circuit provides three signals, and are the turn on signals for the thyristors: the first one (yellow) α1 = α + π/6: ...
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common circuit to turn on/off ac motor of 110V AC or 230V AC using MOC3041 and BTA16 Resistor calculation

I am building a common circuit to turn on/off ac motor of 110V AC or 230V AC using MOC3041 and BTA16. How do i calculate both resistor value R and Rg ( With Wattage ). For accurate control of TRIC. ...
299 views

Single-phase thyristor full bridge rectifier vs three-phase thyristor full bridge rectifier

For Single-phase thyristor full bridge rectifier compared to a three-phase thyristor full bridge rectifier, with regards the input current harmonics, does the three- phase rectifier have an advantage ...
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Transient voltage supression for high voltage Thyristor or Avalanche TVS

I am making a high voltage 240 VAC 60Hz voltage measurement front end and is in need of a transient suppression device. According the a table in wikipedia. Avalanche and Thyristors are the only ...
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Thyristor leaking AC? Reading thyristor code?

I'm refurbishing an automotive battery charger. It uses a full-wave rectifier in combination with a thyristor (which I think is acting as output cutoff). The charger output has is the correct DC ...
58 views

One button circuit with thyristor, controling power suply

Please forgive my lack of knowlige. I need to make circuit with one button(normaly OFF, ON while pressing) using thyristor. This circuit will be connecting and disconnecting raspberry pi and bunch of ...
134 views

How to increase the peak current to 12 kA in my circuit?

I am simulating a circuit with a capacitor bank. I am getting maximum peak current to 8.8kA. I need to know how can I increase the peak current to 12-15 kA without increasing the input voltage. The ...
30 views

Measuring Forward Impedance of a pulsed drive circuit

Background: I recently built a thyristor driving circuit to supply a set number of trigger pulses to my thytratron (tetrode configuration). The spec sheet for the thyratron requires that my driving ...
52 views

How do I calculation to see if Thyristor complies with DO-160G indirect lightning protection

I have been working with TVS diode and found that the capacitance of tvs diode is large; therefore, I will not be able to use tvs diode. Thyristor, on the other hand, has low capacitance for high ...
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Voltage and amperage requirements for resistance heating of glass

I am planning to introduce electric heating/boosting in my glass melting furnace. The present temperature of the glass is around 1200 deg C and I need to raise it up to 1300 deg C. I am trying to get ...
62 views

Why on shutdown the SCR can be compared to a power diode?

I have this as a homework question and can't seem to find the answer in my notes, book or internet. I know they will behave similarly when there is a reverse polarity on both, but the way my professor ...
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Average output voltage of single-phase thyristor-controlled bridge converter

This question is highly related to this one but I don't find the answers satisfying. I'm a bit confused about the equation for the DC output voltage of phase-controlled bridge rectifiers. \\$V_{o_{...
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3 phase fully controlled rectifier

A 3 phase fully controlled bridge converter is fed through star-delta transformer. The converter is operated at a firing angle of 30 degrees. Assuming the load to be a RL load and load current to be ...
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simulation (in Falstad's app) of thyristor using transistors fails

I am trying to simulate thyristor behavior with transistors PNP and NPN but it fails (is it a bug of app?). When lower switch is open(and was never closed) and upper closed then current flows through &...
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6 thyristor scr

I have three thyristor and three diodes scr working inside welding machine and drived by good pcb (working very good ). The problem is that I need to replace the three diode by thyristor to use all 6 ...