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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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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SCR gate drive options when optotriacs not suitable due to high voltage of 1600V
I am designing a 3-phase circuit to switch 1kV 50kW using thyristor pairs.
The circuit is simple on/off switch, and needs to be simple as possible. I thought this precludes the use of pulse ...
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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 ...
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Series thyristor circuit
I want to build a pulsed energy source and consider up to 6 kV for the storage capacitor voltage. The application is similar to a defibrillator but not for medical purposes. So any insights into 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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Thyristor T901N
The thyristor T901N in the Sinamics SL150 datasheet indicates constant operation limits based on temperature. In the datasheet, the continuous operation limits for this thyristor are as follows:
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Can I use thyristor in place of pass transistor withvoltage regulator
I am making a circuit using an LR8 voltage regulator, and because the current may go over the recommended 10ma I will be putting a pass transistor to carry a little more current. The one I see most ...
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MOC3020X phototriac: Does minimum latch current affect other specs of the IC?
I use MOC3020 IC to control a thyristor for AC mains voltage. My project works as expected and I would like to make an improvement on the current consumption, as I saw that there are other MOC302X ICs ...
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Why is the SCR in this circuit switching off even though current is still above th holding current?
I am designing a circuit that controls DC power to a load through the use of SCR thyristors. I have been testing things out using the CLA20EF1200PZ part from Littelfuse. It has a 25 mA holding current ...
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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 ...
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Is It Possible To Choose a Higher Holding Current When Designing SCR?
I'm looking at this data sheet: SCR data sheet on Digikey
This device seems perfect for what I want to do, with 1 exception:
The holding current is way too low.
Various forums have suggested that (on ...
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Zero Crossing Detector for Microcontroller
Im trying to design a control circuit for charge a battery, for this i will be controlling the battery charge by a 40tps ( SCR ), phase control. So my little understanding for what i read is that i ...
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For sufficiently low duty cycle, can you get away with driving SCR above rated current as long as A^2 * s are maintained?
I'm wondering if the A^2-s rating of an SCR is what ultimately decides whether a given current for a given time is okay, even if the data sheet does not list such a number.
For instance, right now I ...
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SCR based rectifier vs IGBT based rectifier
I am wondering what is the difference in performance of rectifiers when used with SCR and IGBT.
I searched on internet but all i can find is that IGBT is voltage triggered and SCR is current pulse ...
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Thyristor gate triggering issue
We are using an MOC3041 to trigger the gate of a thyristor (BT155Z-1200TQ). We use the circuit design from the datasheet of the MOC3041 (Figure 12: Inverse−Parallel SCR Driver Circuit).
We detect zero ...
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How to make a driver circuit / trigger circuit /gate circuit for SCR?
Ii would like to ask you for help to understand the SCR, thanks in advance!
I also hope this question helps another to understand this device too
I have read about SCR in Boylestad book but it's ...
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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 ...
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What is Vac(peak) in this question?
Bit confused at what Vm/Vac(peak) is. Either 230V or 325V. rest seems simple
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Can an SCR conduct backwards in large amounts while the gate is asserted?
I am driving an inductive load and have a situation where an SCR will be forward biased but conduct in reverse. Can it do that if I strobe the gate the entire time I want it to conduct in reverse?
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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 ...
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Requesting clarity on the di/dt rating of thyristors
simulate this circuit – Schematic created using CircuitLab
I have a general question about thyristors. I know that the di/dt limitation of thyristors is due to high currents flowing through ...
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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 ...
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Why does a MOSFET or IGBT's surge current rating stop increasing with decreasing pulse width beyond a point, unlike thyristors?
Thyristor
The surge current rating of a thyristor increases as the width of the pulse decreases. For a single non-repetitive pulse, it's not uncommon for a thyristor to have a surge rating that is 10x ...
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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 ...
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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 ...
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Floating high-side thyristor switch is destroyed by massive gate voltage undershoots
I'm building a capacitor discharger with a thyristor for high-voltage impulse generation into an inductive load. To make the circuit easier to use, I wired the thyristor as a high-side switch. Then I ...
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How does a TRIAC work?
I’m trying to understand the concept of a TRIAC. I’ve heard that a TRIAC is made with 2 SCRs (thyristors) connected in anti-parallel.
But in the diagram I looked at, it looks like two SCRs were ...
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Calculating reactors for parallel connection of thyristors (SCRs)
I have been looking for more information on how to connect two thyristors in parallel in order to balance the load. From what I have found there are two options: either using balancing resistors, ...
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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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Connect two thyristor in parallel
I have 2 BTW69-1200 thyristor
Vrrm = 1200 V
Irms = 50 A
I tsm (Non repetitive surge peak on-state current) = 610 (8.3 ms) - 580 (10 ms)
Here is the datasheet
https://pdf1.alldatasheet.com/datasheet-...
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Thyristor external power supply
I am trying to make a kicker solenoid. My circuit is:
12 V battery connect to DC step up booster 300 V
diode
thyristor BTW69-1200 with external circuit (battery 1.5 V - resistor 1/4 W, 39 Ω)
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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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Why is my SCR controlled by a photodiode pulsing when supplied with high voltage
I am working on a circuit which when a photogate (consisting of a photodiode and a corresponding LED) is interrupted, an SCR is triggered which discharges a capacitor through a solenoid. I built and ...
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Basic thyristor questions TYN1225
I have the component TYN1225 that I believe to be a thyristor.
I just read about thyristors that are described as rectifiers enabled or non enabled on demand.
According to what I read and understood ...
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Why do NPNP thyristors remain on but NPN transistors don't after gate voltage is removed?
My understanding is that when a positive voltage is applied to the gate in a thyristor, the P region can store excess electrons which can then move to the n region. I don't understand why it continues ...
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Thyristor holding current Vs VD (turn off voltage)
I am working on a LC discharge which use a thyristor when the C capacitor voltage exeed a reference voltage. The capacitor is charged by a flyback converter. The flyback converter is stopped during ...
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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 ...
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How to interpret thyristor's minimum load current?
I want to switch on/off a variable resistive load of 1mA to 150mA at 500VAC with a microcontroller.
simulate this circuit – Schematic created using CircuitLab
The chip ...
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How to make a MHz-fast, 5 volt thyristor with discrete components? [closed]
Off-the-shelf thyristors are optimized to switch at mains frequency, - 60 Hz in the U.S.A. In my application, I need MHz speeds, 10 to 20 watts, 5 to 10 volts.
Is it possible to emulate thyristor ...
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How do I calculate the potentiometer value for the controlling of Alpha angle of a phase control IC? [closed]
The datasheet suggests to use a 10Kohm pot to control the Alpha angle, however no matter how much I try I can't control it. I used 1Mohm pot instead and now I can control it more, but still with very ...
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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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SCR inverter (thyristor H-Bridge) schematics/working principle?
Several online articles mention the so-called "Single phase SCR Inverter". Sample schematic is attached below.
Source: Single Phase Full Bridge Inverter Explained | Electrical Concepts
In ...
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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 ...
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Gate Drive Circuit of an AC Voltage Controller
The circuit shown is used to control the gate drive of an AC Voltage Controller. I am trying to understand the functions of each of the parts and cannot understand the need of the NPN transistors Q1 ...
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What is the role of D2 and D3 in this circuit?
Explanation of the circuit :
This is a simple battery charger based on SCR is shown here. Here the SCR rectifies the AC mains voltage to charge the battery. When the battery connected to the charger ...
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Why is there a minimum current in a class-a chopper?
$$i_o(t) = {{{V - E} \over {R}} \cdot (1-e^{-{R \over L}\cdot t}) + I_{min} \cdot {e^{-{R \over L}\cdot t}}}$$
Where is the minimum current from, and why are we dividing by R?
This is the link
https:/...
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Why does this circuit with thyristors ignore the pulse provided at the gate terminal
Here's the circuit:
T1 and T2 are two thyristors where i provide pulse at their gates.
Here's the output:
For some reason Vout follow Vin before the pulse at T1 happens when Vout before the pulse ...
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Can I put high voltage thyristors in series & ZVS to handle MHz frequency resonance?
I'm trying to scale up a circuit that calls for a MOSFET and a ZVS to be capable of dealing with high frequencies (1-20 MHz.)
I'm aiming to crank it up to 10 kV and would prefer the systems in series ...
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Why do we use thyristors instead of regular diodes for high voltage direct current?
Usually, power lines over large distances use alternating current (AC). However, in some cases, direct current (DC) is also used, as high voltage direct current (HVDC), where the high voltage is used ...
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