Controlling the firing angle of a Silicon Controlled Rectifier using Labview

[ayodeji]

Guys, I'm working on a project titled 'Controlling the Firing angle of a Silicon Controlled Rectifier using Labview' and really don't know how to go about this. I'm new to Labview and would need your assistance in implementing this....Please help!!!

 

[Sadegh.j]

scr firing angle

I did a project in Orcad Pspice and it was pretty much the same thing. I can give you the circuit if you want and then you can transfer it to LabView.

 

[ayodeji]

firing angle scr

Yes, I'll appreciate if you can give me the Circuit and I'll transfer it to LABVIEW...You can send it to me using gifting007@yahoo.com. Thanks

 

[TekUT]

maximum firing angle scr

May be also nice look at the project on this board to help also other people in similar stuff.

Regards
Powermos

 

[Sadegh.j]

circuit for firing angle of scr

The project is attached, as promised.

The project works perfectly well, I have tested it several time.

If it helps you, don't forget to press the help button.

Cheers

 

[ayodeji]

firing delay angle of scr

Thank you very much. I'll just take a look at it now and try to replicate it on LABVIEW. Cheers

Added after 5 minutes:

Pls what do I need to use to open the files. Is it Pspice?

 

[TekUT]

firing angle and circuit

Could you also post a circuit drawings?

Bye
Powermos

 

[kender]

find scr firing angle

Folks,

I don’t understand SCRs very well. That’s why I’m posting to this thread, you guys are well-versed at SCRs. I’m simulating a circuit that will be generating high-voltage pulses – sharp negative spikes from 100V to 0V and quick recharge back to 100V. Unfortunately, I can’ explain the simulation results:

* The red trace is the output. The green trace is the gate of the SCR. Why the output doesn’t fall at the first gate pulse?
* Why the output falls to 40V instead of all the way down to 0.7V?
* What could be the cause of these problems?
* Am I using the wrong component for the SCR? Could you suggest a good model for a generic SCR to play with?

Any enlightenment would be appreciated!

Thanks,
- Nick

 

[Sadegh.j]

scr pulse generator

Hi

I cannot remember SCRs well as I passed industrial electronics about three years ago.

But off the back of my head, the followings can be the reasons:

1) What turns off an SCR is current and not voltage, change the voltage pulse generator to a current pulse generator.

2) I remember when I was doing the course project, I tested many models of thyristors before finding the right one. I cannot remember what the model name was, but you can open the attached file and you will sure find what you are looking for there. It took me about a month to do it, since there was a bit of pulse techniques needed for the ramp generator and the rest of the story, so I assume the file to be complete and with no mistakes. ( I got full marks for the project that day), so I think the used thyristor is correct. (I might have even changed the parameters)

3) The attached file can be opened using Orcad Pspice.

4) You can always edit the model of what you are using. It is very easy.

Cheers

 

[kender]

firing angle scr

Sadegh,

I've looked at your circuit. The model for the SCR that you're using (C223M) produces more reasonable results in my circuit. Unfortunately, I can't find the datasheet for it. If you have this datasheet, could you upload it?

Cheers,
- Nick

 

[FvM]

firing angle circuit of scr

@ Kender: Some comments on your simulation results.

I'm using a small SCR (ST P0102M) to generate 500V falling edge pulses. It works fine, but some limitations have to be considered.

A SCR has a considerable turn-on delay, in my application it's around 1 us. It partly depends on the trigger current level, but can't be reduced below some limit.

The turn-off delay is even larger. When the anode current has dropped below the holding current threshold, it takes some time before the charge carriers have recombined. Applying a voltage during this time interval would cause the SCR to latch again.

The other point is, that the static anode current in your circuit would immediately blow the SCR. A real SCR wouldn't stand the current longer than some us.

 

[kender]

firing angle of silicon controlled rectifier

BTW, here's a waveform recorded from a gate of an SCR in a 1977 Panametrics pulser. The width of the spike in the beginngin of the hump is 9ns or less.

- Nick

 

[Sadegh.j]

firing angles for scr

Hi Kender

Sorry about my late reply.

As I said, the project was done two years ago and I cannot remember the details of it. I am sure you can find the data sheet online.

You can adjust the used model depending on your needs.

Regards

 

[narsi_chinna]

Firing angle of SCR

can anyone plz help me in my project regarding firing pulses genation using labview(6008)

 

[ramyakv11]

i am working on a project to fire a thyristor using LABVIEW . can somebody tell if it is possible and if yes how?