Help me with a design in which SCR controls some LEDs

[nasirasim]

SCR Diode

Hello Experts.
I want to know the function of SCR even if i know some thing about this. Actuall I want to controll several LEDs with only two or three switche. I want to switch on first LED and then "control" goes to next LED if I want to start is I press first switch otherwise I press second switch and control goes to Next LED.
Please help me. thanks in advance

 

[smartsarath2003]

Re: SCR Diode

Why do you want to use a SCR to control LED's.
You can use a microcontroller to check the no of switch On states and switch on ur led's.
You can also use a decoder, if you want to use few switches and more outputs
SCR's are mostly used where you need to leave ckt ON once it is triggered. Also you need another switch to turn off SCR.

 

[IanP]

Re: SCR Diode

SCRs have more use in AC circuits as in DC applications there is no way of switching them OFF except of turning the supply off ..
If you want to boost current to cntrol LEDs use transistors or gate-drivers (buffers) ..

 

[nasirasim]

Re: SCR Diode

Why do you want to use a SCR to control LED's.
You can use a microcontroller to check the no of switch On states and switch on ur led's.
You can also use a decoder, if you want to use few switches and more outputs
SCR's are mostly used where you need to leave ckt ON once it is triggered. Also you need another switch to turn off SCR.

Then please tell me the any microcontroller which I can use to control up to 200 LED with my comptuer's parrallel port. I want to display eny thing written in my textbox. Thanks

 

[IanP]

Re: SCR Diode

To connect 200 LEDs to your PC you may have a look at MAXIM port expanders:
**broken link removed**
(MAX 7300 is a 28-DIO port expander, MAX 7301 - 20-DIOs)

 

[smartsarath2003]

Re: SCR Diode

I don't have any idea controlling that many no of LED's with microcontroller.But if its smaller in number 10-15, you can use PIC
I think above Maxim application note is useful. From 28 pins,look for other ways expanding using serial in parallel out shift registers/decoders depending on ur application

 

[yeechyan]

SCR Diode

You can use some programmable peripherals to expand the ports. One of the simplest is 8255.

 

[dreamcard]

Re: SCR Diode

SCRs are used to control the AC power flow.They often operate at very-high current environment