Hi everyone

A common strobe flash circuit with brightess preset until now usually is using a fast thyristor (such as cr3jm) as the 'quenched' switch.
You may refer to the circuit here:

<------ (edited) the link doesn't work! please refer to the attachment below in latter post

This is a schematic of a strobe flash with brightness / intensity preset.
I'm only gonna describe the presetting concept roughly, hope it's ok with you all.

The circuit part below the main circuit will act as (presettable) timer to cease the flash from firing. Yes, the level intensity is actually determined by the period in which the flash should fire.
The main switch that make this stopping possible, is the CR3JM fast thyristor. Normally, a common thyristor would fail to disengage. That's why a fast one is used instead.

The situation is like this:
CR3JM is kinda rare, i can't seem to get it in my country. I've searched over the web and found online store that sell it, but i think it is too expensive for me (it's like @ $6.00 for 300pcs). Do you think it is?
I think maybe if there are more options on IGBT, the price would be less expensive. Do you think so?

Anyone who knows of any schematic or can draw one for me that uses IGBT as the main switch in place of the thyristor, please help me. I would really appreciate it.

I hope this will be of some use for anyone else who read this thread.
It sure is most helpful for me!
Thank you all!

 

The image shack link doesn't work.

Do I understand correctly, are you looking for less-than-$0.02 per IGBT in quantities of a few hundred? Such is likely unachievalbe. If price is your only reason for using an IGBT, then stick with the thyrsitor.

 

I too was unable to open the jpg file.

hgmjr

 

The image shack link doesn't work.

Do I understand correctly, are you looking for less-than-$0.02 per IGBT in quantities of a few hundred? Such is likely unachievalbe. If price is your only reason for using an IGBT, then stick with the thyrsitor.

thx thingmaker3 for responding

the thyristor cr3jm, it's $6.00 per piece and sold for bulk 300 pcs. i am still bargaining and the latest quote was $5.75 a piece sold for bulk of 100 pcs.

as a matter of fact, price is one reason, another is i'm afraid that the thyristor will be dicontinued of production, because some people say that it's obsolete already.

oh and i'm attaching the pic here. thx alot!

friendly,
robert

 

Not 300 for 6, but 300 at 6 each! I understand now. If it were me, I'd go through the catalogs looking for the least expensive MOSFET or IGBT that will handle 120% or more of the voltage & current.

 

Not 300 for 6, but 300 at 6 each! I understand now. If it were me, I'd go through the catalogs looking for the least expensive MOSFET or IGBT that will handle 120% or more of the voltage & current.

really? if you think so, my friend, i'll do just that.
can you help me with the schematic? i don't have any idea on using mosfet yet. in fact, the only mosfet i'm familiar with is the irfz44 and the series. only 40 volt max isn't it?

thx thingmaker3,
robert

 

http://www.vishay.com/mosfets/

http://www.onsemi.com/PowerSolutions/parametrics.do?id=809

http://www.fairchildsemi.com/sitesearch/fsc.jsp?command=eq&attr1=AAAFamily&attr2=MOSFET

https://ec.irf.com/v6/en/US/adirect/ir?cmd=eneNavigation&N=0+4294841672

 

thingmaker3, you're the best

i'll go through the links you suggested

many thanks my friend,
robert