Heres a simple easy to build hi power(if you use hi brightness leds) led strobe....

 

By "Hi Powered" what are the specs of the LED's used Vf and If.

 

Looks like about 20ma for each LED, but it only requires a few part changes to increase that.

 

I was trying to make the distinction between "high brightness" and "high power" LED's. High power LED are certainly highly bright, but high brightness LED's are not necessarily high power.

 

It's certainly a good circuit for heating up 470 ohm resistors.

 

Yeh, I don't get it. Why not put D1-D4 in series? What is the reason for the opto-isolator? Why not use a 555 timer?

 

I agree with the lack of necessity of the opto, but I would parallel 2 series LED's with 300 ohm resistors and not put the 4 LED's in series, not enough headroom for good current regulation, especially if run on batteries.

 

this started out as a simple go no go tester for optos.....mainly used when iv had an smps which either isnt working or working but no regulation(depending on design)...was built fairly quickley using parts i had to hand and is here for anyone to have a play with and change however they wish.....the leds were actualli obtained from the £1 shop ....they sell 6 lighters at a time with hi brightness leds in them which were used on this and the flash is quite bright using these.

 

Aha! Things are always so much different when you know the truth.

So, for an opto-coupler tester, I would probably use a 555 timer at about 2Hz and I would use a single LED as a working indicator.

For a high intensity strobe, I would delete the opto-coupler but still use a 555 timer to drive the LED string through a transistor buffer.

 

yes u could use a 555 but i had none to hand and building a 2 transistor osc with the components i had to hand worked fairly well and it was made reasonably small too.its already proved itself opto wise for testing...