Did this thread get edited or moved or something? Or did I respond to the wrong thread?

The post you replied to was removed by the poster. That's one reason why I try to quote the material I am responding to (don't always actually do it) so that if the post is deleted or edited that the context of my response is preserved.

 

The post you replied to was removed by the poster. That's one reason why I try to quote the material I am responding to (don't always actually do it) so that if the post is deleted or edited that the context of my response is preserved.

Thanks. Glad to hear it was a force beyond my control. Now where'd I leave the remote...

 

Since this is the homework and I moved it to homework help forum, the homework can't give you the direct answer, but you didn't say that this is the homework, and the circuit is easy to get from internet, so I kept the circuit.


You can google Persistence of vision and you can easily to get the answer, the others as old CRT used ?Hz, the movies used ? films/sec, city power AC110V/? Hz, AC220V/? Hz, the most important thing is you have to do the experiments and to try the frequency, it is not so hard, you just need to try it.

Whatever you try, using at least five times of the frequency that beyond the frequency with no blinking .

Actually it's not for homework, or i guess u can call it homework too maybe. This is part of my MSc project, which my main course is on semiconductor fabrication and so on and does not touch about electronic circuit even a bit. So I can only rely on my long forgotten basics of electronic learnt during school. Thanks to u and the others, I have an idea about it now.

Alright. If that's the case, I'll try order a number of resistors first and try varying them to get the needed frequency.

Thanks again.

 

If it is for any kind of course credit it is homework.

 

MSc = Masters of Science project?

 

MSc = Masters of Science project?

That's how I read it.

 

I just didn't think the project was any challenge for that type of degree. Color me surprised.

 

I just didn't think the project was any challenge for that type of degree. Color me surprised.

The circuit is just a small part of the project.Yup for you guys it's peanuts. But for one who got zero background in electronics it got just a little complicated.

 

This is the more simple approach, but it requires an inductor. Here is the wiki, go to images for schematics... These run for weeks on a small watch type battery... Since the oscillator runs at a very low voltage, it sucks everything out of the battery, even when the battery is below light level on the led.

https://en.wikipedia.org/wiki/Joule_thief

Jack