fLED as a clock source? - Electronic Circuits Projects Diagrams Free

HarveyH42 · 17th August 2007, 06:39 PM

Haven't tried it yet, but was thinking a TTL/CMOS clock source could be made using a cheap fLED a transistor, and resistor. Maybe not a permanent fixure in a finished project, but I don't own a signal generator, nor keep a 555 circuit handy (so easy to throw one together as needed). But thought it might be simple and useful, students might find a use as well.

Figured I'd post this first, and see its been done, before spending much time re-inventing. Have a huge list of things to do this weekend (huricane season is starting to get busy...).

justDIY · 17th August 2007, 07:01 PM

whats a "fled"?

this? http://www.solarbotics.net/library/c...e_t1_fled.html

Hero999 · 17th August 2007, 07:16 PM

Flashing LED?

It's pretty simple, just connect a flashing LED and appropriately sized current limiting resistor in series with the base of a transistor with a pull-up resistor connected from the collector to +V and the emitter at 0V. Don't use an LED as the clock if you need decent accuracy, they're worse than a 555 timer.

justDIY · 17th August 2007, 07:29 PM

how about just a momentary switch and a finger? tap tap tap your finger, presto a clock, and it has adjustable frequency!

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17th August 2007, 06:39 PM	(permalink)
HarveyH42	fLED as a clock source? Haven't tried it yet, but was thinking a TTL/CMOS clock source could be made using a cheap fLED a transistor, and resistor. Maybe not a permanent fixure in a finished project, but I don't own a signal generator, nor keep a 555 circuit handy (so easy to throw one together as needed). But thought it might be simple and useful, students might find a use as well. Figured I'd post this first, and see its been done, before spending much time re-inventing. Have a huge list of things to do this weekend (huricane season is starting to get busy...).

17th August 2007, 07:01 PM	(permalink)
justDIY	whats a "fled"? this? http://www.solarbotics.net/library/c...e_t1_fled.html __________________ If you don't have a planet, what good are gold bars? want to contact me directly? gmail gordonthree check out my project website: http://projects.dimension-x.net Favorite numbers: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

17th August 2007, 07:16 PM	(permalink)
Hero999	Flashing LED? It's pretty simple, just connect a flashing LED and appropriately sized current limiting resistor in series with the base of a transistor with a pull-up resistor connected from the collector to +V and the emitter at 0V. Don't use an LED as the clock if you need decent accuracy, they're worse than a 555 timer. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez And http://www.silicontronics.com, same screen name as here.

17th August 2007, 07:29 PM	(permalink)
justDIY	how about just a momentary switch and a finger? tap tap tap your finger, presto a clock, and it has adjustable frequency! __________________ If you don't have a planet, what good are gold bars? want to contact me directly? gmail gordonthree check out my project website: http://projects.dimension-x.net Favorite numbers: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0