Design for Sound Operated Light Circuit

You could use a seperate/additional amplifier.

You can use your hi-fi system: Use one speaker output for a speaker, if you want to hear it and connect a 220 ohm resistor and a LED in series to the other output. Adjust balance and loudness that you can hear something in the desired loudness and see the LED light, if there is a signal.

A incandescent bulb is not a good idea, because turning it on and off often, will wear away it fast.

On a sunny day (Thu, 28 Aug 2008 20:03:34 -0700 (PDT)) it happened Maddy wrote in :

• 9V + 9V | a | LED R3 | k ----| C1 + c | c audio line level ----|||-----------b NPN |--b NPN | | e Q1 | e Q2 /// R1 | | | | R2 | /// | | | | /// | |_____________________|

R1 22k R2 82 Ohm R3 2k2 C1 10uF / 3V Q1, Q2 transistors: almost any NPN si, for example BC548, BC109, etc.

This can be run from a 9 V battery. It is in fact a very sensitive AC detector.

Optinally one can connect a capacitor from the collector of Q1 to ground.

I learned the Morse long ago, but I really don't think I could easily convert light to letter very easily. One problem for me would be looking at the light and looking at my sheet. I know it would be a huge problem watching several sources mixed together.

greg

I think you will find that Morse is more easily/quickly comprehended audibly (or in mechanically/electrically written text) than visibly. In situations where only visible communication is possible, reliable Morse transmission speed may be reduced to as much as 1/3 that of other methods. It's also visually exhausting for longer messages - wearing out the eye's point-perception capacity, quite rapidly.

RL

Jan Panteltje wrote:

While I applaud your effort, my intuition is

2) As he is MULTI-POSTING news: snipped-for-privacy@l33g2000pri.googlegroups.com from Google, he is quite clueless and will see *this* blob (in a proportional font)

Frank's answer (and mine) leaning toward COTS stuff seems more apt. Even Bill Bowden's response in the s.e.b thread (to use a step-up transformer) seems over the OP's head.

That's what the evidence says to me. Of course, I could be wrong.

FWIW, you're one of about two total google posters I've ever seen come back to read responses. I think they expect the answers to show up under their pillow or something. ;-)

Thanks, Rich

On a sunny day (Fri, 29 Aug 2008 10:43:58 -0700 (PDT)) it happened JeffM wrote in :

Sure, just for fun, here is the ltspice version ftp://panteltje.com/pub/ac_detector_1.gif

You will see about 11mA LED current for 1V input @ 1000Hz. The LED brightness can be set by the volume control. As the pulses are 1000Hz, that seems like constant 'on' during key presses.

Fun for me to play , if it educates anyone, great. He posted to the right group with s.e.d.

Rich Grise wrote:

Nah. I won't argue with the general sentiment, but your arithmetic is off. Last time he gave a count, JT had 65 of us whitelisted.

G-Force Platinum from soundspectrum.com

Best audio stimulated light show to date.

Accepts external sources too!

Thanks a lot for the great response. Especially Jan for the circuit. As deduced from the evidence, I am a newbie. Dont have much practice but do surely know which end of the soldering iron to hold. Need the info to help somebody else implement it. However, didnt quite understand all the text symbols on the circuit. However, thanks for it, I will work it out. Thanks again, Nitin

This can be one and made into a cool product for hearing impaired telegraph instruction!

Marc