A question for electronics wizards

[Robin GrahamParticipant @robingraham42208]

[Robin GrahamParticipant @robingraham42208]

Well, it's Panto time again. Oh yes it is I'm afraid…

This year I have been asked to make a stone idol with eyes that flash in time with Robinson Crusoe's speech. Stone idol is no problem of course, any fule can do that, but I'm a bit stumped by the flashing eyes. What I want is to wire a mic to the idol so Crusoe can speak into it and the eyes flash – could be LEDs or torch bulbs.

Can anyone point me in the direction of a circuit (or a ready made device) which would do that? I've had a look on internet but no luck so far – probably I don't know the right search terms.

Robin

Edited By Robin Graham on 13/10/2018 23:35:42

[Grindstone CowboyParticipant @grindstonecowboy]

I think this (or something similar) will do what you need – **LINK**

Or search for "sound to light circuit"

Hope this helps,

Rob

[BazyleParticipant @bazyle]

In the end it might be easiest to go low tech and have a stage hand with a loose wire tapping it on a battery. Try that and see if it looks good enough.
The next thing is just try putting a LED across a loudspeaker and see if it flashes.

About 45 years ago I made a 3 channel sound to light system. I wonder where it is and if it still works.

[I.M. OUTAHEREParticipant @i-m-outahere]

You could use a vox unit ( voice operated switch ) to activate a simple light flasher made from a 555 timer or an arduino but one problem may be any noise from the audience could activate it . I would use a cheap remote control switch unit that can be activated by someone back stage at the appropriate time this would power up a simple light flasher either made with a 555 timer or an arduino .

[JasonBModerator @jasonb]

You can buy an LED driver quite cheaply that will drive RGB LEDs to music. I have fitted them for a couple of clients as soft lighting in bathrooms so you don't have to put a bright light on if you get up in the night. Their kids like the music option as they will flash and change colour according to sound not just music.

The ZAP one shown here, (just select "beat" ) is what I have used but there are quite a few options depending if you want phone control etc

[John HaineParticipant @johnhaine32865]

One bridge rectifier with the ac input connected to the speaker output of an amplifier, smoothing cap on the dc side, drive the leds through a suitable resistor. Robert is your father's brother.

[Robin GrahamParticipant @robingraham42208]

Thanks for suggestions, which I've followed up. I'm now much better informed.

Kids who want sound modulated bathroom lighting eh? I was happy with half a capful of Matey and a candle lit under the tub in winter, what's the world coming to etc etc.

Bazyle's low-tech solution is probably the way to go – robs me of the chance to learn some electronics, but frees time to figure out to make fishes with moving mouths. Arduino or a couple of pegs and bit of string? Tough choice!

Robin.

[Robin GrahamParticipant @robingraham42208]

Well, the low tech solution got past the H&S people – I'm no longer allowed to take mains voltage to stage props, but a 12V lead-acid battery is fine. What could possibly go wrong with 12V?

I've now put a fuse in, but the absence wasn't noticed.

Robin

 

Edited By Robin Graham on 26/10/2018 00:43:56

[I.M. OUTAHEREParticipant @i-m-outahere]

It could emit hydrogen gas that can explode in the presence of a spark

On a more serious not that is why when jump starting a car you hook the negative to the chassis not the battery because the final connection usually causes a spark whick you don’t want right on top of the battery ( that is for neg earth cars so if pos earth the positive goes to the chassis ) .

I don’t think you will have any problems with this set up , you could get away with a small sealed lead acid battery but i would make up a small contactor unit out of some sheet brass so you can tap on it like a morse code key or you could use a momentary push button swtch to do the same .

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