That would be interesting.  The 555 is a simple circuit, I just can't 
solder that little stuff.
73
Butch
WA0VJR
Node 3148
Wallace, ks.


On Mon, 13 Apr 2015, Alan R. Downing wrote:

> Hello Butch.  A friend of mine made me an LED detector that emits a tone
> when the nose of the device is placed over an LED or any light source for
> that matter.  It runs on a 9V battery, and it works slick as snot.  I can
> attempt to get the schematic, assuming that he actually drew one.  I believe
> that all of the parts combined came to about $10.
>
> Alan - N7MIT
>
>
> Alan R. Downing
> Phoenix, AZ
>
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Butch Bussen
> Sent: Monday, April 13, 2015 2:07 PM
> To: [log in to unmask]
> Subject: Re: light detector
>
> Unfortunately I'm no good at soldering stuff like that.  Some one else
> mentioned a circuit using transisters.  I'd like to have that diagram,
> as I might be able to do that, although the only transister audio
> oscilators I recall used a center tapped audio transformer.
> 73
> Butch
> WA0VJR
> Node 3148
> Wallace, ks.
>
>
> On Tue, 14
> Apr 2015, Dave Allen wrote:
>
>> Hi Butch!
>>
>> Many thanks for the design and description.
>>
>> A couple years ago, I contacted the Blind Foundation's equipment shop and
>> told them I wanted to buy a light probe. They had no idea what I was
> talking
>> about. I sourced one overseas, as that's what local incompetence generally
>> promotes, hi hi.
>>
>> 73,
>> Dave
>>
>>
>
>