Re: Light sensor circuit 0-5 volt output help required

["Frank Mc Alinden" <frankmc@xxxxxxxxxxxxxxxx>]

Hi Jason

The op amp i believe is being used as a comparator and not an amp....So the
output will switch once the threshold is reached....

> I want to use the sensor as a Dusk to dawn sensor ideal for example
> on a web brick / barionet. Having an analogue signal would allow
> different actions dependant on various levels.

Maybe connect the  LDR in series with a resistor    connect the ends to the
5v  supply of your web brick ....and then connect the centre position to
the
analogue inpt...Some experimentation required for the  correct resistor
value.....

HTH
Frank



----- Original Message -----
From: "ukhauk" <jasonstarkie@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Monday, April 10, 2006 6:58 PM
Subject: [ukha_d] Light sensor circuit 0-5 volt output help required


>I am trying to construct a light sensor circuit with an analogue
> output 0-5 Volt DC. Supply voltage around 12 volts
>
> I have been trying to adapt maplins MK125 Light Sensitive Switch
>
> http://www.maplin.co.uk
>
> The MK125 uses an op amp to compare a setpoint voltage with the
> voltage across a light sensor. Can I limit the output voltage on the
> op amp using feedback ?
>
> Or am I on the wrong track, has anyone come across such a circuit.
>
> I want to use the sensor as a Dusk to dawn sensor ideal for example
> on a web brick / barionet. Having an analogue signal would allow
> different actions dependant on various levels.
>
> any help or suggestions appreciated I have spent days on google
> without succsess.
>
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>
> Yahoo! Groups Links
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