Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: razvanc_roro on April 29, 2007, 11:06:16 AM

Title: 50$ robot photoresistor
Post by: razvanc_roro on April 29, 2007, 11:06:16 AM

Can someone tell me what value is the resistor from the photoresistor used for the 50$ robot?
            340ohm resistor
OR
            1.62Kohm resistor

Thank you!

Title: Re: 50$ robot photoresistor
Post by: TravelingPencil on April 29, 2007, 12:35:46 PM

when i built the 50$ robot i used a random one from the assortment that i got at radio shack.

Title: Re: 50$ robot photoresistor
Post by: ed1380 on April 29, 2007, 02:44:57 PM

the 1.62k.
 you could have easily found out, by using the color code guide and the pics.

Title: Re: 50$ robot photoresistor
Post by: iCopyright_Everything on July 20, 2007, 01:03:49 AM

Hi guys,

Firstly, DO forgive me if by any chance I have duplicated a question here but I have searched the forum for this and come a-cropper...

I am in the UK & totally new to Robotics. For the $50 robot, I CANNOT order from Radio Shack (US only)

So what I need to know please is the properties of a good photoresistor to use for the $50 bot. Let me copy n paste what Ive found for it in british websites (light dependent resistors -- bloody british electronics companies dones even seem to HAVE the WORD Photoresistor in their lexicon!)

"
CHARTLAND

Order Code: 7482280

Manufacturer Part No: N5AC501085

RoHS :
Description

    * Light Dependant Resistor
    * Resistor element type:Light Dependent
    * Wavelength, spectral response peak:650nm
    * Series:NG
    * Resistance, @ lux A:100kR
    * Voltage rating, DC:100V
    * Case style:Radial
    * Depth, external:4.6mm
    * Diameter, lead:0.5mm
    * Length / Height, external:3.2mm
    * Length, lead:34mm
    * Power dissipation:50mW
    * Resistance, @ lux A max:100kR
    * Resistance, @ lux A min:50kR
    * Resistance, dark:5MR
    * Temp, op. max:60?C
    * Temp, op. min:-30?C
    * Wavelength, peak:550nm
    * Width, external:5.3mm
"

-------end of quote------

Is this appropriate?

PLEASE advise me ASAP as Ive ordered all the other stuff. Thanks!

Title: Re: 50$ robot photoresistor
Post by: Admin on July 21, 2007, 06:26:00 AM

Quote

So what I need to know please is the properties of a good photoresistor to use for the $50 bot.

As far as the $50 robot is concerned, if it looks similar to the one in the pictures, it will work fine for what you want.

There are only two concerns with any photoresistor:
1) response time - dependent on size and quality of the photoresistor
2) change in resistance wrt light absorbed

A browse at the datasheet should be able to tell you if it is acceptable.

Looking at your posted specs, that photoresistor looks acceptable to me.