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Electronics => Electronics => Topic started by: tipsy13 on February 20, 2008, 08:13:09 AM

Title: photo resistor as switch
Post by: tipsy13 on February 20, 2008, 08:13:09 AM
im currently making a project that will use a photoresistor sensor to act as a switch to drive a stepper motor.basically what my machine will do is the when sunlight hits the sensor,the stepper motor will move clockwise and when there is no sunlight the motor will move counter-clockwise. i will also use an mts 88.c microprocessor trainer and an I/O board 4 for this. but my main concern is how will i make the photoresistor act as a switch?

im a noob here and i cant seem to find any article about this anywhere..thanks alot guys..
Title: Re: photo resistor as switch
Post by: 555 timer chip guy on February 20, 2008, 01:15:59 PM
Try a transistor and a relay also I have a circuit if you would like it that outputs a pules.
Title: Re: photo resistor as switch
Post by: airman00 on February 20, 2008, 02:07:02 PM
comparator and photoresistor


search the forum for comparator , i have already explained it here to someone else
Title: Re: photo resistor as switch
Post by: tipsy13 on February 20, 2008, 07:18:29 PM
im kinda lost here..so i should use a comparator?cant i just hook it up to the mts 88.c and make the photoresistor send a pulse ?555timer guy,a circuit would really help me..tnx
Title: Re: photo resistor as switch
Post by: airman00 on February 20, 2008, 07:43:18 PM
read this post for info

http://www.societyofrobots.com/robotforum/index.php?topic=3147.0 (http://www.societyofrobots.com/robotforum/index.php?topic=3147.0)
Title: Re: photo resistor as switch
Post by: 555 timer chip guy on February 20, 2008, 09:51:12 PM
im kinda lost here..so i should use a comparator?cant i just hook it up to the mts 88.c and make the photoresistor send a pulse ?555timer guy,a circuit would really help me..tnx

Here is a circuit that uses a comparator. It will give you a plain digital signal 1 or 0. 0 for light hitting the sensor and 1 for darkness and the 10k pot determines the threshold.