Solar seeker: In this project we design a solar seeker to follow a sun. solar seeker follow the sun and if the sensor attach on the sensor a sense a sun then solar seeker is stop automatically. Now after some time sun move from its position, then again seeker sensor sense the light and move the motor very slowly. If the sensor sense the signal then automatically stop the seeker . Movement of the seeker is restricted from left to right for limited area. To control the left and right limit of the sensor we use reed sensor for this purpose. Reed sensor is a magnetically [pic]
For sensing the sun light we mount the photo sensor on the top of the solar seeker. Photo sensor sense the light and provide to the motor control circuit. If the light is sufficient then Photodetecter provide a signal to the microcontroller and microcontroller stop the motor at this position. [pic] In this project we use two LDR as a photo sensor. One LDR monitor the light and provide to the controller for stop the motor and second LDR sense a day or night logic. If the dark ness is there then controller stop the seeker for searching a light. Now seeker search a light in the day light only.
If the darkness is there or in the night then seeker stop the seeker for movement. To control the intensity of the LDR we use op-amp as a comparator. In this project we mount a solar cell on the solar seeker to get a voltage from the sun. when solar cell is under the sun then solar cell provide a voltage. We get this voltage and charge the chargeable battery. So what we are getting from the solar cell is display by the voltage level indicator circuit. With the help of this voltage level monitor circuit we monitor the voltage level with op-amp as a comparator ( LM 339) and display the voltage content by l. . d monitor circuit. c[pic] In this portion of circuit diagram we show the ldr sensing with op-amp as a comparator circuit. Here we use LM 358 as comparator circuit. LM 358 is further connected to the microcontroller. LM 358 is a dual op-amp package. Out of this one opamp is connected with the one LDR and second op-amp is connected with the second op-amp circuit. Both op-amp is work as a comparator [pic] In this OP-AMP, pin no 1 and pin no 7 is the output pins for both the op-amp amplifier. Pin no 2,3 and pin no 5,6 is a input pins of the op-amp circuit.
Pin no 4 is connected to the ground pin and pin no 8 is connected to the positive supply. In this circuit we use two ldr circuit , one is connected to the pin no 2 and second is connected to the pin no 6. reference level is set by the pin no 3 and 5 of the IC. On this pin we connect a variable resistor to set the reference level of the light. When light on the ldr is much more and above the set value of the reference value then op-amp provide a negative output to controller for sensing. Microcontroller when gets a active low input on pins then controller provide a action and stop the motor for movement.
Solar cell output is also connected to the opamp amplifier. Here in this portion of comparator we show the level of solar cell with the help of four l. e. d. All these l. e. d’s are connected with op-amp lm 339. LM 339 op-amp provide its output in four stage . [pic] In this circuit we monitor the battery level by set reference . we monitor the battery level in four step. If the battery is fully charge then all the l. e. d’s are on. All the l. e. d’s are on if the battery level is on 6 volt. If the battery level is down to . 5 volt then one l. e. d is off. So on every . 5 volt drop one l. e. d is off.