Solar Tracker Problem

BobTPH

Joined Jun 5, 2013
11,516
The LDRs are both connected to pin 8. One is going to VCC and other to ground. That's correct according to my limited knowledge of how circuits work :D
Also I'm using 1K resistors intentionally.

And the circuit is on a tablet next to me.
Look at the schematic again. Is pin 8 the only pin the two LDRs should be connected to?

What about the two resistors? Are they connected to every pin the schematic shows connections to?

Once again: check every connection in the schematic to see if it is made in your breadboard.
 

ScottWang

Joined Aug 23, 2012
7,501
Long long time ago, maybe over 40 years, I had planned to do the same device, and I would like to use 4 LDRs to control the 4 directions of motor, but all the thoughts only in my mind ... :D

Edit:
Use 2 motors to adjust the 4 directions.
 

Aan.jpg

Joined Jul 29, 2015
5
https://www.st.com/resource/en/datasheet/cd00000134.pdf

1. What type of motor you used ? what is your motor voltage and power / current consumption ?
I saw from datasheet, if configured as a bridge the max power output can be 2000 mW at 9V power source, but it depend on the load impedance, the datasheet mentioned typical loudspeaker impedance : 4/8/16/32 Ohm, for motor you need to check voltage (max/min voltage) and current consumption.
2. Your configured this amplifier like standard voltage comparator op-amp , when LDR1 is bigger than +Vs/2 then out(3) will be +Vs and Out(1) will be 0, so motor will be turning CCW, when LDR2 is less than +Vs/2 then out(3) will be 0 and Out(1) will be +Vs, so motor will be turning CW
3. so , first, I suggest you to test the circuit without motor and measure :
- when LDR1 is covered, measure voltage at pin 6/8 if it will be higher than voltage at pin 6/8,
at this condition measure the voltage output polarity , pin 3 will be : +vs and pin 1 will be 0
- when LDR2 is covered, measure voltage at pin 6/8 if it will be lower than voltage at pin 6/8,
at this condition measure the voltage output polarity , pin 3 will be : 0 and pin 1 will be +vs
 

Thread Starter

BjorkElec

Joined Nov 28, 2024
37
Hi,

I've come to a conclusion that all those chips are not working. Shop owner told me they're Chinese. So maybe that means it has a different pinout??
Anyways
I finished the project by using a single L293D IC with a voltage divider for the LDRs.
It works flawlessly.
 
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