There is a 9.1k resistor in series with a 100K that forms the reference voltage for the
East and West comparators. The ref voltage is about 1.18v when using 13.7Vcc.
The manual says that 9.1k can be replaced with a 10k pot (10 turn).
I don't have a 10 turn, but I did find a 13k trim pot that I will install tomorrow.
During bench testing, the only way I could get the test motor
to switch rotational direction, was to aim the sensor unit at the VERY bright sunlight.
I was actually it holding outside the window (on a cold day) just to get it working right.
One thing that's worrisome right now, it's pitch black out there and the tracker is just sitting dead.
It didn't return to the home posistion (max east).
During testing today, I put a black cover over the sensors and it just sat.
So, I think maybe something else might be wrong.
Last month, Blocking all light worked okay on the bench. The test motor took off for east.
The reference voltage might be the key, since today both the E & W
relays were energized (by the E & W comparators).
A close look at the circuit, shows when both relays are on, there is no juice to the motor..
If it's not the ref voltage, it can only be the IC (LM399)..
~~~
Anyways, when I get this thing tracking like it should, I plan to purchase some real PV for it.
Maybe a couple of 120 watt panels!
