DD or green always on if B1 is above 12V & R 28 is set to cut off battery if B1 falls below 11.8 V to 12V.

 

DD still on right now, voltage measure at 11.94V. LED circuit did not light up since afternoon till now (1:26AM here). Hopefully tomorrow have some nice sunlight to test it out.

 

Tested today but no luck, sunlight is very weak, solar panel OC about 20V but current only about 110mA. LED circuit light up but very weak, measure the voltage going to LED circuit only range between 6.5 to 7.5V.

 

Then battery should have kicked in.

 

I've tried to make a list of different Vs & what controls them.
A 2.5 V, SP1, TB1-1, transition from day to night, non adjustable, set by U3-2.
B 4 V to 9 V, TB1-1, allow battery operation under low sun conditions in daylight; adj. R 20
C 10.8 V +_, record, TB3-1,normal day time operation, BR2 set to 10 V at D1-1.
D 10 V See C above,
E 9.5 V, D2-1, low SP1 output, below about 10 V, allowing B1 to supply power, adj. BR1.
F 13.8 V, BBR1, TB7-1, max charge V, set BBR1.
G 11.8 V to 12 V, B1-1, low battery cut out, adj. R 28.
H 12.5 V to 12.8 V, B1-1, re connect battery, set
by R 30, estimated fixed value.
I 10.2 V to 10.5 V, TB3-1, a V just below normal TB3-1 reading to stop charging if SP1 cannot supply both LEDs & charging, adj. R 23.

 

Okay thanks Benard, I will try to simulate with 2 battery and set the settings then try on solar panel. I just cannot understand why solar panel have OC 20V and only output about 7v on TB3-1.

 

jenovauh, when you see an abnormal V reading, see what conditions may contribute to reading. TB3-1 measures 7 V & should be about 10.7 V; can SP supply up to 300 mA into a load?; how is BR2 set?; is there excessive load on TB3-1? With SP disconnected from ckt, measure output with various loads; or see what load is required to bring SP V down to 15 V, should be around 50 Ω. 1/2 W resitror,s OK if put in a glass of water & short measuring times. Re connect SP, remove any other loads except for BR2, like BBR1 & D1-2. Set BR2 for 10.7 V, can be later trimmed to give 10 V at D1-1 when every thing is operating normally.

 

I just check my whole circuit again and found out I forget to connect Q3-8 to TB5-1. Now that the circuit connection is correct. I am using a 12V battery to act as solar panel. I can see that DA and DD are lighted up. Can I know what does the DA, DC and DD indicate when they are lighted up?

 

DA on; Daylight, if low SP output, battery backup available.
DC on; SP is charging battery.
DD on; Battery V is normal.

 

Okay thank Benard, I will check that later when I got home. At work now and we are having our Chinese New Year tomorrow. I will update again soon.

 

Just an update, I think my solar panel didn't output enough current and the buck doesn't seem to work well. The solar panel output about 20.5v and 185mA, the LED circuit is only getting about 7.5v and barely light up. I guess need to parallel another set of solar panel to output more current. Will try to fix that and try again in a few day. Still having our Lunar new year over here.

 

SP output is almost 3 W, enough for LED's @ 5 W peak & 1/2 W average, with a little left over for charging. O-scope readings might be more meaningfull. For testing it may be helpfull to substitutea 100 Ω resistor for the LED bank, with a single LED & 430 Ω R, as a monitor.

 

okay I will try to use the single LED method for testing this coming weekend. But I am still quite surprise why 20.5V with 185mA could not power up the LED circuit. Maybe I did not assemble properly in the circuit.

 

Remember that the LED's are operating at 25% duty cycle & will appear dim.

 

I fully understand that it is running at 25% duty cycle. I try using direct 12v battery to the LED circuit and separately from the solar panel to charging circuit to LED circuit. It is way too dim when I compare them.

 

Do you have 10 V at D1-1 ?

 

Hi tracecom and Benard, so sorry for the long delay and I am back to Singapore from China on project. Basically could not access to the forum from China. Anyway I will continue the circuit when I have settled down.

 

Just an update I had reassembled the LED circuit and test the frequency. Somehow the given schematic frequency is pretty much off from 720Hz, it is around 900+Hz.

Anyway I manage to change the resistor value for R1 to 20K ohm and R2 to 172K ohm to get around 733Hz on scope. But it is normal that it will show about half of the frequency once in awhile through the scope? The duty cycle is pretty low.

I will work on the charging circuit later tonight again to refresh my memory.

 

CMOS (Complementary Metal Oxide Semiconductor) -- runs down to ~3VDC. Valid logic high is > 73% of VCC and logic low < 26% of VCC.

Leds have varying forward voltage drops. Red ~1.8V. Green ~2.1V. Blue ~3V. Throw a capacitor on the output for a bit more punch?

Yeah throw a large electrolytic on the output for a bit more punch.

 

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