A 21 V SP would be a start. It's way past my bed time & I have a rotton cold, see you tomorrow.

 

A 21 V SP would be a start. It's way past my bed time & I have a rotton cold, see you tomorrow.

Sure I will configure one on this coming weekend. You have a good rest and let me know what to do next.

 

I had configured the 21V OC solar panel. whats next?

 

We can now replace BBR1 with a buck reg. also BBR2 if you have another buck.

 

Other than that do I need to replace anything as I think the circuit had included a lot of other resistors and LED for testing. I am not sure if I am able to do that kinda testing.

 

We can now replace BBR1 with a buck reg. also BBR2 if you have another buck.

I won't be able to make this change until I get more buck regulators from China.

 

tracecom, maybe you could use the buck that is subing for SP & use the FET electronic load as a variable V source but with a higher DC V supply. That is what I use inside. Keep BBR2 for now. I tested a 21 V SP & buck on a overcast day, shaddows just discernable, and noted that power was sufficinent to light LED's, but alas. if sun light was brought up slowley SP stayed in high current, low V range & could not make the jump to normal operating power point. In full bright sun this did not happen. Can we face adding a soft start ckt?
jenovauh, what is our new short ckt. current?

 

I could not even try out the solar panel for weeks. Everyday either raining or very cloudy with dark cloud in Singapore. Especially I only when I only have weekends to test and they are always raining heavily.

 

tracecom, maybe you could use the buck that is subing for SP & use the FET electronic load as a variable V source but with a higher DC V supply. That is what I use inside. Keep BBR2 for now. I tested a 21 V SP & buck on a overcast day, shaddows just discernable, and noted that power was sufficinent to light LED's, but alas. if sun light was brought up slowley SP stayed in high current, low V range & could not make the jump to normal operating power point. In full bright sun this did not happen. Can we face adding a soft start ckt?

My input voltage to the buck regulator simulating the solar panels is only 15V. I suppose I could rearrange the regulators as follows.

Use the boost buck (that used to be BBR1) to simulate the solar panels, and use the freed-up buck (that used to simulate the solar panels) in place of BBR1. Yes?

 

That should work.

 

That should work.

Okay, I have made that change to the schematic and saved it as a new document; a PDF is attached. What other changes are needed?

 

Adjust BR2 to give 10 V at D1-1, then lower SP V to where Green & Yellow are on, check D1-1 for 9.5 V. Start at night & let the sun come up & see what happens.

 

Adjust BR2 to give 10 V at D1-1, then lower SP V to where Green & Yellow are on, check D1-1 for 9.5 V. Start at night & let the sun come up & see what happens.

What should the output voltage of the solar panel be at the beginning of the test?

And I have to reconnect some things and eat lunch, so it will be a will before I post any results.

 

About 2.5 V, transition between night & day.

 

I have finished reassembling my breadboard lash-up. Everything is hooked up as shown in the attached schematic. I noticed that version A0 of the schematic did not include the voltage divider on U2 pin 5, so I added R17 and R32 to the schematic, and increased the Rev. level to A1. A PDF is attached.

After supper, I will try to do some testing.

 

Had something miswired last night, but I think I have it all straight today.

Set R100-2 to 19.99V (solar panel output.)
Disconnected R21-2 from Q4-1, set R21-2 at 14.00V. Reconnected R21-2 to Q4-1.
Disconnected D2-1 from D1-1, set D1-1 to 10.00V. Set D2-1 to 9.50V. Reconnected D2-1 to D1.1; junction voltage is 9.96V.

Battery is at 12.54V. DA lit, DC dim, DD lit, DE lit.

Began decreasing solar panel output from 19.99V. At R100-2 = 13.59V, D1-1 begins to fall. At R100-1 = 9.96V D1-1 = 8.91V and stops falling. DD is off.

At R100-1 = 2.5V, D1-1 drops from 8.91V to .983V. DA and DE are off.

Began increasing R100-1.

At R100-1 = 6.24V, D1-1 jumps to 8.91V. DA and DE come on.

As R100-1 passes 10.24V, D1-1 begins to climb.

At R100-1 = 14.0V, D1-1 reaches 9.95V and stops climbing. DC comes on dim, then after a few seconds is on bright.

Increased R100-1 to 19.99V. No further changes.



What is the meaning of life?

 

Nice measurments. All seem normal except DD, which should always be on if battery is above 12 V. Might be interesting to commect a V meter between D1-2 & D2-2, to see when B1 picks up & drops load.
Also you might set R100-2 to 15 V, approx. MPP, max. pwr. point, & let it run to see if battery reaches full charge.
Short test with SP, Buck & 30 ohm load,
about 330 mA from SP; then if insolation was decreased, B would drop out of regulation, but by adding a large cap, 22,000 [ slight over kill ] & momentarily breaking SP connection regulation was re established. Will save this feature for later use if necessary.

 

Nice measurments. All seem normal except DD, which should always be on if battery is above 12 V. Might be interesting to commect a V meter between D1-2 & D2-2, to see when B1 picks up & drops load.

The polarity switches as R100-2 passes through 10.57V.

Regarding DD, remember that I have to connect the battery repeatedly until DD lights fully. There is something flakey about it.

 

DD is not really flakey, it is that when B1 is connected to ckt. V is somewhere between disconnect V & re-connect V. Adding a startup cap, 4.7μF to 10μF, between B1-1 & U4.2-6 might allow DD to be on at startup, & have no other effect on operation. If B1 is temp. disconnected & replaced with " SP " variable V, battery drop & re-connect V's can be checked & or adjusted.

 

DD is not really flakey, it is that when B1 is connected to ckt. V is somewhere between disconnect V & re-connect V. Adding a startup cap, 4.7μF to 10μF, between B1-1 & U4.2-6 might allow DD to be on at startup, & have no other effect on operation.

A 10uF in parallel with R15 did the trick.

If B1 is temp. disconnected & replaced with " SP " variable V, battery drop & re-connect V's can be checked & or adjusted.

I'll have to think about where to make measurements (or you can tell me.)