Accesorizing Solar collection

[tedstruk]

My solar panel is 50v in full sun.
My controller charger is only 40v.

I need to accesorize the extra volts with a specialized voltage control, using a sign that says ---!!!!
"Teddys Solar Greenhouse"

Is it possible to power a lighted sign with raw solar power?

or do I need to put a rechargable 10v battery pack on it, isolate the charger at 10v from the solar controller

and then isolate the10v pack from the 12v system?

kind of hokey if you ask me.

 

[dave9]

Reconfigure the solar array to produce 25V at double current. Run through charge controller to 12V system. You're on your own making the sign.

 

[davenn]

Is it possible to power a lighted sign with raw solar power?

what lamps are used in the sign ? LEDs or filament lamps ( filament lamps don't need a well regulated voltage,
just a voltage that somewhere close to their ratings.

My solar panel is 50v in full sun.
My controller charger is only 40v.

and I would assume that is the open circuit/no load voltage as that is the way they are usually listed

once you put a load on it, it's voltage will drop probably at least 10V

to check that, you could put a pair of 24V ~ 40W truck headlight globes in series across the output of the panel and measure the voltage

 

[tedstruk]

can't reconfigure... I am a novice and it already looks like a christmas tree. So no reconfig, must be an electronics fix. So I think divider is that only way..

 

[tedstruk]

can't reconfigure... I am a novice and it already looks like a christmas tree. So no reconfig, must be an electronics fix. So I think divider is that only way.. I gota question about this schematic. My changes are in red..

 

[Harald Kapp]

First you need to check the output voltage of the panel under load (cf. Dave's post #3).

The circuit in your post #5 (taken from this website) is good for when the solar panel's output voltage is only slightly higher than the battery voltage (dropout voltage 1.25 V). If your panel's output voltage is much higher, this regulator will dissipate lots of power in the form of waste heat. In that case better use a switch mode charge controller. For optimum performance use an MPPT charge controller.

Want to build one yourself?

 

[tedstruk]

THIS IS DIY remember!
Wheres the gate drain and source on the original schematic? Did I get it right?
The schematic only had 1, 2, and 3, on the FETs contacts, and the Qfets emitter arrow was backwards...
Wheres the gate drain and source on the QFET? Did I get it right?
if you look at my schematic changes, the original numbers were covered by my edit...
eg.(as was) gate was 1 - drain was 2 - source was 3

 

[Harald Kapp]

Wheres the gate drain and source on the original schematic? Did I get it right?

yup

the Qfets emitter arrow was backwards.

The FQP27P06 is a P-MOSFET (QFET is the trade name by Fairchild). The symbol as shown in your post is correct. The arrow in the original schematic is not backwards. The original schematic uses a different type of symbol for the MOSFET, but is correct.