Does this work?

Using Arduino General Electronics
1

Hello,

Does this work as i hope?

What happens, if the main supply fails?
Does the battery or the solar module damage the power supply?
Or is it safe?

Thanks,
Alex

solar01.png

2

Is the solar module a source of power?
I can see you over charging the battery and yes current will be put through the supplies in case of mains failure.
Sprinkle some diodes arround to prevent back feeding stuff.

3

What means "Vo = 24 V" on the right?

4

Thank you.

V0 ist the output voltage of the pv solar module without load.

@Grumpy_Mike
So i will use diodes.
I have seen a replacment circuit with a MOSFET transistor before,
but can't remember where and what's its name?

Alex

5

You mean something like this, it is from the new B+ Raspberry Pi.

raspberry_pi_modelb_powerin.png

6

You need diodes bet ween the solar cell and battery and also the psu and battery if there is no internal one.
You also need a shunt regulator to prevent the solar call overcharging.

Psu needs to have a supply voltage less than the shunt regulator turn on point or it will see a short.

7

Boardburner2:
You need diodes bet ween the solar cell and battery and also the psu and battery if there is no internal one.
You also need a shunt regulator to prevent the solar call overcharging.

Psu needs to have a supply voltage less than the shunt regulator turn on point or it will see a short.

This also assumes the psu has propper charge control circuitry as well

Its not the best arrangement.

Here is an alternative

solar chargin circuit with mains supply
http://homemadecircuitsandschematics.blogspot.co.uk/2012/10/solar-panelac-mains-relay-changeover.html

8

@Grumpy_Mike

Yes, it was something like this circuit.

@Boardburner2
Thank you for the schematic, maybe i will try this.

Alex