hello everyone! I'm currently working on a project where I aim to utilize a photovoltaic (PV) panel to power a laptop. However, I'm facing some challenges when it comes to designing a circuit to regulate the output voltage from the PV panel. I'm reaching out to this knowledgeable community in the hopes of finding some guidance and assistance.
- It's about only daytime powering, using solar light, not a batery
- so a solar panner could supply up to 18V DC, variavle voltage, while for laptop 19V constant DC are required

 

Welcome to AAC.

Without more information my answer is to get an MPPT (Maximum Power Point Tracking) solar charge controller and a suitable battery. You can either buy the pieces or purchase one of the many complete systems based on lithium ion batteries (best would be LiFePO4).

 

Without any information the best you get is a guess. Many laptop computers use an external DC supply of about 19 volts and often around 3 amps capability. So to provide that the array must deliver at least 57 watts. Now you have a starting point.

 

The Solar-Panel is for charging a Battery only,
and it must deliver Power substantially in excess of the requirements of the Computer.
A Laptop usually requires around ~60-Watts,
the Solar-Panel should be capable of around ~twice that amount
of Power to make this arrangement work somewhat reliably.

"No Batteries" at all,
means the Computer crashes when a cloud blocks the Sun.

The Battery built-into the Laptop,
may prevent crashing caused by lack of Output from the Solar-Panel,
but, the Charging-Circuitry in the Laptop "may" do some strange things
when the external-Charging-Power fluctuates wildly.
.
.
.

 

If the panel output voltage ***always*** will be less than 19 V, then a non-isolated boost converter will give you a regulated 19 V source for the laptop.

But -

Again, the panel output must be less than the 19 V requirement. If it goes above 19 V, some converters will pass this straight through to the output. You could wind up with 24 V going to the laptop.

Also, the boost converter will require more input current than the laptop. Boost circuits are relatively inefficient, plus there is that whole conservation of energy thing. For example, using nice round numbers, if a theoretically perfect, 100% efficient boost converter boost a 12 V input to an 18 V output, then for every amp the load draws at 18 V, the converter draws 1.5 A at its input. A switching power supply converter can be thought of as a DC transformer: if the output voltage goes up, the output current goes down.

ak

 

One approach often used is to have your panel drive an inverter to make regulated AC power and then simply plug your typical laptop power brick into the inverter. Of course this introduces some inefficiency but it's SO much easier to set up, is more versatile for future projects, and all you need is slightly more panel capacity to cover the larger losses.

 

hello everyone! I'm currently working on a project where I aim to utilize a photovoltaic (PV) panel to power a laptop. However, I'm facing some challenges when it comes to designing a circuit to regulate the output voltage from the PV panel. I'm reaching out to this knowledgeable community in the hopes of finding some guidance and assistance.
- It's about only daytime powering, using solar light, not a batery
- so a solar panner could supply up to 18V DC, variavle voltage, while for laptop 19V constant DC are required

I think you will need some type of storage to make this practical. If not a battery, how about 'super caps'?

 

Maybe two panels in series so you have 30 to 40 volts? Big capacitor (50V 10,000 uF?) for smoothing; buck converter to get 19V.

 

There are already published circuits designed to provide a constant 13 volts to radio equipment as the supply battery drops to ten, or even nine volts. One of those could be modified to provide a constant 19 volts.