Solar Inverter Circuit with Charger

This is a Solar Inverter Circuit with Charger.

It uses sun power to give AC light at home.

It charges battery from solar panel and make light with inverter.

This type of circuits are good for small home use or where there is no electricity.

Circuit Working:

Parts List:

When switch in solar mode solar panel connect to battery through emitter follower and s battery gets charged.

When switch changes to inverter mode then solar panel disconnects and now battery connect to inverter.

Inverter uses transformer and flip-flop transistors to change battery DC to AC.

Then transformer makes AC voltage bigger and we get AC power at output.

Formulas:

Below are some easy formulas for emitter follower circuit and these help to set transistor bias and check AC working.

DC Biasing:

Base Current (IB):

IB depend on transistor gain (β) and how circuit is connected the formula for these are:

IB = (VCC – VBE) / RBias

where:

• VCC is the power supply voltage
• VBE is the base to emitter voltage which is around 0.6V for silicon transistor
• RBias is the resistor connected to base from voltage like in voltage divider

Emitter Current (IE):

Transistor gain tell how base and emitter current are link.

Formula:

IE = (β + 1) × IB

here,

• β or hFE is transistor gain.

AC Characteristics:

Voltage Gain (Av):

Voltage gain in emitter follower is almost 1 and it can be from 0.8 to 0.999.

Av = 1 (approx)

Note:

These formulas give basic idea only and for more detail we can use small signal model.

How to Build:

To building a Solar Inverter Circuit with Charger follow the below mentioned steps for connections:

Solar Charger Connection:

• Connect solar panel positive wire to TIP35 base.
• Connect solar panel negative wire to ground.
• Connect TIP35 emitter to battery positive (+).
• Connect TIP35 collector back to solar panel positive.
• A 15V Zener diode connects to TIP35 base and other end of Zener connects to ground.
• Emitter follower output (+) connects to battery positive (+).
• Emitter follower output (–) connects to battery negative (–).
• Connect emitter follower output (+) also to one pole of SPDT switch.
• Other pole of SPDT switch connects to solar panel positive.
• Common terminal of SPDT switch connect to battery positive.

Inverter Circuit Connection:

• Use two 2N3055 transistors in cross-coupled way.
• First transistors collector connect to second transistors base and second collector to first base.
• Both emitters connects to battery negative (–).
• Primary winding of transformer connects to collectors of 2N3055.
• Secondary winding of transformer connects to load like fan, light, etc.
• SPDT switch common terminal connect to where collectors and transformer join.
• One SPDT pole connect to battery negative (–).
• Other pole connects to transformer negative end.

Testing:

Solar Charging Test:

• Put SPDT switch in solar charging mode.
• Be sure battery is charging and voltage is not too high.

Inverter Test:

• Put switch in inverter mode.
• Check AC output from transformer secondary.

Important Notes:

• Be careful and always follow safety steps.
• Do not let battery overcharge.
• Be sure components are good for power used.
• Add fuse and heat check for safe use.
• Keep wires and parts tight and clean to avoid short circuit.

Safety Tips:

• Use fuse to stop too much current.
• Use cut-off circuit to stop overcharging battery.
• Check temperature of transistor and transformer to stop overheating.
• Be sure all wires are tight with no loose or wrong connection.

Conclusion:

This Solar Inverter Circuit with Charger is just a simple guide.

But actual circuit may look different depending on parts we use and their power and voltage ratings.

Always check datasheet of each part to know correct values and limits.

If we do not know electronics well then better to ask help from someone who know or talk to a professional.

Also follow local safety rules and electrical laws to stay safe.

References:

Single Phase Solar inverter with smart Charge control

Inverter for the Solar Panel