How to Build an Inverter part 2 of 2

Circuit Description

To better understand how to build an inverter, it is important to learn how the circuit functions through nthe following steps:

• Gates N1 and N2 of IC 4049 are configured as an oscillator. It performs the primary function of supplying square waves to the inverter section.

• Gates N3... N6 are used as buffers so that the circuit is not load dependant.

• Alternating voltage from the buffer stage is applied to the base of the current amplifier transistors T1 and T2. These transistors conduct in accordance with the applied alternating voltage and amplifies it to the base of the output transistors T3 and T4.

• These output power transistors oscillate at a full swing, delivering the entire battery voltage into the each half of the secondary winding alternately.

• This secondary voltage is induced in the primary winding of the transformer and is stepped-up into a powerful 230 volts (AC). This voltage is used to power the output load.

How to Build an Inverter part 1 of 2

Charger: During power backups when the battery gets discharged to a considerable level, the charger section is used to charge the battery once the AC mains is restored.

How to Build an Inverter

 To clearly understand how to build an inverter, let’s go through the following simple construction details:

• As per the circuit schematic first complete the assembly of the oscillator section consisting of the smaller parts and the IC. It is best done by interconnecting the component leads itself and soldering the joints.

• Next fit the power transistors into the appropriately drilled aluminum heat sinks. These are made by cutting an aluminum sheet into the given sizes and bending them at the edges so that it can be clamped.

 

• Do not fit the transistors directly on to the heat sinks. Use mica isolation kit to avoid direct contact and short circuiting of the transistors with each other and the ground.

• Clamp the heat sink assembly to the base of a well ventilated, sturdy, thick gauge metallic enclosure.

• Also fix the power transformer beside the heat sinks using nuts and bolts.

• Now connect the appropriate points of the assembled circuit board to the power transistors on the heat sinks.

 inally join the power transistor’s outputs to the secondary winding of the power transformer.

• Finish the construction by fitting and interconnecting the external electrical “fittings” like fuses, sockets, switches, mains cord and the battery inputs.

• An optional separate power supply circuit using a 12V/3Amp. transformer may be added inside to charge the battery whenever required (see diagram).