Inverter Diagram:

The Q1 and Q2 used generate square wave. Q5-Q8 amplify the signal and the transformer to increase the AC/square wave current from 12VAC to 220V AC 50HZ.

Inverter PCB layout:

The following image is the bottom/copper PCB layout and to layout for the components placement. You may use universal PCB veroboard to make it easier.

Components List:

The above inverter circuit converts 12VDC to 220VAC with power of about 50W. To circuit consists of the oscillator around the IC1, a divider IC2, an unstable polydoniti IC3, which gives the output of a symmetrical rectangular signal frequency 50HZ, followed by a buffer stage with Fet Q1-2, the driver stage and Q3-4 the power stage Q4-5, power transistors Q5-6, should be placed on a heatsink .. diodes Zener D2-3 protect the power transistors from voltage spikes produced by the transformer T1.

The transformer T1 are a simple power transformer with a medium shot, which is connected to the contacts of CO1. To use the wish, o T1, is placed upside down, with the secondary winding be used as primary, with the receiving means being connected to the positive battery voltage is 12V and the two other contacts are connected to the emitters of Q5-6, the connected to earth potential alternately, depending on the rate set by the outputs 10 and 11 of IC3. In this manner while flowing in the primary alternating current generated in the secondary alternating rectangular voltage 220V.

Using crystal oscillator ensures very good reference frequency 50HZ, and use a common crystal (CR1). For greater accuracy in parallel with C1, a variable capacitor CCH ensuring the adjustment of the frequency, in order to obtain the point P1 frequency 204.8 KIZ. It is evident that the output voltage at no-load is higher than the voltage under load. Also, the output voltage depends on the battery voltage. Thus for 14V battery voltage, the output voltage is increased by 10%, compared with the battery output voltage to 12V. If the converter works in load power 40 until 60W, then it can be used 2CH9V transformer. Various output values ??for battery voltage 12V transformer and 2CH10V.

50W Inverter 12VDC to 220VAC PCB Design:

50W Inverter 12VDC to 220VAC Component Placement:

circuit source

Basic Inverter Components list:

Notes:

1. Q1 and Q2, as well as T1, determine how much wattage the inverter can supply. With Q1,Q2=2N3055 and T1= 15 A, the inverter can supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power.

2. The easiest and least expensive way to get a large T1 is to re-wind an old microwave transformer. These transformers are rated at about 1KW and are perfect. Go to a local TV repair shop and dig through the dumpster until you get the largest microwave you can find. The bigger the microwave the bigger transformer. Remove the transformer, being careful not to touch the large high voltage capacitor that might still be charged. If you want, you can test the transformer, but they are usually still good. Now, remove the old 2000 V secondary, being careful not to damage the primary. Leave the primary in tact. Now, wind on 12 turns of wire, twist a loop (center tap), and wind on 12 more turns. The guage of the wire will depend on how much current you plan to have the transformer supply. Enamel covered magnet wire works great for this. Now secure the windings with tape. Thats all there is to it. Remember to use high current transistors for Q1 and Q2. The 2N3055’s in the parts list can only handle 15 amps each.

3. Remember, when operating at high wattages, this circuit draws huge amounts of current. Don’t let your battery go dead :-).

4. Since this basic inverter project produces 120 VAC, you must include a fuse and build the project in a case.

5. You must use tantalum capacitors for C1 and C2. Regular electrolytics will overheat and explode. And yes, 68uF is the correct value. There are no substitutions.

6. This circuit can be tricky to get going. Differences in transformers, transistors, parts substitutions or anything else not on this page may cause it to not function.

This is a basic and very simple low power inverter to convert 12V DC to 120V AC. How much power this simple inverter can handle the load depends the transformer current value and transistors you use for Q1 and Q2.

Inverter 12V DC to 120V AC Component List:
C1, C2 : 68 uf, 25 V Tantalum Capacitor
R1, R2 : 10 Ohm, 5 Watt Resistor
R3, R4 : 180 Ohm, 1 Watt Resistor
D1, D2 : HEP 154 Silicon Diode
Q1, Q2 : 2N3055 NPN Transistor (see “Notes”)
T1 : 24V, Center Tapped Transformer
Misc:
Wire, Case, Receptacle (for output)
Fuses, Heatsinks, etc.

Note: Don’t try to run inductive loads (motors) using this inverter.
More explanation about how its work and the component list about this simple power inverter, visit this page

Circuit Notes:

• A 12 V car battery can be used as the 12V source.
• Use the POT R1 to set the output frequency to 50Hz.
• For the transformer get a 12-0-12 V, 10A step down transformer. But here the 12-0-12 V winding will be the primary and 220V winding will be the secondary.
• If you could not get a 10A rated transformer , don”t worry a 5A one will be just enough. But the allowed out put power will be reduced to 60W.
• Use a 10 A fuse in series with the battery as shown in circuit.
• Mount the IC on a IC holder.
• Remember, this circuit is nothing when compared to advanced PWM inverters.This is a low cost circuit meant for low scale applications.

More explanation about this inverter circuit, please visit this page