how to build an inverter

[yommie quincy]

pls i have been given a project to build an inverter, i need someone to teach me how to build it and to tell me things to buy

 

[audioguru]

Your teacher is paid to teach you. We are not paid to teach kids.

Simply buy an inverter, take it apart then put it back together in your own enclosure.

 

[nkukard]

If its a project to build an inverter by yourself asking someone to do the work for you is not going to teach you how to do it, use google, read up on the theory and have fun ..... shouldn't anyone who is doing electronics as a course actually want to learn from it ?? asking for the easy way out is NOT learning

 

[gary350]

This is what you need. I built this myself about 5 years ago. It will run a 100 watt light bulb. I used a 120 VAC to 12 VAC transformer hooked up backwards. My output was not 120 VAC it was more line 100 volts. I had to rewind the transformer secondary winding to make it produce 120 VAC. Be sure to use a good heat sink on the 2N3055 transistors I use a sheet of 1/4 inch aluminm plate.

12V to 120V Inverter

 

[audioguru]

This is what you need. I built this myself about 5 years ago. It will run a 100 watt light bulb.

The garbage circuit does not work.
A few years ago its capacitors had backwards polarity which caused them to blow up. They still blow up. Look at the forum about it on that website.
It still has the emitter-base junctions of the transistors with avalanche breakdown so most of the current from one transistor breaks down the other transistor (the emitter-base breakdown voltage rating is only 7V and the capacitors try to feed them 23V at a high current).
There is no where near enough base current for the transistors to conduct enough current for an inverter. The 180 ohm base resistors feed a base current of only 71mA so the output current from each transistor is only 0.71A. Then the transistors provide output power of only 0.71A x 12.8V= 9W most which breaks down the emitter-base junctions and blows up the capacitors.

 

[gary350]

The garbage circuit does not work.
A few years ago its capacitors had backwards polarity which caused them to blow up. They still blow up. Look at the forum about it on that website.
It still has the emitter-base junctions of the transistors with avalanche breakdown so most of the current from one transistor breaks down the other transistor (the emitter-base breakdown voltage rating is only 7V and the capacitors try to feed them 23V at a high current).
There is no where near enough base current for the transistors to conduct enough current for an inverter. The 180 ohm base resistors feed a base current of only 71mA so the output current from each transistor is only 0.71A. Then the transistors provide output power of only 0.71A x 12.8V= 9W most which breaks down the emitter-base junctions and blows up the capacitors.

OK....I found my circuit and it is different. At first glance it looked the same but it is NOT.

180 ohm 1 watt resistor is the same.

My circuit does NOT have the Diodes D1 and D2.

My circuit does NOT have R1 and R2 resistors.

2N3055 transistors are the same.

Transformer is 10 to 1 ratio 120 vac primary 12 volt secondary with Center Tap 350 watts.

You need a good heat sink for each transistor.

68 uf or MFD I used motor run capacitors not electronic capacitors. You can use a 70 mfd or a 40 and 25 mfd in parallel. You only need them rated at about 25 volts but there is no such thing the lowest voltage I can find is 110 volts AC rating.

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I can run a 100 watt light bulb NO Problem at all. It works but it is no where near as good as a $25 DC to AC chinese made 400 watt inverter.

 

[audioguru]

OK....I found my circuit and it is different. At first glance it looked the same but it is NOT.

The parts you removed prevent the transistors from blowing up from the very high voltage spike produced by the inductance of the transformer when a transistor turns off.

There are many circuits on the internet that do not work.
Most Instructables are designed by people who know nothing about electronics.

The output of this awful "inverter" is a square-wave so a multimeter cannot measure it correctly.