CD 4047 inverter

[Oldsnake00]

Hi all
I bulid inverter from same circuit in picture and use tranformers doble output form below link. Why my curcuit generate output =110v at 50hz?

Tranformers = 220v to 9+9 v 3va
http://www.yhdc.com/en/product/465/

Circuit

 

[Bluejets]

240/6 = 40:1
240/12 = 20:1

 

[duke37]

What frequency did you use? If the frequency is too low, the transformer will saturate and give a low output.
The transformer is vey small and the output will drop significantly when a load is applied.

 

[Alec_t]

The lowest oscillation frequency your circuit will produce, according to a Spice simulation, is about 90Hz. There will be some shoot-through, so the FETs are likely to overheat. I think that poor little 3VA transformer will probably saturate, as duke says.

 

[Oldsnake00]

What frequency did you use? If the frequency is too low, the transformer will saturate and give a low output.
The transformer is vey small and the output will drop significantly when a load is applied.

Hi duke37 This use for dc cdi from below link.
https://www.electronicspoint.com/threads/dc-cdi-12-220-issue.275097/page-2#post-1661476

 

[duke37]

The link shows that there was considerable problems, did it ever work?

A capacitor discharge ignition needs about 300V on the primary to get 6kV on the secondary. Considerable power will be needed depending on the spark rate.

You could get a 6-0-6V 3A transformer running at 200Hz and voltage double the output if necessary.
An alternative is to wind your own transformer to suit. I have made one with a TV line output transformer core with one turn per volt, running at about 10kHz to generate 400V for a transmitter.

 

[Oldsnake00]

Please show your inverter from tv transformers.

 

[Oldsnake00]

Hi duke37 and all
I found below link from internet.
http://320volt.com/12v-220v-dc-dc-konverter/
I can use irfz44 drive it? how much value of resistor for drive irfz44?

 

[duke37]

When I was in hospital, I was 'tidied up' and I do not know where things are.
The ferrite TV transformer core is square shaped and the windings are put on one side. The advantage of this transformer is that it has an air gap made with a thin sheet of paper or plastic. As a result it can easily be dismantled. It should be re-assembled without the gap since the circuit is push-pull.

What resistor do you mean? There are timing resistors connected to the 555.
A 39pF timing capacitor will give a very high frequency which would not suit a transformer with iron laminations.

 

[Oldsnake00]

When I was in hospital, I was 'tidied up' and I do not know where things are.
The ferrite TV transformer core is square shaped and the windings are put on one side. The advantage of this transformer is that it has an air gap made with a thin sheet of paper or plastic. As a result it can easily be dismantled. It should be re-assembled without the gap since the circuit is push-pull.

What resistor do you mean? There are timing resistors connected to the 555.
A 39pF timing capacitor will give a very high frequency which would not suit a transformer with iron laminations.

Thanks.
Now I get transformers from pc power supply.it same EE25 ferrite core.
Please Describe the transformer windings.

 

[duke37]

I am not familiar with the EE25 ferrite core. My attempt at taking cores apart have mostly failed due to the glue being so strong and the core breaks.

The primary needs to be wound in a bifilar way. Use two wires wound side by side to make this. The wire must be thick enough to keep the temperature low. The number of turns/volt will be dictated by the frequency and some experiment will be needed to make sure that the core is not saturated.

 

[GPG]

mostly failed due to the glue being so strong and the core breaks.

Heat the core in an oven. They come apart easily Cut the winding off first