Hi.
This Is A Ballast Circuit For 8 to 40w Fluorescent Lamp.

I Want to change It.I Want to Replace The Ir2155 Ic with the Astable Circuit Below at 45 Khz Frequency.


Outputs Of OpAmps will Directly ConnectTo The Bases Of Two Transistors MJE13005 That Replace With Power Mosfets , IRF720.
no change with other components or connections.
Whats your Idea?
It Will Work?
Thanks.

 

15v Supply Voltage For CD4047 And LM358 IC`s Will Be This In The Original Schematic:

 

The LM358's can only handle a small fraction of the IR2155's current. Unless you use transistors driven by the op amps to increase the current drive, your circuit will not work.

 

Your 100k to 4.7k voltage divider provides only 3mA for the zener diode, oscillator and dual opamp. Then there is not enough current for them and not enough current available for anything else. The 100k resistor will be hot!

The fluorescent light tube needs 311V switched.
The old LM358 dual opamp has trouble at frequencies above 5kHz.

 

Non-isolated power supplies are seldom safe.

 

Thank You Very Much.

And What About This?

 

I Have found another Ballast Circuit And Interested Me!
I Don`t Know If It Works Or Not! For 40W T12 Lamp.

Can You Help Please?
Original Source:
http://schematics.blogspot.com/2006/10/tubelight-electronic-choke.html

 

md, could you please teel mw why you want to change the parts or circuit like you'd proposed? better yet, what is it your goal.

the circuit you proposed in fig. 555.jpg is faulty. the configuration for Q2 would burn it. and the lower mje as well.

 

o,Yes; Your Right.Thanks.
You Know The Original Circuit is some expensive.and at least in my country is not acceptable in compare with an electric Ballast Choke price.

Now what about The last circuit in my previous Post?
can you tell me about Part Numbers and windings please?
And It Works?!!!
Thanks..

 

i couldn't read the circuit well, but i guess it's a common commercial one. it's the best one you should build, if price matters.
the problem is that electronic ballasts use ferrites transformers and inductor which sizes and values you'd better obtain by looking at a working model.
I suggest that you obtain a commercial one, and build one according to it.

 

Thank You.
I Think The Schematic Needs a Diac.