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just one question tcmtech I though that feedback voltage coming back from the transformer would be dc like I see other feed back circuit have here a diode is this still ok with an ac voltage going to U3a. Just checking Sir
Hi techem how are you I need your urgent help I built the basic half bridge circuit today but I am having some problems my regulator is getting hot and the voltage is droping to about 3v. What number pin is DT on the ic. I dont see that pin on the pdf drawing of the ir2110 Please help me i need your help to correct the prob Waitib your reply ThNK U
Hi techm should I get a 50hz signal at the output of u3a and a 30khz at the output of u3b.Please let me know I am getting the signal on the input of these opamps but not on the output. Please help me here techm i reach so far but got stuck
Hi tcmtech how are you I am longing to hear from you please I am stuck with this circuit now and need your help to get it to work if I could just get some voltage out of it I would be so happy. Waiting for your usual support. Thank u
At startup you should get the 30 KHz carrier frequency on the output of U3b. U3a should start out with no output being it is biased to a low state. When the 30 KHz carrier hits U4 it will be heavily biased to one side of the duty cycle, until C2 charges up, causing the transformer to momentarily start saturating which should change the bias level of U3a letting the 50/60 Hz signal take over and drive the output of the transformer at the right frequency.
It may be necessary to add a small offset voltage to the negative input of U3a by putting three diodes in series with the 4.7 K resistor. Some Lm1458 IC's have slightly different input bias and internal design variances that could be the cause for start up problems without an external 1.5 volt lift up of the negative input. Either way Q3 and Q4 should still be getting driven at 30 KHz even if the 50/60 hz signal is not present anyway.
Then there is the other possiblility that I drew it wrong and have something labled wrong and just cant see it myself! (I have been known to do that some times.)
Thank you tecmtech I thought you would never reply I will check what u say because I am not getting the 30khz on the output of u3b I have it on the input . Next thing as u say maybe u drew it wrong somewhere please check the VSS conection on the ir2110 to see if it goes to +8v or it goes to ground and which connection u label as is DT on the ic . Do please check I am awaiting your reply Sir. Thanks for your support
Hello tcmtech how are you I am now getting the 30khz on the U3b out put now as a matter of fact I am getting 30khz on both hi and lo input of the ir2110 but the output still dont start . Please look over the pin layout agin of the ir2110 and see if there is any wrong labeling . i ask u three times about the pin u Label DT which pin is that please I dont see that pin label on the ic layout and please check the VSS conection. I am waiting your reply Sir. thank you
The block diagrams for the IC's came out of the library for my drawing program and apparently they label the 'SD' (shutdown) pin as 'DT' for what ever reason in the 2110 block. If you had looked at the IC data sheets for the IR2110 you should have been able to figure that out by simple process of elimination as to what pins where there.
As far as the supplying the IR2110 IC with 8 volts you are right I made a mistake and that IC works with an input of 10 - 20 volts so it should have been connected to the input or ran through its own 12 - 15 volt regulator source depending on the actual input voltage level being used.
As far as the three diodes in series with R19 suggestion they should be set up to create a roughly 1.5 - 2 volt bias voltage like a zener diode would do so figure it out from there.
Lastly build circuits like what the IC data sheets say and not necessarily how I have them drawn if something does not make sense. I never claimed to be schematics draftsperson! (Rather I tend to just be a monkey with a keyboard more often than not.)
To be fair I will try and get a corrected schematic drawn up soon. (I kinda wish someone would have caught this stuff about 6 months ago to be honest.)
Thank you very much for your support I will make the corrcection to the Dt and 10v supply What about the VSS connection is it correct?? waiting your reply . Thank you. Did u actually build this circuit
I built it and a few variations of it about 10 years ago when I was considerably far more into designing off grid related electronics and power systems than I am now. Being I have the grid tie inverter stuff perfected to the point of being reliable and workable with my wind generators (when they fly at least) I have not had much use for these types of off grid circuits any more. No real point to them for me any more really.
Anyway a while back I was cleaning up around the house and came across an old notebook I had filled with circuits and schematics and this was one of them that I thought related to the actual circuit I built so I cleaned it up and redrew it on my computer with SYMetrix, only using the IR2110 IC as an output driver instead of a dual power op amp IC, to get more familiar with the drafting program itself.
The VSS pin should be tied to the common line somewhere below C11 like the SD pin is not above it as it got shown. When in doubt read the IC data sheet not my schematic.
Oh well, what do you expect for free info you get from the internet anyway!