Update.

I've re-done the entire circuit, this time adding current sensors and an EMI filter to prevent the circuit from sending that pesky noise down the line that was affecting other controllers. I still need to add some more lines of code to the MCU to make proper use of the current sensors, but that should prove to be fairly simple.

​

The sensors are connected to an IC that outputs a lineal 0-5V signal depending on the RMS current being consumed by the motors. This signal is then connected to a comparator, whose other input is connected to a pot configured as a voltage divider. The comparator's output is connected to the MCU, which will reverse the motor a little bit before attempting to feed it forward again. It will then stop the motor and raise an alarm if this condition happens too many times.

 

Hi C, is this still for the drilling machine? Have you tried the carbide drills yet? How are they working out?

 

Hi C, is this still for the drilling machine? Have you tried the carbide drills yet? How are they working out?

I'll be trying them out in a few days, and then I'll let you know. But this is the fourth machine of its kind that I've built. With several important improvements on each following version, of course. So yes, I do have prior experience with specially manufactured carbide drills. They're far superior to HSS in finishing (less burring, and more perfectly round holes) and stay sharp for a far longer time when drilling abrasive materials. I'd say about 15 to 20 times longer, in my experience.

 

And yet another one. What are C6 and C7 supposed to be doing in this circuit? Can I just do away with them? I don't even know why I put them there in the first place.

View attachment 121474

Can you attach the sch file of ltspice... The IR2101 file is what I am not able to find in Ltspice

 

Can you attach the sch file of ltspice... The IR2101 file is what I am not able to find in Ltspice

Have you tried joining the LT Spice forum? They have many models for ICs there.
https://groups.yahoo.com/neo/groups/LTspice/info

 

Can you attach the sch file of ltspice... The IR2101 file is what I am not able to find in Ltspice

I couldn't find it either, that's why I used the IR2104 instead, which is very similar. You can download the LTspice model for that part in this post.

 

It works!!!! And I adjusted the bootstrap caps to 220nF, which I have readily available. Another advantage is that I'll only need 2 outputs from my MCU to drive the thing. I also set the switching frequency back to 12.5 kHz and it seems to be working smoothly.

View attachment 105767

Thank you both, Alec and Ron. Now I'm going to order a few IR2104, some extra FDA33N25, and a few TVS see how things work out.

One question, though. If I had wanted to run the thing at 100% duty cycle (this is not the case), I realized that this circuit wouldn't be viable. Maybe for that purpose it would've been best to use floating supplies to drive the high side fets (as I explained in post #39), and 2n2222 transistors to drive the low side fets, as in my OP?

The 4 diodes that you used in the .sch d1, d3, d5, d6 is it for giving input to the circuit (pulse, sine)

 

The 4 diodes that you used in the .sch d1, d3, d5, d6 is it for giving input to the circuit (pulse, sine)

Those four diodes rectify a 120VAC source to feed the circuit pulsed DC.
Just look at the green trace in the simulation. It varies between 0 and 170V on a 120Hz frequency.

Since the wave is half a sinusoid, it averages at 120VDC. But I'm using a duty cycle on the h-bridge that will never allow it to pass the 90VDC rms that the motor was designed for.

 

In my case

i am currently working on the schematic
Instead of a ECU or a motor , I am firstly placing a simple resistor in....

As u said in your previous comment, I too need to drive the circuit (with 0-5V , and freq less than 1KHz) An sine wave is also possible with suitable parameters in Ltspice (VAC)

I have to check across the resistor if, i get the voltage somewhere near 12V-14V....(is it feasible )

what do you suggest ? will post my .sch once done

 

In my case

i am currently working on the schematic
Instead of a ECU or a motor , I am firstly placing a simple resistor in....

As u said in your previous comment, I too need to drive the circuit (with 0-5V , and freq less than 1KHz) An sine wave is also possible with suitable parameters in Ltspice (VAC)

I have to check across the resistor if, i get the voltage somewhere near 12V-14V....(is it feasible )

what do you suggest ? will post my .sch once done

My circuit will work just fine for your application using a 12 to 14VDC source in it, instead of a rectified 120VAC as shown. You could build your circuit exactly like mine, and it will work perfectly with a properly rated resistor. Just make sure you check the code thoroughly first. If you accidentally turn both mosfets on at the same side of the bridge simultaneously, they will be destroyed.

 

Thanks for the suggestions, I used the IR2101 and gave it a go it says cant open lib file IR2101,

I will use the one IR2104 , as you suggested in previous one. And check if i can apply it in my application.

Signing out now

Will rivert with the .sch

 

Did you mean the circuit in #129 ..??

I have started building the circuit in Ltspice .

 

Did you mean the circuit in #129 ..??

I have started building the circuit in Ltspice .

I've gone through my posts, and I couldn't find my latest circuit. At the risk of double posting, here it is.



I've also included the .asc file for you to play with.

 

Hey C, did you know that you can hide the part names and other texts from the schematic, instead of bunching them in a corner? Use ctrl-right click and then double click on the X next to what you do or don´t want shown.

 

Hey C, did you know that you can hide the part names and other texts from the schematic, instead of bunching them in a corner? Use ctrl-right click and then double click on the X next to what you do or don´t want shown.

No, I did not know that.... excellent tip, thank you!

 

I've gone through my posts, and I couldn't find my latest circuit. At the risk of double posting, here it is.

View attachment 130692

I've also included the .asc file for you to play with.

Just gave it a try to run the current .sch in my ltspcie

It says couldnt find the lib file IR2104g ??

I tried writing in spice directive the location where the IR2104 symbol and all is present ....as there is only sub and symbol in the file ..

What needs to be included?

 

Just gave it a try to run the current .sch in my ltspcie

It says couldnt find the lib file IR2104g ??

I tried writing in spice directive the location where the IR2104 symbol and all is present ....as there is only sub and symbol in the file ..

What needs to be included?

Here you go. Just copy the .sub and .lib files into the "\Program Files\LTC\LTspiceXVII\lib\sub" folder, and the entire "ir21xx" folder into the "\Program Files\LTC\LTspiceXVII\lib\sym" folder

 

No. If you're running the latest version of LTspice then the files should be added to the "Users\User\Documents\LTspiceXVII\lib\......" folders instead.

 

No. If you're running the latest version of LTspice then the files should be added to the "Users\User\Documents\LTspiceXVII\lib\......" folders instead.

mmmhhhh.... now that you're mentioning it, I found those files in both folders! I didn't know about this change in LTspice's latest version ... @Bhargav Jani, I advice you to do as Alec_t is suggesting instead, he's more knowledgeable than I in these matters.

 

Thank you ....

I will do it.