Greetings,
I'm having a issue with a Gate switching power supply using a IR2110. The problem is in the bootstrap circuit that is being used isn't working.
I looked at different configurations but I haven't seen this type of design.
The original problem is with no gate signal the IC voltage on Vb Vs and Ho were reading 50 vdc. So I changed C6 and C3 but I don't think
I used the correct diode. After I changed the parts I still don't get the correct voltages compared to the LTspice files that I have attached.
I have no idea what the original schematic is because there is none.
I would like to change d3 and see if that corrects the problem but I don't know what type number diode to use. I can't identify the part number.
Thanks in advance,

Jeff M.

 

The original IR development board used a 10KF6 (600v 1amp).
Also see http://tahmidmc.blogspot.com/2013/01/using-high-low-side-driver-ir2110-with.html
And there is a site for calculating the capacitor needed for the diode circuit.

 

The Silicone Labs bootstrap calculator appears to have been taken over.
https://www.skyworksinc.com/tools/bootstrap calculator

 

D3 needs to be a 400 to 600V diode, very fast. Probably 1A
D3 must connect V1 (12V) to C1. This is how C1 gets charged up.

R4, No.
R1, D1 is not doing what you think.

When M1 is on current builds up in L1. When M1 opens up the point "out" will go below ground and brake things.

That are you trying to make?

 

D3 needs to be a 400 to 600V diode, very fast. Probably 1A
D3 must connect V1 (12V) to C1. This is how C1 gets charged up.

R4, No.
R1, D1 is not doing what you think.

When M1 is on current builds up in L1. When M1 opens up the point "out" will go below ground and brake things.
View attachment 286731
That are you trying to make?

I agree so I attached a few pictures so you can take a look.
Thanks again,

Jeff M.

 

I agree so I attached a few pictures so you can take a look.
Thanks again,

Jeff M.

I will tell you that the circuit is designed to regulate the dc voltage to around 150vdc.
Could that be the reason the circuit is designed this way?
Thanks,

Jeff M.

 

Thanks for the information. Also please find the modified files.
Thanks in advance.

Jeff M.

 

I will tell you that the circuit is designed to regulate the dc voltage to around 150vdc.

I see the 320V input. Where is the 150V output?
Would you like one of us to make a circuit that regulates to 150V? What current?

 

I see the 320V input. Where is the 150V output?
Would you like one of us to make a circuit that regulates to 150V? What current?

The 150 vdc output is from L1 to ground. This circuit is used in equipment to drive a stepper motor.
I'm not sure about the output of 150vdc but after I added the diode resistor circuit D1,D7,R1 and R8 I noticed the output
dropped to around 150vdc. So I'm going by the troubleshooting guide.
I would like to have the circuit work without any major modifications. if you need any extra information
please let me know.
Thanks in advance,

Jeff M.

 

I agree so I attached a few pictures so you can take a look.
Thanks again,

Thanks for your help. I looked at the board trying to make sense of the circuit. Your right about D3. I missed the anode which has to be connected to VDD. Now the circuit makes more sense.
Best regards,

Jeff M.

I agree so I attached a few pictures so you can take a look.
Thanks again,

Jeff M.

Thanks for your help. I looked at the board trying to make sense of the circuit. Your right about D3. I missed the anode which has to be connected to VDD. Now the circuit makes more sense.
Best regards,

Jeff M.

 

I will tell you that the circuit is designed to regulate the dc voltage to around 150vdc.
Could that be the reason the circuit is designed this way?
Thanks,

Jeff M.

Which voltage is it trying to regulate?

 

Which voltage is it trying to regulate?

I believe it suppose to regulate around 150VDC at L1 with respect to grd.
Thanks in advance.

Jeff M.

 

I believe it suppose to regulate around 150VDC at L1 with respect to grd.
Thanks in advance.

Jeff M.

You can't regulate a fixed DC voltage across an inductor, because the current required would be infinite.
I = ∫(V/L) dt
for V = fixed I=Vt/L

 

You can't regulate a fixed DC voltage across an inductor, because the current required would be infinite.
I = ∫(V/L) dt
for V = fixed I=Vt/L

I understand that but I didn't design the board the information I have is the voltage is suppose to be around 150vdc.
I had to try to reverse engineer the circuit board to try to repair the motor drive PS but I do know that they use the same
chip to drive the motor. The input pulse is controlled by the microprocessor. So I assume the voltage is controlled by
changing the pulse width? But I'm not sure.
Thanks for your reply.

Jeff M.

 

I understand that but I didn't design the board the information I have is the voltage is suppose to be around 150vdc.
I had to try to reverse engineer the circuit board to try to repair the motor drive PS but I do know that they use the same
chip to drive the motor. The input pulse is controlled by the microprocessor. So I assume the voltage is controlled by
changing the pulse width? But I'm not sure.
Thanks for your reply.

Jeff M.

It doesn't make any difference who designed the boards, it is still impossible to have a regulated DC voltage across an inductor.
Your assertion that it regulates the DC voltage across the inductor must therefore be incorrect.
When you find the real purpose of the circuit I'm sure someone will be able to help you achieve it.

 

It doesn't make any difference who designed the boards, it is still impossible to have a regulated DC voltage across an inductor.
Your assertion that it regulates the DC voltage across the inductor must therefore be incorrect.
When you find the real purpose of the circuit I'm sure someone will be able to help you achieve it.

No I understand what you mean but the inductor is in series with the motor drive circuit. The only reason I added is to make simulation
circuit work. The output uses a 220UF 400vdc capacitor across the output.