salut everyone !
I have some problems about triggering mosfets. The main object is control a full bridge maded by mosfets which is irfz44n in this case.
When i plug the bridge configuration gates cable through the signal cable (signals coming from ir2101,25kHz) ,the signals are changing anormal ! Like this;

When i remove ch2 signal from breadboard ,this one is happening;


Aftet i remove ch2 signal, the output is not changing. Its so much anormal dont know why !

İs there any idea ?

 

Give us a schematic, please, else we are just guessing.
Also explain where on the schematic you see these waveforms.

 

You mentioned 'breadboard'. Long wires and poor contacts are a common cause of problems on breadboarded circuits.

 

Give us a schematic, please, else we are just guessing.
Also explain where on the schematic you see these waveforms.

Here you go.
G1 is ch1 and G2 is ch2. The wire which im removing from breadbord is G2. And as i said the output waveform is not changing. Also ,at very right mosfets are wired too but the scheme is from pretty old times.

 

You mentioned 'breadboard'. Long wires and poor contacts are a common cause of problems on breadboarded circuits.

Yeah i know the breadboard are bad for signal processing. Im building something new and movin stepbystep of signal processing. So i couldnt use pcb.
Im actually wondering what professionals use for development circuitry? Breadboard or something better ??

 

Give us a schematic, please, else we are just guessing.
Also explain where on the schematic you see these waveforms.

Forgot to say scoping from before the mosfets gate terminal (aftet the 100ohm resistor ). There is a anormal signal from.

But G2 is good and as i expected.

 

Could you enlarge the signal?

 

Here it is ;

Could you enlarge the signal?

I realy need some help. Stocked here !!

 

From the waveform that it looks like a square wave through a RC differential circuit.

You said that the G2 is oK, do you have change the n MOSFET for the G1? (the left top of the bridge)

 

From the waveform that it looks like a square wave through a RC differential circuit.

You said that the G2 is oK, do you have change the n MOSFET for the G1? (the left top of the bridge)

Before the mosfet driver (G2 in scheme) is good. But after the resistor ,signal is changing.

 

And note that when i remove G1’s signal , the anormal wave is gettin normal and exect same before mosfet driver which i want to see.

 

what are the number of MOSFET drivers?

 

In your schematic the gate driver of the high-side FET is not connected correctly. The Vs terminal should connect to the source of that FET, not to ground. The way you have it, the bootstrap capacitor can't do its job and the high-side FET won't turn on fully.
Why do you have the 0.1uF caps from the gate resistors to ground?

 

In your schematic the gate driver of the high-side FET is not connected correctly. The Vs terminal should connect to the source of that FET, not to ground. The way you have it, the bootstrap capacitor can't do its job and the high-side FET won't turn on fully.
Why do you have the 0.1uF caps from the gate resistors to ground?

First of all thanks for advice.
And the capacitor (0.1uf used at past , im not using it now ,i didnt notive that sorry).

And i didnt know i should connect Vs through supply voltage thanks for correcting me.
What about spikes ? Will it be normal after i connect Vs to supply voltage ??

 

what are the number of MOSFET drivers?

I think you the name of them. Ir2101. Both of them.

 

i didnt know i should connect Vs through supply voltage

The Vs pin of the IR2101 should not connect to the supply voltage. It should connect to the Source pin of the high-side FET and the Drain pin of the low-side FET.

 

I think you the name of them. Ir2101. Both of them.

Where did you get the wires connection of h-bridge?

IR2101 MOTOR DRIVER CIRCUIT DIAGRAM
https://320volt.com/en/h-bridge-dc-motor-driver-circuit-with-ir2101/

Puente h con ir2101 y mosfet

20AMPS H-BRIDGE DC MOTOR DRIVER WITH CURRENT AND FAULT FEEDBACK USING IR2104-IR2101 IRFP4468
https://www.twovolt.com/2016/07/28/h-bridge-10amps-36v-dc-ir2104-ir2101/

 

thanks for all respons.

The Vs pin of the IR2101 should not connect to the supply voltage. It should connect to the Source pin of the high-side FET and the Drain pin of the low-side FET.

i have made correct wiring.thanks.

Where did you get the wires connection of h-bridge?

IR2101 MOTOR DRIVER CIRCUIT DIAGRAM
https://320volt.com/en/h-bridge-dc-motor-driver-circuit-with-ir2101/

Puente h con ir2101 y mosfet

20AMPS H-BRIDGE DC MOTOR DRIVER WITH CURRENT AND FAULT FEEDBACK USING IR2104-IR2101 IRFP4468
https://www.twovolt.com/2016/07/28/h-bridge-10amps-36v-dc-ir2104-ir2101/

those links are so helpful. thanks for sharing.

now today at first lights , i rebuild my diagram and draw it on paper.
this diagram is exectly same of my circuit.

although the correct wiring the circuit is still has some problems.i printed laptop screen of oscilloscope step by step.

at the diagram A and B are the main switching signal which is coming from another board. The supply voltage is 12V . Mosfet driver's and mosfets(irfz44n) are suppling same source. Also GND wiring is correct and all wired together at common GND.

1)-------------

the first problem is HO pins of the mosfet drivers. Both of them has anormal activity. This one is very left one.
CH1 is A signal which is comming from another board. Ch2 is output of the HO pin which is at the very left. When it must turn off the mosfet , the signal is anormally and the exectly revers of the B signal. Dont know why???????

At the very left mosfet driver's LO pin is working fine and exectly same of the signal B , which i want to see.

2)------------------

The second problem is at the very right mosfet driver's. It acting anormally like first one.

Ch1 is main signal(HIN) which is B now. Ch2 is output of the HO pin at the very right mosfet driver's. When driver should switch the mosfet , the output of the driver are acting like only one pulse. Dont know why????????

The LO pin which is at the very right mosfet driver's is working fine and the waveform is exectly same of i want to see.

As you can see , both of the mosfet drivers have some problems at HO pins. I should say that , i already changed the mosfet drivers and mosfets with new ones, but the result is the same.

NOTE1: When i remove the voltage cable of mosfets, the signals are coming back to the normal. But when i replug the cable of 1-3th mosfets drain's , the signals are acting anormally as i told above.

i really needd some help here , cause im not doing anything for now .....((

 

this diagram is exectly same of my circuit.

1) You show A and B as inputs to the Hin and Lin pins of the left-side IR2101, but the Hin and Lin pins of the right-side IR2101 are apparently floating (unconnected). Leaving CMOS inputs unconnected (unless specified in the datasheet as ok) is bad practice and can cause various problems.
2) Was there a load connected to the FET bridge when you took the scope pics? If not, repeat the measurements with a load (say ~1k) connected.
3) You've put some designators (C1, C2, .....) on the schematic. It would help if you use them when discussing the waveforms and circuit.
4) What IC supply voltage are you using? The IR2101 datasheet specifies a minimum of 10V and has an undervoltage lockout of ~8V. Your scope pics suggest you are using only 5V (if I'm interpreting them correctly). That's fine for the Hin and Lin inputs but not for Vcc. If Vcc is only 5V it's no surprise you get odd results.

 

1) You show A and B as inputs to the Hin and Lin pins of the left-side IR2101, but the Hin and Lin pins of the right-side IR2101 are apparently floating (unconnected). Leaving CMOS inputs unconnected (unless specified in the datasheet as ok) is bad practice and can cause various problems.
.

1)They wired. There is no space on the paper so i desided to show it with arrow down bellow of the ir2101 at very right one.

2) Was there a load connected to the FET bridge when you took the scope pics? If not, repeat the measurements with a load (say ~1k) connected.

2)i ll try as soon as i can and i let you know.

3) You've put some designators (C1, C2, .....) on the schematic. It would help if you use them when discussing the waveforms and circuit.

3) okey.

4) What IC supply voltage are you using? The IR2101 datasheet specifies a minimum of 10V and has an undervoltage lockout of ~8V. Your scope pics suggest you are using only 5V (if I'm interpreting them correctly). That's fine for the Hin and Lin inputs but not for Vcc. If Vcc is only 5V it's no surprise you get odd results.

4) The oscilloscope didnt set of voltage measurement, it has been set for observe the signal. The signal +Vpeak=10V. The negative spikes are max -1.2V. At the diagram (you can see top left corner of the paper) 12V. The power supply is a good one and also i added some of the big condansators at the between 12V and GND. It has pure DC voltage. Also as i said before, all components of the circuit suppling by this source(including IR2101's and IRFZ44n's)