Full Bridge Inverter with MOSFET and IR2110 gate driver

[khushi_123]

this the circuit i am using..but its nt working..can anyone tell me wat is the mistake???...:sad:

 

[Mehrshad74]

just connect high side GNDs to high side source of MOSs and it will work.
5v is fine for logic side of ir2110 and 12 or 15v is necessary for output stage as you did.

 

[khushi_123]

i will try with the circuit u told..i m attaching the circuit which i m using..i m giving PWM from AVR and inverting PWM through scmitt trigger with RC network at its circuit..tell me if there is any mistake..all the values of capacitors i used are right or is there anythng to change???.

 

[Mehrshad74]

Wrong!
First of all the diode direction is reverse and you have negative dead time.
Second you have to do this:
1-first make an pwm invert with a NOT
2-now connect pwm and pwmnot to 2 seperate RCD like yours but with reverse diode.
3-connect the output of RCDs to 2 NOT gate
4-the output of these 2 are the inputs of ir2110
5-use 2.2nf instead of 10uf in RCD.

the dead time should be positive and both channels need dead time not just one.
Regards

 

[khushi_123]

i am applying 5vp-p. and i m giving PWM from AVR microcontroller..and inverting PWM from schmitt trigger thru RC network at its input..i m attaching full schematic.plz tell me the mistakes in that. also tell me wats RCD u r talking about?????

 

[khushi_123]

plz tell me are u talking about all the diodes???...and make me clear wat is RCD??...

 

[Mehrshad74]

No!
Just the diode beside 1k resistor near the 7414.
RCD = Resistor Cap Diode combination near the 7414 for inverting pwm.

 

[khushi_123]

ok..i got it..thank u so mch for ur help..
tell me plz that rest of the connections and values are right or is there any mistake in the schematic??..

 

[Mehrshad74]

The Last one was OK except for what I wrote in the previous post.
A 5ohm series resistor with bootstrap diodes is recommended and note that this circuit will not work with 0 and 100% duty cycle.
this is because of bootstrap charging of high side drivers that need low side switches turn on occasionally.

 

[khushi_123]

alright..i will connect vs to ground and will check that..
f=4khz , vdd=5v ,vcc=12v ,duty cycle=50%
plz tell me the value of bootstrap capacitor..i m not getting it..22uf is ok or shud i change that???..help..

---------- Post added at 09:57 ---------- Previous post was at 09:51 ----------

ok i will connect vs to ground and will check that..
f=4khz , vp-p=5v ,vdd=5v, vcc=12v,duty cycle=50%
plz tell me the value of bootstrap capacitor..i m nt getting it..22uf is ok or shud i chnge that???...

---------- Post added at 09:58 ---------- Previous post was at 09:57 ----------

ok i will connect vs to ground and will check that..
f=4khz , vp-p=5v ,vdd=5v, vcc=12v,duty cycle=50%
plz tell me the value of bootstrap capacitor..i m nt getting it..22uf is ok or shud i chnge that???...

---------- Post added at 09:59 ---------- Previous post was at 09:58 ----------

ok i will connect vs to ground and will check that..
f=4khz , vp-p=5v ,vdd=5v, vcc=12v,duty cycle=50%
plz tell me the value of bootstrap capacitor..i m nt getting it..22uf is ok or shud i chnge that???...

 

[khushi_123]

i have made that schematic on bread board..but the problem is that one of the ir2110 is getting hot..i have cross checked all the connections..but the connections are same for both the ics..kindly tell me what is the mistake????....
f=4khz , vdd=5v ,vp-p=5v ,vcc=12v ,duty cycle=50%
how can i check that ic if its working or not..shud i change the ic??...

 

[ALERTLINKS]

Sorry about the circuit, it won't work with Vs connected with ground. Connect wth common node of relavent common node Of FETs along with -Ve pin of boost capacitor. St duty cycle not more than 98%.

Both sides are identical.
With 50% duty cycle, The common node of FETs will show 1/2V of Vcc with an analog meter. Swap both ics with one another and see if the same IC is getting hot.

 

[khushi_123]

ok so tell me that my schematic is correct now??..

 

[khushi_123]

same ic is getting hot..is it faulty ic??..wats the fault??..shud i chnge th ic??..i m giving attached pwm at input..bt still its nt working..will it work at 50% duty cycle??..

 

[Tahmid]

It looks completely fine. The 1N5817 diodes across the MOSFETs aren't required; at 4kHz, the body diodes of the MOSFET are fine. One thing I told you at the other thread is that, you should add a 1k resistor between the gate and source of each MOSFET.

 

[ALERTLINKS]

You can check ICs individually. Normally its faulty when it is getting hot. Disconnect supply of one side (12V to FETs and to IC) and check for output on center node of FETs and ground. Similarly check other side. In the picture posted, duty cycle is about 20% not 50%. Does it show full 12V swing? In full bridge operation it will show +/- 12V.



























-

 

[khushi_123]

i m giving pwm from avr controller..its peak to peak is 0-5v..

 

[ALERTLINKS]

As Vdd is connected with 5V, not 12V in your schematic, its ok for logic level operation. Most probably 5V supply to avr and Vdd of IR2110 are common, its good. Your circuit should work. Set duty cycle of PWM correctly. Is your load connected between two common nodes of FETs

 

[khushi_123]

its working..when i made it on vero board..thank u so mch for ur help..its a great help..

 

[ch wazir]

i am applying 5vp-p. and i m giving PWM from AVR microcontroller..and inverting PWM from schmitt trigger thru RC network at its input..i m attaching full schematic.plz tell me the mistakes in that. also tell me wats RCD u r talking about?????

Dear Khushi,
Didn't you read my previous post where I told you that yours all circuit is good one and workable.lot of people confusing you.Previously I prepared an inverter using the circuit like yours and is working fine.I think you only need a buffer stage and amplifier stage between the input of ir2110 and output of microcontroller,moreover you need to replace 22uf cap with 68 uf/50volts and bootstrap diode with 1N4007 which is easily available.Regards