Dear sir,
would you check the attached file, it is a power module including a boost and an inverter. by the way, the duty cycle has a great influence on the output voltage.
If you divide whole circuit into different sections according to functions, it will be lot more easy to end up with a working prototype. For example,
1. PWM signal generation.
2. Driver stage for output power switching devices.
3. Output stage
4. Voltage regulation.
5. Protection against overload etc.
For 12V operation it is better to use push-pull output stage not half bridge. This depends according to power requirments. You have to use a transformer to step up voltages. Either ferrite core for high frequency or iron core for low frequency.
Dear ultrasonic,
Please send me the circuit as it is implemented. I wonder if these signals are for the boost converter of for the half-bridge ?
IR2110 has to give you a signal HO-vs but when you put the oscilloscope probe to LO (oscilloscope ground not connected), you get signal.
C3, filter capacitor 2.2uF is of low value. Increase it to 330uF. It has to filter mains 50Hz from rectifier bridge. Otherwise circuit seems ok.
Dead time is of small duration( around 1uS to 4uS). The rest of period is controlled by pwm signal.
LO and HO signals seems ok showing some 40% duty cycle. What frequency is used? Vs is square wave, it should'nt be. It may be due to low value filter capacitor on mains, if it is 50 Hz. What is amplitude of this signl.
Check for IR2110 And FETs, if they are not damaged. There should be some output.
You should expect signal like this of 35KHz if checked against 1/2 Vcc volts.
But due to use of series capacitor in output, the potencial when both FETs are off (floating) will be different but voltage swing to full Vcc when Upper fet is on and 0V when lower fet is on.
C3, filter capacitor 2.2uF is of low value. Increase it to 330uF. It has to filter mains 50Hz from rectifier bridge. Otherwise circuit seems ok.
Dead time is of small duration( around 1uS to 4uS). The rest of period is controlled by pwm signal.
LO and HO signals seems ok showing some 40% duty cycle. What frequency is used? Vs is square wave, it should'nt be. It may be due to low value filter capacitor on mains, if it is 50 Hz. What is amplitude of this signal.
Check for IR2110 And FETs, if they are not damaged. There should be some output.
hello mr.alertlink and ultrasonic,
I enjoyed the discussion of you both people but as far as i concluded,the question of MR.ULTRASONIC is that how he can reduce/increase the duty cycle of his input squre wave generating by the micro-controller prior to feeding the high/low side ir2110 and then to half bridge.plz if u don't mind tell him and me also if you hve' some idea of this e.g 50% to 25% etc.regards
After spending lots of time, I can say that the output duty cycle is changed by increasing/decreasing of deadband time between two PWM signals.
What is value of voltage swing and frequecy is in output.
This waveform can be developed due to capcitative load. This capacitor loading could be even from oscilloscope leads. If a capacitor is on output it is charged when output is high, when fet is turned off, the capacitor retains charge aoutput shows full positine volts until lower fet turns on and capacitor is dicharged. But now when lower fet is turned off, capacitor remaind discharged showing 0v on output.It seems there is square wave on output. In actual use, PWM will work.
This circuit will help testig PWM and reading and viewing actual condition using three same tupe of small ac 220 volt bulbs
Bulb2,3 are in series and connect to 310 volts. They will half lit equally. Their center point will be 155V. bulb1 is in series with center point output of hbridge. When switching tie of both feis equal it will be 50% voltage level , there be no current through bulb1. With change of current it will lit and luminance of bulb2,3 according to pwm applied. most important on bulb1 scope can be connected to see actual waveform.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?