Solving PWM Issues with TL494 - Get 50% Duty Cycle

  • Thread starter Thread starter kk116
  • Start date Start date
  • Tags Tags
    Pwm
AI Thread Summary
The discussion revolves around using the TL494 PWM control IC for building an inverter, specifically aiming for a 50% duty cycle. The user successfully achieved the correct frequency but struggled with duty cycle adjustments, initially reaching only 10%. Suggestions included adjusting the voltage on the feedback pin to regulate the duty cycle, which proved helpful after varying the reference voltage. The user is now seeking advice on driving MOSFETs with the PWM signal to generate AC output. Overall, the conversation highlights the challenges and solutions related to achieving the desired PWM characteristics with the TL494.
kk116
Messages
8
Reaction score
0
Hi,

I am trying to build an inverter and i am using Tl494 for my PWM, i am getting the right frequency but am not getting the 50% duty cycle. Can anyone suggest me any ideas on how to adjust the duty cycle for Tl494
Thanks.

Krishna
 
Engineering news on Phys.org
kk116 said:
Hi,

I am trying to build an inverter and i am using Tl494 for my PWM, i am getting the right frequency but am not getting the 50% duty cycle. Can anyone suggest me any ideas on how to adjust the duty cycle for Tl494
Thanks.

Krishna

Why are you looking for 50% duty cycle? The max in the datasheet is 45%, and the duty cycle would be dependent on ... Quiz Question -- dependent on what?
 
I will use MOSFETs and i will use PWM to turn on or off. I need the 50% duty cycle to turn the mosfets on and off for same period.
I am trying to make an inverter for 50 Hz. The example given in the data sheet gives the duty cycle of 45% but has max frequency. I want the PWM osc. frequency to be 50 Hz. And I AM NOT SURE IF PWM OSC. FREQ WILL BE MY MOSFETs OUTPOT FREQUENCY OR NOT?
Moreover, i was able to get the PWM to 50 Hz but my duty cycle was 10% and i tried increasing the reference voltage but still didn't help.

Thanks
 
The duty cycle can be adjusted by adjusting the voltage on the feedback pin(3). This is normally used for voltage regulation in a power supply.
 
Thanks again, I had tried that before but I had ref v to be 5v. I think it was a problem since my comparator triang wave had pk-pk of 2.6v I was able to vary now with ref v from 0-.7v. Thanks again for the information
Now I have to drive MOSTETs with this pwm signal. Can I get heads up on how to make MOSFETs switching to get AC out?

Thanks
 

Thread 'Underwater piezoelectric sensor array receive sensitivity'

Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
View full post »

Thread 'Question about bonding ground and neutral'

I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
View full post »

Thread 'Following up on the recent thread about Earth Resistance measurements'

I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
View full post »

Similar threads

Stepper motor current/torque model
Replies
1
Views
975
Synchronous MOSFET Driver not functioning when voltage already present
Replies
2
Views
2K
Inverter circuit shoot-thru HELP
Replies
2
Views
2K
MOSFET not working with digital input gate signal, Help please
Replies
25
Views
5K
Boost converter duty cycle in DCM
Replies
23
Views
5K
Can Resonant Frequency Disassociate Water Molecules?
Replies
12
Views
3K
Changing the duty cycle of a PWM signal
Replies
10
Views
6K
Why Are There Notches Instead of Square Wave Voltage in My Flyback Transformer?
Replies
2
Views
2K
555 timer, 50% duty cycle astable, run from 5V
Replies
38
Views
22K
Getting a High Speed Synchronous N-Channel MOSFET Driver working right
Replies
39
Views
5K

Hot Threads

Recent Insights

Back
Top