Hello friends this post is about "induction heating" project on which i was working in final year.
I have already post about
PWM pulses generation and
MOSFET triggering with microcontroller which are two important aspects I found out during my final year project.
Here is the Pwm scheme which i have used to generate pulses.
![PWM pulses to mosfet bridge pwm pulses mosfet bridge induction heating](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwyxZB187z56K1jjYMrau4xATWx7gkBqE3Te0CYbZLp-EoDUSHGtmXJi69KaZt8JLv_jHosk1PLs0aI6BF5jDb-Jw59OkM-ZFrAbcm6sEiUAA3fprJjJlDjTg5tVv8nhQG4Sj4BJSupe_X/s640/triangular+waves.jpg) |
Triangular wave and two reference levels |
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- First of all I generated a triangular wave (inside microcontroller) this is called Phase correct PWM in AVR microcontroller.
![PWM pulses for inverter pwm pulses with guard band with microcontroller](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjCdpdT5wvD8dSxruaz4ImydKbylSiVoaHIN4-wxEn3E_kTa6ON1s7pDNLapoA5qa55Rkbi1-ZMbp0D-HX46K51Bb-e_HnKAMCuoFKtYpgL_Zo8Y_XMU2OlNvQcObYAzQkS75nEObNtOeP/s640/triangular+waves%252Bpwm.jpg) |
Pwm pulses with guard band |
- Then I generated two levels with which I want to compare my triangular wave... which leads to the following type of pulses with guard band.
![Gate pulse for inverter with guard band](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiwhwm7UvMRDQvFYFJ6oESktIGZFJI45rW9Pm7pJtsanRVjHQfoHwxm91xYX8TUTfdHvbomkZurBc-PJLhZ4smwUU11o0VI2afQGNSXBKe9DjkAjLTvr0-f1OOTb6GjWOpIQfwoC0lfzaA7/s640/gate+pulse+logic.jpg) |
Gate pulse logic |
- here is the logic which i used to generate gate pulse.
- these pulses are then applied to MOSFET as discussed in this post via opto-couplers to this bridge configuration
![inverter bridge simulation inverter bridge circuit](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCk-Pw9OA29jtyAxat5H0uZnSh6VTqbQ-5CZr9knHrdrE5VlFxjlbkbvhzyAFpk9IGBc0teL-PZg5AhXHj7Nnqs_HWkHz2SAK5dsMgyV_d8VLXZ9JOSuZy84pChAn_ooZ3t-egkb6LSb8l/s400/Inverter+bridge.jpg) |
Inverter bridge |
- with inductor and capacitor series resonant circuit as load I got this current output waveform from the load.
![inverter with inductive and capacitive load inverter with inductive and capacitive load](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHSS4XVsfEzKcidw23Eri098zl5htDoMkDmnpB1_TP5oopOpP6k66aQZseaNRV9QlKq_OAwKqC8dSPEkguzZKQC__i1zkLxyBvbRmgS-Q65Mo2hyphenhyphenMtelffJmkh4tWdDI0_wsGvrK-6o00n/s640/current+waveform.jpg) |
Current waveforms of inductor |
Questions and suggestions are always welcomed in comment box.......so feel free to comment.
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