Preface:
We have two broken microwaves. One where the lcd screen is extremely dim and unreadable and an older one that doesn't keep time at all. My focus is on the newer one with dim screen but this project can get two birds. The lcd is attached with a plastic ribbon stuff directly to the glass if I remember correctly, regardless, I deemed it unrepairable. I have been itching to do a project using capacitive touch sensing and it dawned on me that this would be the perfect opportunity. The original control panel has lots of buttons for "chicken, popcorn, warm, defrost...etc." My parents don't use any of these features and just prefer setting the time and sometimes the power level. (some of the smallest buttons on the there!) So I decided I would build an entire new control system.
Question:
The "power setting" feature seems to cycle the magnetron on and off for the set percentage of time. One problem I have is for short times the on or off cycle is longer than the set time. (Think of melting a small bit of butter- 12 seconds, 60%) It seems like the minimum on and off times are maybe 10-15 seconds. Is there some duty cycle to the magnetron? I realize PWM is maybe out of the question but would something like 2 seconds on, 2 seconds off be damaging?
Note: I realize duty cycle mainly means the on to off time relationship (ratio) but I am concerned with the minimum on and off times.
We have two broken microwaves. One where the lcd screen is extremely dim and unreadable and an older one that doesn't keep time at all. My focus is on the newer one with dim screen but this project can get two birds. The lcd is attached with a plastic ribbon stuff directly to the glass if I remember correctly, regardless, I deemed it unrepairable. I have been itching to do a project using capacitive touch sensing and it dawned on me that this would be the perfect opportunity. The original control panel has lots of buttons for "chicken, popcorn, warm, defrost...etc." My parents don't use any of these features and just prefer setting the time and sometimes the power level. (some of the smallest buttons on the there!) So I decided I would build an entire new control system.
Question:
The "power setting" feature seems to cycle the magnetron on and off for the set percentage of time. One problem I have is for short times the on or off cycle is longer than the set time. (Think of melting a small bit of butter- 12 seconds, 60%) It seems like the minimum on and off times are maybe 10-15 seconds. Is there some duty cycle to the magnetron? I realize PWM is maybe out of the question but would something like 2 seconds on, 2 seconds off be damaging?
Note: I realize duty cycle mainly means the on to off time relationship (ratio) but I am concerned with the minimum on and off times.
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