I am a beginner and I have got few questions with the first project I am attempting. I am trying to build a reliable timer circuit with three timing options. The use case is very similar to a microwave oven i.e., the circuit should check if the doors are closed, three timing options that can be selected with the buttons, start, stop and pause options for the timer.
I first thought of using a 556 timer(restricting to only two timing options) with a relay. But I also needed a display(lcd displays, not 7 segment leds) and it was not possible to interface a display with the 556 timer.
Another option was to go with a microcontroller like arduino which is easy to work with but I'm sure about the reliability. And they also cost more.
I was searching online and found this circuit for a microwave oven controller. I'm thinking to modify this to my needs than trying to build it from scratch. I have few questions:
The circuit has no fuse on the AC lines. I will be adding a 5A fuse.
Thanks
I first thought of using a 556 timer(restricting to only two timing options) with a relay. But I also needed a display(lcd displays, not 7 segment leds) and it was not possible to interface a display with the 556 timer.
Another option was to go with a microcontroller like arduino which is easy to work with but I'm sure about the reliability. And they also cost more.
I was searching online and found this circuit for a microwave oven controller. I'm thinking to modify this to my needs than trying to build it from scratch. I have few questions:
- I am not able to find AT89C52, what else can I replace it with? Will any 8-bit 8051 do fine?
- I just need to control one relay and 5 input switches. Can I just leave the other ones floating?
- This circuit is designed to work with high power components while my total power usage will be around 80W, do I need to re-calculate for the resistors and capacitors?
The circuit has no fuse on the AC lines. I will be adding a 5A fuse.
Thanks