iHeat

Timer based RC circuit has been chosen for its advantages. One of the main advantages – the block wave output
– allows abandoning the ADC in the circuit and using cheap microcontroller for data acquisition.
Choosing this concept requires us to deal with its disadvantages. This is done by the 2 following methods:
 Using the enable signal for each of the oscillators. Say, circuit one is enabled for 1 second, then disabled.
When circuit 1 is off, circuit 2 turns on and operates. This loop runs continuously and can include n-number
of circuits. This prevents crosstalk between circuits with different frequencies.
 Output of each circuit is fed to the low pass filter with the cutoff frequency 10x above the fundamental. This
smoothes out the edges of the square wave and eliminates the hard switching ringing on the wave edges.