Usually, for made a simple square wave generator it use old 555 (you can see my experiments with 555 at Experimente cu “batranul” 555).
I like more CMOS chips… so, I use 4093 series (CD4093, MMC4093, etc) who is Quad 2-Input NAND Schmitt Trigger (see datasheet).
I use schematic for gatted oscillator:
A funny montage is same police lights:
I use Livewire software for simulate this schematic and I made 2 movies:
– original police flasher only CMOS 4093:
– police flasher only CMOS 4093 – logical views
Initial schematic has formulas for calculate times.. imposible formulas at first view, but if study datasheet, we can calculate values.
I calculate times for three value of power suplly:
– for 5V:
– for 10V:
– for 15V:
After that, we can see dutty factor (fu) is about 50%.
Frequency f=k*R*C, so:
Recomadated values are:
For minumum recomandated value for resistor:
For maxim value of resistor:
Theoretical frequency is from 1Hz to 234kHz.
Practical schematic is:
If change just capaciter:
I made a new simulation with Livewire software and new movies:
– simulare functionare oscilator cu poarta CMOS 4093
– oscilator cu poarta CMOS 4093 part2
I found on Minimaxfly channel on youtube a movie named Signal lumineux de Police Flasher CMOS 4093 Electronique who use my schematic: