The formula used is as follow:t= 1.1RaCRa is the total of R4 and R3. So, the minimum pulse time when R4 is set to 0, is:t= 1.1 x 8200 x 0.0000001t= 0.902 msNote that this minimum pulse width time is longer than the trigger pulse to ensure that the pulse width generator doesn't constantly generate0.65ms pulses one after the other, but at a steady +- 50Hz interval.WhenR4 is set to maximum, the time ist= 1.1 x 18200x 0.0000001t= 2.002 ms
tolerances of my resistors are 20% so I assume you can round values if using silver or gold stripe(band) resistors.
Well, if this idea wont work then i will put arduino nano or micro and will forget about 555 forever :-))Mike why you were driving servo via fet instead of mosfet? Isnt it more efficient in this shcematic to use mosfet? Something like 2n7000?
Now i need to switch whole circuit from 3.3v 20ma gpio. Current consumption for the circuit with motor is approximately 550ma-560ma 5v.Any suggestions what transistor/mosfet to use?