Can someone please explain to me how the four flyback diodes actually works? what will happen if no flyback diodes are not used? and why are Schottkey diodes prefared to be used?
Can someone please explain to me how the four flyback diodes actually works? what will happen if no flyback diodes are not used? and why are Schottkey diodes prefared to be used?
Thanks for the reply. Regarding the link below,are C1 and C2 in figure 7 used to smooth the input supply? and why in figure 7, C1 is 1000uF and in figure 8 C1 is only 22uF ?
Thanks for the reply. Regarding the link below,are C1 and C2 in figure 7 used to smooth the input supply? and why in figure 7, C1 is 1000uF and in figure 8 C1 is only 22uF ?
hi,
A good question.
The two circuits appear to have different authors, I would choose a cap to suit the motor size as well as the power supply source.
I would not use a 22uF, more like a 470uF or 1000uF and a 100nF in parallel.
Flyback diodes are not always required, it depends on the speed you'll be switching the motor at, as long as you're using mosfets there is an intrinsic diode built in, it only becomes a problem when the motor is switched at a frequency close to or inside the intrinsic diodes recovery time which will cause it to switch slowly increasing heating and possible latching up, this value is sometimes found on the PDF of FETs.
Schotkey diodes are preferred because their conduction voltage will be lower than that of the body diode.