Exo
Active Member
This is a part of the scematic for a sattelite position system i'm desiging.
However I don't realy know how to calculate the required value for C6.
I'll try to expain first
It's part of a schort-circuit / overload protection. The resistors in chain R1 - R2 are calculated so they activate Q1 on a short circuit (+7.5A). This will cause the system to be deactivated immediately. No problem here...
But the second chain (R3 - R4) are for overload protection. (+2.5A) This signal needs to be delayed (by C6) so the system will not deactivate by the motors higher startup current...
First of all, does anyone know how long the startup of such an engine will take... It's rather hard to measure as the peak is already gone before the meter shows something...
then, Assuming Q2 is saturated and R13 - R14 are 10K each, what's the formula to calculate C6 to give a certain delay T...
However I don't realy know how to calculate the required value for C6.
I'll try to expain first
It's part of a schort-circuit / overload protection. The resistors in chain R1 - R2 are calculated so they activate Q1 on a short circuit (+7.5A). This will cause the system to be deactivated immediately. No problem here...
But the second chain (R3 - R4) are for overload protection. (+2.5A) This signal needs to be delayed (by C6) so the system will not deactivate by the motors higher startup current...
First of all, does anyone know how long the startup of such an engine will take... It's rather hard to measure as the peak is already gone before the meter shows something...
then, Assuming Q2 is saturated and R13 - R14 are 10K each, what's the formula to calculate C6 to give a certain delay T...