The circuit below is a slot car racing controller with hall effect wiper and braking fet. I am trying to figure out a way to create braking at power off. I have tried two approaches with a normally energized relay. Both fail as the relay does not release while the motor is spinning!
All 3 relays I have tired are low coil current as I am trying to minimize the overall current draw. (a diode across the motor makes no difference!)
How would one wire a capacitor to hold power to the whole circuit for at least a second or two? Long enough to brake the motor? My efforts at that have failed as well. FYI the circuit draws at least 150 mA as it is. (30 hall switches at 3-4 mA each)
A mechanical switch would be a last resort. (more conductors to the handle and I'm trying to keep it all solid state)
all comments are appreciated
All 3 relays I have tired are low coil current as I am trying to minimize the overall current draw. (a diode across the motor makes no difference!)
How would one wire a capacitor to hold power to the whole circuit for at least a second or two? Long enough to brake the motor? My efforts at that have failed as well. FYI the circuit draws at least 150 mA as it is. (30 hall switches at 3-4 mA each)
A mechanical switch would be a last resort. (more conductors to the handle and I'm trying to keep it all solid state)
all comments are appreciated
Attachments
-
310.9 KB Views: 10