Spec summary
Drive a pump with a running current of 1.3 amps at 24 volts.
Run and not run time is adjustable
Pumps are
on in pairs. Total of 4.
Bulk supply is 24 volts at 15 amps with small adjustment range. (20.8 to 24????) Post 115
Soft start in the order of a few ms. Post 167 This is probably the start time of the controller switcher.
On for 30 seconds, off for ~ 5 - 10 seconds. #178
Reset switch on failure instead of fuse #178
#229 6 hours run time 6 hours off time.
Flick or short pulse on to keep fish away from the pumps that are off.# 270 ability to reduce flow.
# 692 auto reset on failure.
Locked rotor protection.
Methods and drawbacks:
Basic switch. No locked rotor protection
Linear regulator - Initial Current limit set only by IC spec. Does not completely shut down on failure (1.25 volts) Repeated retries would probably result in thermal shut down.
Voltage adjustable
OEM controller modification:
Advertized as unreliable.
Initial current limit set by IC spec.
Starting Current limit not adjustable.
Voltage adjustable
Current limited FET switch.
Voltage not adjustable
Thermal problems on auto retry.
LT1074 Switcher
More robust than OEM IC.
Adustable current limit for initial start up
Adjustable voltage
More dificult to build on a proto board - but meets all requirements (I think)