Hello,
I'm finally getting around to building an electric fishing Kontiki and have some questions about how to do so. First off an electric Kontiki is basically a timed torpedo with a prop either at the rear or more recently at under the front to take a line out past the breakers into deeper water where hopefully more and bigger fish lurk.
I have a schematic I've drawn up at
The trolling motor is a Mercury 12VDC/30Amp, 30lb thrust type. I have no other specs on it and the suppler couldn't provide any either. Other commercial Kontikis use the same motor, one brand with two
12V/7.2Ah SLA batteries and the other with two 12V/12Ah SLA batteries. I'm intending to use three 12V/7.2Ah batteries but my concern is that the motor will draw so much under load that the PIC will reset itself or just turn off the power supply relay. I do intend to disable Brown-out Reset on the PIC and have a huge cap on the PIC power supply to try and combat this. The motor is also connected to the PWM port of the PIC and using the power mosfet I can PWM the motor rather that just turning in on via a relay. This way I could possibly program it to go-hard to get through the breakers then slow down. Also I read something about using a zener diode across a mosfet and not just D5 but I'm not sure about what value zener to use.Basically I have a reed power switch to provide power to the PIC that in turn does some startup checks (battery level, leakage) then if OK switches on the power supply relay and checks the light level for the weak strobe. The time is set at a default of 0mins and the Timeset reed switch sets the time in 5min increments to a max of 25mins then back to zero. The Motor Start reed switch starts the motor but if the Timeset switch is activated while the motor is going then it stops the motor and adjusts the time. During operation the PIC runs battery level, leakage, light-level checks and once the set time is reached it stops the motor, activates the servo release mechanism to drop the line and shuts down by turning off the power supply relay. Naturally to use the release mechanism I have to have a second line to the Kontiki but there will be an alternate mounting point for single line use. If it's turned on and then needs to be turned off then setting the time to 0mins and trying to start the motor will shut it down. That or some other combination or maybe a timeout. Haven't decided yet.
I hope I've provided enough information, sorry if I haven't.
Any and all advice is greatly appreciated
Regards,
Rubicon.