Using windlass resets the electronics

[Dieseldude]

Originally Posted by asinc

Run the windlass from your starting battery, keep the engine running while using the windlass and run the electronics from your house bank. Done

Seems like a good simple fix without expense and bother of extra equipment. Starting battery and alternator together should have enough capacity to run the windlass. The engine would normally be running for anchor ops anyway. Just would need to to some wiring to make this work.

[Uncle Bob]

Originally Posted by Dieseldude

Seems like a good simple fix without expense and bother of extra equipment. Starting battery and alternator together should have enough capacity to run the windlass. The engine would normally be running for anchor ops anyway. Just would need to to some wiring to make this work.

Exactly how mine has been for 10+ years, works really well and no misbehaving instrument problems. All the OP has to do is relocate the power connection to the start battery switch.

[Dieseldude]

Originally Posted by Dieseldude

Seems like a good simple fix without expense and bother of extra equipment. Starting battery and alternator together should have enough capacity to run the windlass. The engine would normally be running for anchor ops anyway. Just would need to to some wiring to make this work.

A thought on this fix: It is probably good for old basic diesel engines that have mechanical injection and no electronic controls. But with modern computerized engines, the transients from turning on and shutting off the windlass could cause problems with engine electronics.

[Dieseldude]

A common feature in electronic circuits is an inverse spike cancelling diode. These are often found connected to solenoid coils, often called spike suppression diodes. It is connected reverse polarity in the circuit. On a power supply such as an alternator output, it would have the cathode to positive and anode to negative or ground. Normally it will not conduct. It behaves as if it were not there. If a negative voltage such as a negative spike appears, it conducts the spike to ground. Problems with this arrangement are that the diode could burn for heavy spikes. This could be prevented by including a fuse in series with the diode. But if the negative voltage persists after blowing the fuse, the protection will be lost. If the main fuse for the alternator blows, then the protection will continue until that fuse is replaced. So the diode should be connected to the output side of the main fuse, not directly the alternator positive terminal. But the diode would need to be heavy duty with a current rating at least equal to the main fuse amp rating. Note that this would only protect from inverse or negative voltages, not positive over voltages.



This arrangement is also used to protect equipment from mistaken reverse polarity connection. Connect a piece of equipment backwards, and the diode shorts the wrongly polarized voltage to ground. The fuse for that circuit blows, and the equipment survives, provided that the diode conducts fast enough and the fuse blows fast enough.



Anyone out there have any thoughts on this ?

[LifePart2]

Well, problem solved.

I wired up all the navigation instruments to the starter battery instead of the house battery.

The starter is charged, and kept charged, from the house batteries which are charged by solar, wind and alternators.

When I start the engines there is still a voltage drop on the starter battery, yet this doesn't seem to bother the electronics.

When I run the windlass (still connected to the house batteries) the voltage drop does not get transmitted to the starter battery. Likewise it seems that any voltage spike also does not get transmitted, probably because the starter battery acts like a giant capacitor.

Net result is no more shutting down of my electronics when the windlass operates.

So now I am happy.

Thank you everyone for contributing your ideas.

[rwidman]

Originally Posted by LifePart2

When I operate the windlass, it resets (cuts and then restores power to) all my navigation instruments. Which is not good for them:
The raspberry pi may corrupt the SD card,
The Standard Horizon often does not reconnect the remote mic

Neither of these outcomes are ideal, and this occurs mostly when stopping the windlass, though it can also happen when starting it. When the chain is actually running, all is fine. I am presuming the inductive load coming on or off stream is spiking something, so how do I fix it?

We have a 300 AHr lithium battery pack. This connects directly to the windlass, and also powers the instruments. The Pi is powered through a DC voltage regulator that should provide a constant 5.25v, but clearly it cannot adapt fast enough.

I would have thought that the capacity of the lithium batteries would be big enough to smooth out the spikes, but clearly not.

Any suggestions?

Thanks

Yes. Connect your electronics to the starting battery, not the house battery (which I am assuming powers the windlass). If your windlass is connected to the starting battery, connect your electronics to the bouse battery.

If you want to get more complicated, you could use a diode and a large capacitor to stabilize the voltage to the electronics but if you knew how to do that you probably wouldn't have asked the question.