Chart Plotters for Dummies?
- Thread starter Bull City
- Start date
SASSAFRASS
Super Anarchist
Check the settings on the transducer, it may have a high and low Frequency, typically they are default to auto but you can select one or the other as well as the pulse frequency. Lower frequency will have less definition, which isn't a problem if you are only looking for the bottom. Ours used to error out when going astern from the prop wash, switching to the lower frequency and pulse rate helped.
Jim in Halifax
Super Anarchist
Yes. I told my (then) teen-aged daughter and friends not to turn on the inverter to power their boom box while sailing! Actually we seldom used the inverter except at anchor, so it wasn't a problem after we discovered what was messing with the depth sounder...
gptyk
Anarchist
I'm thinking you'll need more than ferrite beads - worth a try though.
Separate 12v source to plotter - isolate the grounds too.
If this solves it, you know that filtering power is the solution. Ferrite beads and possibly some big electrolytic caps on the 12v side.
If it doesn't, you know the problem is radiated. Physical shielding would be needed.
Separate 12v source to plotter - isolate the grounds too.
If this solves it, you know that filtering power is the solution. Ferrite beads and possibly some big electrolytic caps on the 12v side.
If it doesn't, you know the problem is radiated. Physical shielding would be needed.
Bull City
A fine fellow
- Thread starter
- #48
Yes, it does. TONIC is 27 feet LOA, and beam is 7.2 feet. Below is a diagram showing where some of the components are. There's a lot of wiring & cabling around the battery, pod drive, pod controller, and the On/Off switch.
The transducer data cable runs by the On/Off switch (which is mounted on a bunk riser) and plugs directly in to the EchoMap. Power for the EchoMap is hard wired into the 12V panel, which is mounted on the cabin bulkhead. The panel gets power from the 48V ePropulsion battery via a step-down.
The problem occurs when the pod drive runs. When the battery and On/Off switch are both On, the transducer is fine. Only when power is applied to the pod to make it run, even at very low speed, does the transducer signal stop.
It make me suspect the pod drive controller. Could ferrite beads on the controller cables be effective? I haven't tried that yet.
Panoramix
Super Anarchist
Most modern electric power supplies are "Switched mode power supply" which are basically fancy transistors switching on and off very rapidly the batteries. With all kind of trickeries, you can convert DC to AC, control the speed of a motor etc... Nevertheless they tend to create horrendous electromagnetic noises and I think that you are victim of this.
Your best bet is to shield from this noise by separating the cables, good grounding (you need to create a star) and may be ferrite beads on the motor cables that are close to the transducer cable.
Bull City
A fine fellow
- Thread starter
- #51
When I tried the alternate power source (LI portable power station, which is in the lower port-side cabinet, just aft of the bulkhead under the mast step), I was sitting on the V-berth with the EchoMap, and all the cables around me.
The only time it did not have the problem, was when we held the transducer over the side and under the water from the cockpit.
I tried ferrite beads on the EchoMap data and power cables: no help. I think I will try them on the motor cables.
Thanks to all, and I will report back.
SASSAFRASS
Super Anarchist
Might be worth looking at how things are grounded, if the plotter has a separate ground connection and is not connected to the drive try that, if it is connected try removing remove. The transducer lead probably has a shield ground connected to the plotter case in the plug. Not the DC negative but a case ground.
mckenzie.keith
Aspiring Anarchist
Here are my thoughts, for what it is worth. I am not super familiar with how the pod drive is set up so apologies if some of this doesn't apply.
Make sure the cabling between the pod drive (the electronic speed controller) and the motor is grounded properly at both ends. If there is no shield or ground, boo. They screwed up (in my opinion). It is best to have a ground wire or shield surrounding or bundled close with the power cables and terminated to the motor housing and the drive side ground or housing. If it is not like that, you can try doing that.
You can also try ferrite beads on the battery cables going to the pod drive controller and on the motor cables coming out of the controller. This can be instead of or in addition to any changes to the grounding wires. You can put all three motor drive wires through one big ferrite. If they are already bundled inside a single jacket that is fine. Just put the ferrite around the whole jacket.
You can probably put the plus and minus battery cables through one ferrite also (try it both ways... both wires through one ferrite, and each wire with its own ferrite). The ferrites will have to be large, probably.
You can also try putting ferrites on the depthsounder cabling near the depthsounder. Probably one ferrite on all cables, but you can try different configurations if you want.
The controller will be the source of all the noise. Not the motor itself (assuming it is a brushless motor, otherwise, if it has brushes, then the motor may be the noise source). Ferrites will likely work best if they are close to the noise source. If it is possible to adjust he switching frequency of the controller (sometimes called the carrier frequency) then that could help. Probably a harmonic of the controller is close to the ultrasound frequency of the depthsounder. So a small change could have a big effect. Most likely this is all sub 1 MHz stuff and so the ferrites will need to be large low-frequency ferrites. I doubt you are dealing with a radiated issue despite what others have said. But of course I could be wrong.
There may be someone posting in this thread who has spent more time debugging motor controller noise than me. But it is also possible that I am the resident expert. LOL.
I would also press the pod drive people for advice because they may have a solution for you and also because they should be made aware if they are not already that this can happen.
Bull City
A fine fellow
- Thread starter
- #54
@mckenzie.keith Thank you for those suggestions. I will follow up.
Panoramix
Super Anarchist
One thing not intuitive to look for is "ground loops".
Basically if you do a "loop" with ground cables, you have built an antenna ( called a "magnetic loop" ) and that will inject all kind of electrical signals to the grounds of your appliances which in turn will wreak havoc...
The good news is that you can solve this by having a single ground point (for instance your electric pod if there is an electrical connection to seawater) and to ground everything in a "star pattern" directly to the ground point.
The image below is for a pcb but you can apply the same principle :
Note how it is possible to have a single branch of your star dividing into 2 branches (PGND or AGND on the diagram)
If you start to think "too much grounding can't be bad" and ground the 2 ends of a wire, you will create ground loops everywhere...
Depending on your wiring it might be easy or not to fix....
Basically if you do a "loop" with ground cables, you have built an antenna ( called a "magnetic loop" ) and that will inject all kind of electrical signals to the grounds of your appliances which in turn will wreak havoc...
The good news is that you can solve this by having a single ground point (for instance your electric pod if there is an electrical connection to seawater) and to ground everything in a "star pattern" directly to the ground point.
The image below is for a pcb but you can apply the same principle :
Note how it is possible to have a single branch of your star dividing into 2 branches (PGND or AGND on the diagram)
If you start to think "too much grounding can't be bad" and ground the 2 ends of a wire, you will create ground loops everywhere...
Depending on your wiring it might be easy or not to fix....
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mckenzie.keith
Aspiring Anarchist
Everything can star from the battery. BUT, for mitigating interference, it is a best practice that there should be a "ground" going from the motor controller to the motor in addition to the three current carrying wires that actually drive the motor. This should be terminated to "ground" of the motor controller on the controller side, and the metal case of the motor (if it has a metal case) or to the stator core of the motor if that is the only option. If it makes you feel better, you could call it a shield instead of a ground. But this provides a return path for any harmonics or spikes caused by non-linearities or non-idealities of the motor and driver.One thing not intuitive to look for is "ground loops".
Basically if you do a "loop" with ground cables, you have built an antenna ( called a "magnetic loop" ) and that will inject all kind of electrical signals to the grounds of your appliances which in turn will wreak havoc...
The good news is that you can solve this by having a single ground point (for instance your electric pod if there is an electrical connection to seawater) and to ground everything in a "star pattern" directly to the ground point.
The image below is for a pcb but you can apply the same principle :
Note how it is possible to have a single branch of your star dividing into 2 branches (PGND or AGND on the diagram)
If you start to think "too much grounding can't be bad" and ground the 2 ends of a wire, you will create ground loops everywhere...
Depending on your wiring it might be easy or not to fix....
From what I can see of the epropulsion users manual there is no such shield or ground wire. An omission on their part as far as I can see. On the Pod Drive 1.0 Evo, it looks like there is just a battery connection, no phase wires. So on that model the controller must be integrated into the motor or hidden in the body of the unit somewhere.
The higher power models, from what I can tell, have three phase wires but no ground shield/drain wire. I am not sure I would try to add a wire. It could get kind of involved. But putting a ferrite over those three phase wires could be a good idea (as previously suggested).
On a PCB, you pretty much always want a solid ground plane if at all possible. That is going to be the lowest impedance path for return currents. Trying to mix the concepts of "star grounding" and "solid ground plane" by splitting up the ground plane will likely result in trouble. In some limited cases with designers who are very experienced, it could make sense to split a ground plane. But my advice to beginners is always don't do it.
Panoramix
Super Anarchist
I've learnt the hard way the effects of ground loops by doing exactly what you are describing (star ground with interconnected nodes) while putting together a ham radio station. Did not make sense to me until somebody told me "your ground system is a big antenna whereas it should be a stable reference"
IMHO for best RF behaviour and to provide a direct return you can link directly the ground of the motor controller to the motor's but only one side should go to the common ground point which does not have to be the battery. TBH something in electrical contact with seawater is probably a good bet as the ocean is a pretty good ground if not the best ground you can find on earth!
Most boat builders probably don't bother but a diesel engine is surely less onerous in terms of EMI.
Just my point of view, at least that is the first fix I would try... immediately after isolating the motor AC controller from the rest with ferrite on its power supply.
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Bull City
A fine fellow
- Thread starter
- #59
@Panoramix & @mckenzie.keith You are many levels above me. I will pass this on to the electrician who is helping me. BTW, he installed a ground wire from the pod drive to the keel.
I'm sorry, I'm really not sure. The orion takes in 11 to 17v iirc, and puts out a stable 12v (you can change this a bit too with the set screw) so maybe it would helpZora, I am having trouble with the fish-finder part of my Garmin EchoMap, and I'm wondering if some kind of voltage thingy might help. I am very ignorant about electricity. Here's the problem.
I am having a strange issue with the transducer. When I motor (ePropulsion pod drive) the depth reading starts to flash, and stops changing. It's fine when I'm sailing.
The Garmin unit gets power from the ePropulsion 48v battery, via a 48v->12v step down.
Garmin support suspect some type of electro-magnetic interference, and recommend adding a ferrite bead, and if that doesn't work, trying an alternate 12v power source.
I tried a veritable necklace of ferrite beads on the transducer/data cable and one on the power cable. Same thing: good depth signal until power applied to motor, then signal flashes. I have a portable power station on the boat which I tried, with the same result.
I have a marine electrician helping me, and we discussed the situation:
1) Since the transducer I am using is a "transom mount" and I am attempting to use it as an "in hull." It is mounted in a glob of wax from a toilet seal kit inside the hull
2) But what if this is not the problem? Suppose I went to the trouble and expense of installing the actual "in-hull" transducer, and the same damn thing happened? I'd be pissed. So would it make sense to install some type of voltage conditioner or electronic filter?
I have sent an email to the ePropulsion dealer, asking if they are aware of any similar cases. No response yet.
Do you or others have any ideas?
Thanks.
B.C.
