28-09-2015, 04:22 PM
If anyone is interested, I recommend it's a good idea to learn about marine/boat engineering. I think the radio electronics also helps. There is plenty of work for boat electricians but it's a murky environment because very few marine electrical courses exist. So, you have a lot of household electricians wiring boats but the problem is this isn't such a good idea. They are likely to use domestic cable and, of course, DC and inverters need to be understood in depth.
Something I've been looking into over the last few days is alternator charging systems. I've noticed a large percentage of marine electrical people seem to view the positive and negative charging circuit as different. That is, current from the alternator + charging cable as opposed to the negative return. They figure if you put an ammeter in line with the B+ alternator you'll get the charging current but if you put the ammeter across the negative return to alternator case and battery, it will give the complete boat circuit amp draw. So I viewed it all the same as you would a radio:
Just like a transformer secondary, alternators produce AC voltage with is rectified by diodes. The alternator B+ ought to be the same as the DC ripple from a valve rectifier cathode used to rectify the secondary on a tube radio. Almost the same as with a radio, the alternator DC + goes to a lead acid battery bank (not a smoothing cap) but creates a charged supply. Current will of course be flowing through the charging cable and electron flow will leave the neg battery terminal, supply the boat circuit (pumps, DC lights) and return to the battery positive terminal (i.e. non conventional current flow).
I think it would be interesting for me to measure the amps from the B+ alternator and also the negative return to the alternator case but what I'd expect is for current to alter deeper into the circuit (the watts of appliances seem to me to be resistances in parallel.
Apparently it's now far more widespread to put ammeters in the negative charging line.
Inverters it seems have caused many problems with heavy currents.
Something I've been looking into over the last few days is alternator charging systems. I've noticed a large percentage of marine electrical people seem to view the positive and negative charging circuit as different. That is, current from the alternator + charging cable as opposed to the negative return. They figure if you put an ammeter in line with the B+ alternator you'll get the charging current but if you put the ammeter across the negative return to alternator case and battery, it will give the complete boat circuit amp draw. So I viewed it all the same as you would a radio:
Just like a transformer secondary, alternators produce AC voltage with is rectified by diodes. The alternator B+ ought to be the same as the DC ripple from a valve rectifier cathode used to rectify the secondary on a tube radio. Almost the same as with a radio, the alternator DC + goes to a lead acid battery bank (not a smoothing cap) but creates a charged supply. Current will of course be flowing through the charging cable and electron flow will leave the neg battery terminal, supply the boat circuit (pumps, DC lights) and return to the battery positive terminal (i.e. non conventional current flow).
I think it would be interesting for me to measure the amps from the B+ alternator and also the negative return to the alternator case but what I'd expect is for current to alter deeper into the circuit (the watts of appliances seem to me to be resistances in parallel.
Apparently it's now far more widespread to put ammeters in the negative charging line.
Inverters it seems have caused many problems with heavy currents.
