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Permanent 24 v to 12 v converter

Paul Osterberg
 

I’m surprised about the function of the Permanent 24 v to 12 v converter. If I understand it right the only original function is to keep the memory in the FM/AM radio even when the main switch is off.

The current when it is on is ca 0,5 volt, that is a lot of Ah during a day, or during a two-week crossing it’s close to 165Ah. That is a lot of waste unless you regularly run your gen set but we try to rely on solar.

The only way to turn it off is to pull out the fuse. To me that is overkill to have such a heavy-duty converter for such a little use.

 When my friend changes his car battery, he connects an ordinary 9 volt battery to the stereo and that is enough to keep the memory.

I have connected some 12 v appliances to the permanent converter, 12v led light in the galley, and a few USB outlets.

Have I missed anything about the function of the Permanent converter?

Paul on SY Kerpa SAM#259 Lagos

 

Paul,

I heard a humorous story about the "PERMANENT." Several owners of SMs, who knew Captain Amel well, complained about losing the memory in the AM/FM radio. Apparently they complained long enough and loud enough that Henri Amel did something about it and installed this PERMANENT 24-12 volt converter. It powers the AM/FM radio, 12 volt accessory receptacles and the Chain Counter. My understanding is that all were installed with an ON/OFF toggle switch (see photo below). Early SMs the switch was to the rear (1st photo), and later SMs the switch (2nd photo) was to the front. The Amel 54 also has a PERMANENT circuit (switch in 3rd photo).

The biggest problem with amp draw that I have seen is that this is the circuit that seems to always get overloaded as new 12 volt devices are added. I do not think that I have ever seen a SM that does not have some wiring added to the PERMANENT circuit. I believe if any SM is drawing more amps than it should on this circuit, that you will find something has been added.
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--
CW Bill Rouse Amel Yacht Owners School
Address: 720 Winnie, Galveston Island, Texas 77550 
   


On Mon, Oct 14, 2019 at 11:30 AM Paul Osterberg <osterberg.paul.l@...> wrote:

I’m surprised about the function of the Permanent 24 v to 12 v converter. If I understand it right the only original function is to keep the memory in the FM/AM radio even when the main switch is off.

The current when it is on is ca 0,5 volt, that is a lot of Ah during a day, or during a two-week crossing it’s close to 165Ah. That is a lot of waste unless you regularly run your gen set but we try to rely on solar.

The only way to turn it off is to pull out the fuse. To me that is overkill to have such a heavy-duty converter for such a little use.

 When my friend changes his car battery, he connects an ordinary 9 volt battery to the stereo and that is enough to keep the memory.

I have connected some 12 v appliances to the permanent converter, 12v led light in the galley, and a few USB outlets.

Have I missed anything about the function of the Permanent converter?

Paul on SY Kerpa SAM#259 Lagos

Paul Osterberg
 

Bill Thank you
I will add a switch not to concerned to loose my radio settings 
Paul

Thomas Peacock
 

As part of putting in new instruments, I was able to shut down the “permanent” Sailor. Unfortunately, we do not have an on/off switch anywhere on our Sailors.

When I installed a new Raymarine Autohelm, the main box has a 12 volt output for networking instruments that includes a power supply. Therefore, the various gauges and chart plotter all get power from that. One could consider having a backup power source for instruments, in case the autohelm were to go bad. The instruments are all activated by the Autohelm breaker. The new Quantum radar also is wired into that breaker, 24 volts. Thus, one Sailor is now freed up.
Since the VHF is the most important of my present 12 volt devices, it has its own dedicated Sailor.
The second Sailor runs the FM/CD radio, as well as the 12 volt circuits for cigar lighters. Since cigar lighter plugs and receptacles are finicky, we don’t use them anymore. Instead, I installed a 24 v to 5 v USB hub for phone and other small device charging. However, be aware that very new laptops may use the new USB 3/USB-C type connectors to charge the computer battery. It is important to be aware of the total demand on your USB hub.
The third Sailor is inactivated by having pulled the fuse. However, I sleep well at night knowing that in case either of the other two Sailors were to go down, there is at least a spare.

I don’t really care about the radio storing stations. But, if important, one could run the dedicated wire from the radio to the 12 v starter battery, with an in-line fuse. That is what is done on automobiles. The power draw is negligible. Plus you could always just pull the fuse if leaving unattended for more than a few weeks.

Tom Peacock
SM #240 Aletes
Chesapeake Bay, US, leaving for Martinique November 3


On Oct 14, 2019, at 12:30 PM, Paul Osterberg <osterberg.paul.l@...> wrote:

I’m surprised about the function of the Permanent 24 v to 12 v converter. If I understand it right the only original function is to keep the memory in the FM/AM radio even when the main switch is off.
The current when it is on is ca 0,5 volt, that is a lot of Ah during a day, or during a two-week crossing it’s close to 165Ah. That is a lot of waste unless you regularly run your gen set but we try to rely on solar.
The only way to turn it off is to pull out the fuse. To me that is overkill to have such a heavy-duty converter for such a little use.
 When my friend changes his car battery, he connects an ordinary 9 volt battery to the stereo and that is enough to keep the memory.
I have connected some 12 v appliances to the permanent converter, 12v led light in the galley, and a few USB outlets.
Have I missed anything about the function of the Permanent converter?
Paul on SY Kerpa SAM#259 Lagos