If I understand correctly, the purpose (or benefit) of adding a capacitor would be to have a "seamless" transition when I switch power sources (vehicle/battery). This would mean that if there was music playing through the amp, then it would continuously play whenever the power source would switch (vehicle/battery). Is that correct? If this is the correct understanding about the capacitor, then I don't think I need it because I don't care whether or not the music has a "seamless" transition when I switch power sources. It is OK if it stops playing for some amount of time when the switchover takes place and then begins playing again after some amount of time.
The point of switching power sources for me is several fold. A little of the rationale is in this post:
https://diysolarforum.com/threads/a...ce-vehicle-vs-house-battery.74877/post-949733 . The gist of it is that I want to NOT have it hooked to ONLY my car battery so that I can use my amplifier when my car is off and not worry about draining my car battery. On top of that, I'd like to use the amps from my alternator when the car is running as opposed to using the amps from my house battery, since the house battery capacity is reserved for when the vehicle is off.
>> Sure, you've got some losses powering it through 2 DCDCs, but swapping input power while the amp is operating, doesn't seem like it would be >> healthy for the internals of the amp. In my opinion, I'd take the hit in efficiency vs the possible equipment damage.
Apologies, I tried to simplify my problem/question when I originally posted so that it would be easier for others to understand the main issue I was trying to solve. I will explain a bit more about the bigger issue that exists if I get rid of the relay switching idea and ONLY hook up the amplifier through the house battery system (which is being charged by the alternator when the vehicle is running, and hence still performs the "switching" power sources mechanism....
My 12v to 24V DC/DC Isolated Converter is 15 Amps. That means it produces 15 Amps @24V. If we ignore inefficiencies, this comes out to 30 Amps @12V. So this device will draw 30 amps from the alternator to charge the house battery. If I hook up my amplifier (which needs a 40 Amp fuse - but just for sake of understanding we'll assume it normally draws 20 amps) solely to the house battery (through the 24V to 12V DC/DC converter) then 20 amps @12V would be used by the amplifier, this is 10 amps @24V. These 10amps are coming from the house battery. So the alternator is supplying 15 amps (@24V) to the house battery, and the amplifier is drawing 10 amps (@24V) from the house battery. This means the effective charge from the alternator to the house battery is ONLY 5 amps (@24V). In this scenario the tax on the alternator is ONLY 30 amps (@12V) (again assuming we ignore inefficiencies, I understand that more will be drawn in order for the DC/DC converter to produce its output).
If instead, I am able to hook up the system I proposed above (using the single 5 pin relay), then I would have an effective charge rate from the alternator to the house battery of 15 amps (@24V) AND the alternator would have a 20 amp draw (@12V) from the amplifier, thus making the total tax on the alternator 30 amps (@12V) + 20 amps (@12V) = 50 amps. This way, I would use more amperage from my alternator but I wouldn't sacrifice any of my house battery charging. I believe I am far from my alternator's max potential, so I don't believe this will be putting any strain on the alternator.
Even if my guess at the amplifier's current draw is incorrect, the point is still the same (unless my understanding is incorrect somewhere, please correct me if so), thus I don't want to sacrifice my alternator to house battery charging capabilities if I can avoid it.
All of that said. If the 'power source switch over' is going to cause an issue (or potentially damage) the amplifier, then I'd rather not have that happen. So I am curious if I can still keep the gist of the automatic power source switching mechanism whilst addressing the amplifier damage issue? My amplifier has the ability to turn on via 3 different methods: (1) - Remote Wire (12V = ON, 0V = OFF), (2) DC offset on the RCA input (basically detecting whether there is an audio signal coming into the amplifier), and (3) - Full audio signal on the RCA input (more thorough check on the signal coming in, but this has a 30 second delay before turning off the amp).
I think (1) sounds promising in terms of safely turning off the amplifier before the switch over happens. I am just not sure what the right mechanisms would need to be to make this happen. As far as switching from the alternator to the house battery source, I could use the ignition wire to notify the amplifier to turn off. I would need to find a different (delayed) trigger for the relay however. I guess I could use a microcontroller in conjunction with the 5 pin relay. Instead of the ignition wire going into the relay, it would go into the microcontroller. Then the microcontroller can correctly turn on/off the amplifier when necessary and then send the trigger signal to the relay when necessary. The microcontroller is already tied to the radio system, so it can control when audio output is being sent to the amplifier.
I am thinking something along the lines of...when the ignition is sensed, block audio output from the radio, send the off signal to the remote wire of the amplifier, trigger the relay to perform the switch over (from house to vehicle), send the on signal to the remote wire of the amplifier, allow audio output from the radio. Then the opposite when the ignition is shut off... block audio output from the radio, send the off signal to the remote wire of the amplifier, trigger the relay to perform the switch over (from vehicle to house), send the on signal to the remote wire of the amplifier, allow audio output from the radio.
Maybe I am missing something or theres an easier way to achieve this so let me know if either or both are the case. Thanks for all the info so far.
