Electrónica Hacer caer el voltaje de salida 0,7v

[Kane]

Conviene tener en cuenta que los intentos de compensar con diodos la caída de tensión en los diodos del separador conducen indefectiblemente a una sobrecarga de las baterías, una de las razones por las que el separador de diodos no es la mejor solución para separar las baterías durante la carga.

If diodes really were a simple "one way valve for electricity" then, for many installations (not all), they would be an almost perfect solution to split charging multiple battery banks. However, real world diodes are not perfect "one way valves", they are anything but perfect .......
One of the side effects of diodes is that there is a voltage drop associated with them. This drop is not constant and varies from around 0.6 volts to 1.1 volts depending upon how much current is flowing through them. At very high charge currents the voltage drop can actually be as much as 1.6 volts. The higher the current, the higher the voltage drop. This means that the output voltage of your alternator at say 14 volts is not being presented to the batteries. The batteries will only be "seeing" between 12.9 and 13.4 volts depending upon the charge rate. Obviously this drastically reduces charging capability. The charge voltage on the batteries is simply too low.
Anyone who tells you that the voltage drop across a diode is fixed at 0.6 volts and does not change does not understand the subject and possibly read "beginners guide to electricity" and then stopped studying. Sorry, but that's the reality.
One solution is an external alternator regulator which senses the voltage at the battery instead of at the alternator (as per a normal alternator). This has the effect of compensating for the voltage drop across the diode by increasing the alternator output voltage.
Even this solution has it's problems. Firstly one has to decide which battery to sense. The domestic bank or the engine battery ? Let's put that to one side for the moment.....
Remember the voltage drop across the diode depends upon the current through it so the engine battery (which will usually be drawing much less current than the house bank) diode will have a lower voltage drop. Let's say it's 0.6 volts. The voltage drop across the diode to the domestic bank will be much higher (due to the higher charge current). Let's say it's 1.1 volt. We now have 0.5 volts difference between the battery terminal voltages.
Back to which bank to sense.... If the engine battery is sensed then we find that the domestic bank is being charged 0.5 volts too low. Obviously not what we are aiming for. If the Domestic bank is sensed we will find

that the engine battery is being charged 0.5 volts too high. This of course will damage the battery. There is no solution to this problem using diodes. The only way round the problem is to fit 2 alternators, one for each bank. This isn't always practical for mechanical or space reasons. It also isn't always something the boat owner can do him/herself, perhaps involving welding up brackets or other engineering techniques that they do not have access to. Obviously if it is possible then it's a reasonable workable solution


http://www.smartgauge.co.uk/diodes.html