I need to boost automotive voltage(12-14 volts) to 16 volts at 5 amps. Can someone point me to a good device to use for this? I've found a LM324 op-amp but I'm not sure if this is the right way to go.

 

Hello lektronics,

I'm sorry, but after long and careful consideration by the Board staff members, a decision was recently made to prohibit all discussions of motor vehicle related projects on this board.

This is due to the real safety hazards and potential legal issues that may be involved when people who were not specifically trained as automotive electrical engineers make recommendations for people who are not specifically trained and certified to build and install automotive-type projects.

The only recommendation that we can make is to have your motor vehicle professionally maintained just as it was originally configured when delivered by the dealer, as at that time it was in compliance with all safety, transportation department regulations and emissions laws.

This policy may sound a bit over-restrictive, but it was the only logical decision that could be arrived at. I am not a member of the staff here, but I wholeheartedly agree with their decision.

 

It's not an automotive project, I should have explained. I've got a
car alternator tied to a wind generator and I use output of the
alternator charge a backup battery. I'm using a board that requires
16 volts to charge the small battery.

 

Can be done if your alternator can supply about 8.3A @ 13V.

 

A wild thought: an alternator supplying two different battery banks via a diode OR gate adds another diode drop from rectifier to regulator so armature current is increased so output V is increased to compisate for OR diode drop; add a few diodes between your alternator and regulator to force output to 16 V ?? Diodes need to be about 5 A. Have not tried it myself.

 

The alternator will have an internal electronic module to regulate the voltage.

You could remove that and bring the field wire out, then use an external regulator module.

These are also a standard part, as many older / larger alternators have the regulator external.

If you use an external regulator, you can connect it's voltage sense wire directly at a battery so it forces the alternator to produce the correct voltage.

(Depending on the design of the existing regulator, you may just be able to disconnect it's sense wire and connect that externally to the battery).

 

A wild thought: an alternator supplying two different battery banks via a diode OR gate adds another diode drop from rectifier to regulator so armature current is increased so output V is increased to compisate for OR diode drop; add a few diodes between your alternator and regulator to force output to 16 V ?? Diodes need to be about 5 A. Have not tried it myself

I kinda get what you're saying but I'm a analog circuit newbie and
designing a circuit like this is way beyond my capabilities. I also need
around 13.5 volts for 1 set of batteries and 16 volts for my backup setup.

The alternator will have an internal electronic module to regulate
the voltage.

The alternator does not have an internal regulator, it
has an external. The problem is I need two outputs, the normal 13 to 14
volts to charge one set of batteries and the 16v line to charge the
backups. The board I'm using to switch from normal to backup batteries
on the fly requires 16 volts to start charging the backup batteries.

What I was thinking in some type of amplifier IC that would boost the
normal output for the main bank of batteries and feed the 16 volts to
the backup system so it would change the backup batteries.

 

What you need is either a DC-DC boost converter to bump the 13v-15v up to 16v, or modify the existing alternator's regulator to output 16v and use a "buck" regulator to get the voltage down to that required for the other batteries.