Register to reply

Power conversion logic. What am I missing?

by MachX
Tags: conversion, logic, missing, power
Share this thread:
MachX
#1
Mar7-13, 11:57 AM
P: 26
Hello,

I have a project that involves the coupling of a 12V Alternator with a small engine to power a loaded 12V battery.

The gas engine is 1.4HP (1043.979Watts) coupled to a 40 Amp 12V alternator which is charging a 12V battery under a 35 Amp load.

The way I see it, the 35 amp load @ 12V = 420 Watts = roughly 0.563HP. Giving the engine an advantage of 623.979 Watts greater than the required draw.

What I do not know is; what the RPM of the alternator is at is most efficient speed. However I am almost positive the engine can meet and exceed it.

Given a basic look at this, do these numbers seem to make enough sense to provide sufficient power for the system to continually work under load? Should I go with a 60A alternator instead? I know there will be losses due to mechanical inefficiency/friction But do these figures seem proportionate enough to actually put to use? What should I look out for?

Any advice greatly appreciated
Phys.Org News Partner Engineering news on Phys.org
Tricorder XPRIZE: 10 teams advance in global competition to develop consumer-focused diagnostic device
Study shows local seismic isolation and damping methods provide optimal protection for essential computing equipment
New filter technology uses inert gas to bore holes in high-quality steel
etudiant
#2
Mar8-13, 07:25 AM
PF Gold
P: 866
You are asking a relevant question which has no simple answer afaik.
Generator sets are usually built as an integrated unit, with gasoline motor and alternator tuned to get the desired performance. Your setup should work as is, simply because you do not have any big starting loads such as compressor motors or pumps and it is amply sized for the steady state load. Hopefully you have provisions to avoid frying the battery by overcharging it.
However, the efficiency is indeterminate. It may be close to or far from optimal and only experiment will tell.
timthereaper
#3
Mar8-13, 02:14 PM
P: 343
Yeah, you'll have to benchmark it. There's no easy answer to this.


Register to reply

Related Discussions
DC-DC power conversion and voltage regulators Electrical Engineering 5
Kinetic to Electric Power Conversion General Physics 24
DC to AC conversion and power relation Electrical Engineering 16
Pneumatic Power Conversion Mechanical Engineering 3
Base conversion - the LOGIC and INTUITION behind it... Electrical Engineering 2