DC TO AC INVERTERS

refer books on 'thyristor' by Willey

Other possibilities here

the best dc to ac inverter example that i know of is the gmac hybrid truck(not to be confused with a real hybrid refer:prius). it uses a mechanical magnetic engine to make dc to charge the baTTeries and make ac for 120vac or the batteries to make ac for 120vac, or the gas engine to turn the transmission to both make ac by turning the mechanical magnetic engine, or move the car forward(gas engine only). refer pulse dc magnetic engine.

I do not know your location. But you might try calling Torrance Electric in Cedar Rapids Iowa ask for Pat Davidson if he is still with them. Anyway, They deal with AC/DC Motor generators and Inverters as well anything you could imagine in the AC/DC Motor Field. Reliance being just one of their mfg. Companies. In all my years back (1985-1996) then dealing with them they never failed to find a solution and many times without charge. Though that may be due to the fact that we purchased or had them repair all our MG units and DC motors. Whats a phone call anyway if it will find your solution resolved?

Your question was very open ended, it should have included at least the following as a start:-

1) Maximum continous current available from your DC source.

2) DC Voltage

3) AC voltage

4) Maximum output wattage required.

Please remember that running normal car batteries down to less than 12.6 volts starts to severely reduce their life span. Leisure or deep discharge batteries should be used if it is envisaged that the batteries will be fairly empty at the end of their use....

Do not build a unit that supplies more watts than you need, it will flatten your battery even quicker.

Make sure that your design is very efficient, this will keep the battery in a better condition far longer.....free designs generally speaking do not achieve this....

Remember also that these units can kill, if you are not fully up to speed with live AC mains, this is NOT the place to start learning......

Andy,

While the gist of your response is accurate I would say that the battery industry has generally agreed that a discharge of 50% before a recharge to at least 80% of storage capacity for car batteries falls within their intended working limits. This equates generally to about 12 volts at 50%. Unless the batteries are constantly being charged, any use will immediately begin discharging below 12.6 volts and will immediately begin shortening their lives, however it's when you go below 50 % regularly that you can shorten battery life by years.

Its true, if you read the data put out by the battery companies themselves. It is why some batteries in cars fail within 3 years.....

Remember car batteries are designed to supply a big chunk of energy, quickly, therefore the plates are thin.

Leisure or deep discharge batteries are designed for longer life, have thicker plates, do not (in equivalent sizes) deliver energy quickly enough to start a car, but accept deep discharge better and have longer lives.

12.6 volts is the magic number whether you like it or not.....

You are not the first one to query that either, also you will probably not be the last.....

Remembering and using this info WILL prolong car battery life.....

I forgot to mention, the battery makers benefit when this advice is ignored......

I had a look round the web, some people feel that you can go down to 12.4 volts for a short time.

A good website is:- http://www.batteryuniversity.com/parttwo-35.htm

I found this on this site, it is good advice:- (but go and read the whole site for full infos)

Simple Guidelines

• Always store lead-acid in a charged condition. Never allow the open cell voltage to drop much below 2.10V. Apply a topping charge every six months or when recommended.
  
• Avoid repeated deep discharges. Charge more often. Use a larger battery to reduce the depth of discharge.
  
• Prevent sulfation and grid corrosion by choosing the correct charge and float voltages. If possible, allow a fully saturated charge of 14h.
  
• To reverse sulfation, raise the charge voltage above 2.40V/cell for a few hours.
• Avoid operating lead-acid at elevated ambient temperatures.
  
  Note: Wheelchair batteries don't last as long as golf cart batteries because of sulfation. The theory goes that a golf cart battery gets a full 14 hours charge whereas a wheelchair only gets 7 hours while the user sleeps.

There sort of things are available over-the-counter at boating- and caravan/trailer-accessory outlets, as well as by mail-order over the 'net. There is little need to design them.

You are SOOOOO RIGHT!!!

The self made one would still look self-made and probably be more expensive in parts cost alone as well as being less efficient.....and no guarantee either!!