Thanks

John II

Also, I found out the hard way some time back what factors are the main cost drivers in PCB manufacture.  We had a backplane design that was 19"x5" and got prototypes (3 or 4 IIRC) that wound up costing about $55 each.  I called the PCB folks and asked them why they were so expensive and what I could do to bring the price down.  He said the odd size (19" long) required that they stop the manufacture in the middle of the process to rotate the material in the machine.  I redesigned it to shave 3" off and managed to cut the price by about 1/3.

The main cost drivers, most costly first, are (please correct any errors I may make here):

1. any manual operations (like that repositioning thing I mentioned)
2. Number of layers > 2
3. number of holes/vias
4. amount of material used.

You might talk to your PCB house and ask them what, if anything, you could do to lower the price.

Funny, the daughter boards that plugged into that backplane had to be redone.  The first batch were flawless per the design but for one little thing. The crappy old DOS-based Tango software I was using didn't have a pattern for a 68 pin PLCC socket in its library, so I very carefully, painstakingly created one... that was backward.  IOW, to make it work, I had to solder the socket on the 'wrong' side of the board.  Hard to hide that one; even a novice could see that it wasn't right.

Carpe Vigor

I wouldn't mind owning a couple of PWM boards and four or more output boards. I would need to know the cost of what that would be.

A couple of questions though. Have you tested it against difficult to run inductive loads yet ? (just currious)

Also my largest concern.

I'm going to be needing to run this off of a 120vdc battery bank (100vdc to 160vdc) Do you have any idea how hard it would be to build a DC to DC converter to provide the + - 170vdc ? I think that Hilo90mhz who is on this forum was building a DC to DC converter to ? Any thoughts on this would really be appreciated.

and this is the new hand made PWM board , man is tuff to do a double sided board with the laser printer method

More information, I would like to have, before I say yes, can you supply the basic schematic ?.

Can you define the protection circuitry ? For over current and for sudden drop of current at 80 % of full load capabilities.

What are the specifications of the Sine Wave Inverter ?.

Can you send the information directly ?>

Regards

I would like to send to you an article that shows the schematic, BOM of a DC/AC converter for you to read a for you to examine your design in reference to possible errors in your design.

As a retired electronic engineer, power was one of my disciplines and just reading the little info yu have supplied I see problems which are CRITICAL that need to be tested carefully.
I still do consulting engineering in power design --I have done from low AC generation ( 5 watts ) to high power ( 500 KW +)

Please connect with me directly, I am not trying to put you down at all, I am trying to offer you assistance to solve unforeseen future problems that only experience may give the solutions to them, I congratulate for your effort -- long and hard, as well as, difficult --

Points to ponder IRP360 is a 400 volts 24 amps Mosfet-- you are using it for +- 170 volts supply.
Not good -- you need 500 volts minimum -- I could give you a complete dissertation why.

+- 170 volts supply to generate 120 volts RMS or 170 Volts pick -- No overhead voltage for Mosfet saturation voltage and for choke current -- THINK why you need higher voltage, as a minimum you need +- 200 Volts -- the design should be for +- 220 Volts Peak DC, to allow for variations in the overall system, which forces you now to a new type of MosFets ( 500 Volts minimum).

There are many other things to ponder, like energy dumping at max power, temperature behavior, current protection for single AC source and for double AC source like yours, PCB and card cages, etc and more etc's.

Regards

Nando