I need to create sixteen isolated power supplies on a single PCB. 

* Input voltage 9v DC.
* Output voltage 100v DC.
* Output current 10mA each.
* No precise regulation needed.
* Efficiency not terribly important.

I was thinking that maybe I could just wind my own transformer with one primary coil, and 16 secondary coils. Drive the primary coil with an H-Bridge, then use bridge rectifiers and capacitors to smooth the outputs.

* Does this sound sensible, or is there a better way to do it?
* Do I need a sinusoidal input waveform, or will a square wave do?
* Does it matter how many turns I use? Is more turns better? (As long as the ratio is correct)
* Does the frequency matter?

My cost and space budget are small, but negotiable. So I'd rather not just buy a whole load of off-the-shelf supplies.

Added: Schematic

![100v isolated supply](https://i.stack.imgur.com/rXWBF.png)