high voltage output need

[franticEB]

Hi, i've to design a sort of amplifier that could perform an amplification of input signal digitally generated on local board.



My board is fed with 50 volts power supply.
I'm looking for ideas on how to proceed....i'd like to be able, if it is possible, to tune voltage and output current... tips, tutorials, application notes from which start for my project are accepted, as well as an outline of the principles to be followed.
Thanks

 

[barry]

What's your load? What frequency?

Some kind of push-pull circuit is what first springs to mind...

 

[Audioguru]

Many years ago electrostatic speakers were available (maybe some are still used today) and were driven from a high voltage amplifier.
The amplifier used an output transformer that stepped up the voltage. Look for the amplifier circuit in Google.

 

[franticEB]

the range of frequencies are indicated in the figure (20Hz-20Khz) and high voltage speakers could be the load...

 

[jiripolivka]

This task is easy for vacuum-tube amplifiers. They are good in high-output power applications, and power audio transformers can adjust the output AC voltage as needed.
Today, high-power amplifiers are preferably built with transistor and MOSFET technology. I am not sure if power audio transformers are still available.
Maybe you can check with some hi-fi audio specialists, vacuum-tube amplifiers and power transformers can still be found on e-bay.

 

[FvM]

Load impedance matters when deciding about amplifier technology and e.g. feasibility of an output transformer.

I am not sure if power audio transformers are still available.

I made most audio power transformers myself (or got them made in a workshop). Everybody who understands transformer basics can do that.

 

[chuckey]

As I see iit you have two alternatives, one is to step up your 50 V DC to 250 VDC and use class B power amplifier with high voltage transistors or step the 50 V up to 125 V and use a H bridge configuration amplifier, or as said just use a transformer to step up your 50V output from a class B amplifier to 250 V. Again if you use a H bridge configuration, you would get 100V p-p, so the "transformer" would be 100 :250 or 1:2.5.
Frank