Hi , I have circuit generate sine and tringle wave have frequency between 100:4000 Hz with Vpp 5 volt.
I need circuit amplify these signals to be 80volt with max current 250 mA.
Thanks alot ?
If you feel confident, you can try this discrete design. This will give about 1 % THD at 4 KHz, so it is not hi-fi quality. As always, good construction and layout is necessary with T3/4/5 mounted on a decent heat-sink.
Frequency. Sine is relatively simple. But with triangle you need to go a compromise, because (according fourier series) it includes infinitely high frequency components.
Overall: I'd go for an audio amplifier. Usually 80Vpp output types can supply a lot more current, but there are many cheap, ready built circuits available.
If you want to use some kind of an audio amplifier, it must be capable to go down to near DC. Many audio amplifiers are only required to work down to 20 Hz, thus have capacitive input coupling.
Below the problem with having a restricted LF response can clearly be seen when amplifying a 100 Hz triangle wave. The DC coupled circuit has a THD of 0.4 % at 100 Hz, while the AC coupled circuit has a THD of 4.5 %.