Am 09.08.2012 02:24, schrieb Dimitrios Tsifakis:
What is the VDC rating of the FKP1 caps in your 1 kW PA?
It is a mixture because i had only a few pieces on hand. If i remember
correctly the lowest DC voltage is 1.25 kV.
Output impedance is about 1.4 ohm. I have designed it to produce 50 W
at 12 V and of course 200 W at 24V.
Yes, good idea. In /p for moderate power and at home in QRO :-)
I work in multiples of 12 V as I
normally use big SLA batteries to power my equipment. The FET is a
monster IXYS 500V/55A FET which should be bombproof.
But you could have much lower on-resistances when using a 100V FET. 200W
at 24V is no problem though. IXYS is mostly a good choice. But quite
expensive. Once you lost a pair of them you begin to think to go back to
the IRFP types, at least i have done so ;-)
I do know that things are probably simpler if I select a higher
voltage supply as that will increase the output impedance and make
life a bit easier on the poor capacitors. But I do want to be able to
operate it out in the field and not carry half a truck worth of
batteries :-)
:-) I can fully understand that.
In my first Lf /p experiments i used this 1 kW PA and run it on 12V or
24V or 36V, using batteries in series. But it should be no problem to
get a good efficiency even at 12V DC, at least for a 100W PA.
In any case, I don't want to go more than 200 W as I am scared of the
voltage developed across my loading coil (currently about 12 mH or ~10
kohm XL).
73, Dimitris VK1SV/SV1DET
73, Stefan/DK7FC
| 