That is for single supply!!! And again..
do not look at maximum ratings...useless for Operation
do not look at maximum ratings...useless for Operation
Can you please try and phrase the above differently. Very hard to understand the intended message
I think you are suggesting that I'm wrong, but I still don't think I am
I think you are suggesting that I'm wrong, but I still don't think I am
Maximum ratings are without Operation...no current at the Output, no Input Signal...etc.
Operation ist what we want
The difference at the Pin V+ and V - is Always 36 v.
It does Not Matter If 36 in V + and gnd at V-
Or
18 v at Pin V+ and -18V at Pin V -
Difference is Always 36 v.
That is the max at this opv.
Voltages is the Potential difference between two Points.
Operation ist what we want
The difference at the Pin V+ and V - is Always 36 v.
It does Not Matter If 36 in V + and gnd at V-
Or
18 v at Pin V+ and -18V at Pin V -
Difference is Always 36 v.
That is the max at this opv.
Voltages is the Potential difference between two Points.
last one....realistic 3_ with 31V rail and standard BJT transistors simulated! (not build and tested)
setup is 13,8dB gain, 5,6Vpeak input needed.
maximum swing is 27,414V peak...not bad for a opamp LT 1793 with +/- 15Vrail
kr
chris
setup is 13,8dB gain, 5,6Vpeak input needed.
maximum swing is 27,414V peak...not bad for a opamp LT 1793 with +/- 15Vrail
kr
chris
if you have a strong PSU and a huge heat sink you get:
27,414Vpeak --> about 19,38Vrms--> into 8R load is about 47WATT. in 4R it is 94WATT.
27,414Vpeak --> about 19,38Vrms--> into 8R load is about 47WATT. in 4R it is 94WATT.
Chris,
Have you check stability or square wave response with reactive load ?
And how about MOSFET dissipation at max load ?
Patrick
Have you check stability or square wave response with reactive load ?
And how about MOSFET dissipation at max load ?
Patrick
a bit serious calculation 😉
8R - class A configuration possible:
19,38Vrms / 8R--> requests a current of 2,4A - so bias setup of 1,2A should be sufficient.
peak 27,414V / 8R --> requests a current of 3,42Amps peak
per MOSFET dissipation is about 30V and 1,2 A---> 36WATT maximum.
4R - Class AB configuration needed
19,38Vrms / 4R--> requests a current of 4,85A - each current 2,43A
peak 27,414V / 4R --> requests a current of 6,85Amps peak -each current 3,43A
STOP -
with about 30V on the MOSFET and 2,43A we get 72,67WATT on the MOSFET!!!!
So, in summary: Much better to keep to the originally intended 24 or perhaps 25V rails.
It would still be very nice to use the bootstrapped opa828 up front. I'm not understanding why you're not getting a similar gain to the opa604 at ±24V rails
It would still be very nice to use the bootstrapped opa828 up front. I'm not understanding why you're not getting a similar gain to the opa604 at ±24V rails
e.g. 40W at 8R = 17,88Vrms ---> 17,88Vrms * 1,414 = 25,282Vpeak. That is the rail what you need....but...
with the sag of the PSU (high current is flowing) you have to add a sag of 4-7Volt.
lets take 5Volt.
so you needed DC voltage per rail is 30,282V---> 31Volt
so your transformer with 300VA and 24VAC should be right
24VAC after rectifier gives= 24VAC *1,414 (losses of diodes) = 31Volt
kr
chris
with the sag of the PSU (high current is flowing) you have to add a sag of 4-7Volt.
lets take 5Volt.
so you needed DC voltage per rail is 30,282V---> 31Volt
so your transformer with 300VA and 24VAC should be right
24VAC after rectifier gives= 24VAC *1,414 (losses of diodes) = 31Volt
kr
chris
Good...so with TO220 MOSFETs we have less Ciss at Vgs....i am interested in this kind of sound. 🙂