Just thought I would share my first encounter with class-d amplification.
This artichle is from 1986, from the now closed Danish magazin "Ny Elektronik" ...... so I've had it in my drawer for 20 years
It's unfortunatly in danish, but the diagram and component list is universal
We're talking about a total construction with only 5 transistors ....
5W from a single 12 VDC ... distortion .... not known .... switch freq 100 kHz
Maybe it could be adopted to some more power and split supply.
I know it isn't high end, but I think it's quite intriguing anyway
UcD = 14 transistors ....... this one 5!
http://home20.inet.tele.dk/audio/Class_D_Ny_Elektronik_1986.PDF
This artichle is from 1986, from the now closed Danish magazin "Ny Elektronik" ...... so I've had it in my drawer for 20 years
It's unfortunatly in danish, but the diagram and component list is universal
We're talking about a total construction with only 5 transistors ....
5W from a single 12 VDC ... distortion .... not known .... switch freq 100 kHz
Maybe it could be adopted to some more power and split supply.
I know it isn't high end, but I think it's quite intriguing anyway
UcD = 14 transistors ....... this one 5!
http://home20.inet.tele.dk/audio/Class_D_Ny_Elektronik_1986.PDF
BWRX said:A single 12V rail with a half bridge output stage will only give you 4.5W peak (2.25Wrms max) into 8ohms and 9W peak (4.5Wrms max) into 4ohms. And that's assuming a full output voltage swing and the output stage can provide enough current into those impedances.
Brian,
could you give me the maths here... I cant seem to remember WHERE I saved those equations.. also, how do you calculate power output with dual polarity supply (+/-)...
RX5
There is not that muct to read about the workings in the article.
I think you would need to simulate to get a better understanding and to find ways to improve. .... could be quite usefull to have a very simple desig for, say 20W .... would be enough to drive a small active speaker for the PC or something.
Then we'll of course also need a similar simple SMPS
There is not that muct to read about the workings in the article.
I think you would need to simulate to get a better understanding and to find ways to improve. .... could be quite usefull to have a very simple desig for, say 20W .... would be enough to drive a small active speaker for the PC or something.
Then we'll of course also need a similar simple SMPS
Baldin said:RX5
Thee is not that muct to read about the workings in the article.
I think you would need to simulate to get a better understanding and to find ways to improve. .... could be quite usefull to have a very simple desig for, say 20W .... would be enough to drive a small active speaker for the PC or something.
Then we'll of course also need a similar simple SMPS
hhhmmmmmm WHY didnt I think of it?? hahahaha sure would be nice to simulate and improve...
in a few days....
To calculate peak theoretical power output you just need to know the maximum output voltage across the load and the load impedance.
Peak power = (V^2)/R
RMS power = ((V/sqrt(2))^2)/R = (V^2)/(2*R)
For a single ended output the maximum theoretical output voltage is half of the total rail voltage. For a bridged output the maximum theoretical output voltage is the rail voltage.
Edit: Baldin beat me to it
Peak power = (V^2)/R
RMS power = ((V/sqrt(2))^2)/R = (V^2)/(2*R)
For a single ended output the maximum theoretical output voltage is half of the total rail voltage. For a bridged output the maximum theoretical output voltage is the rail voltage.
Edit: Baldin beat me to it
Baldin said:P = ((Vp/sqrt(2))^2) / R
So as Pafi says:
Vp = 12/2 = 6 V
P = ((6/1.414)^2)/8 = 2.25 W in 8 ohm
For a +- supply Vp equals the transformer voltage
ok got it... NOW I can sleep happy
thanks!!!!!!!!!!!!!!!!!!!!!!!!!!
BWRX said:To calculate peak theoretical power output you just need to know the maximum output voltage across the load and the load impedance.
Peak power = (V^2)/R
RMS power = ((V/sqrt(2))^2)/R = (V^2)/(2*R)
For a single ended output the maximum theoretical output voltage is half of the total rail voltage. For a bridged output the maximum theoretical output voltage is the rail voltage.
Edit: Baldin beat me to it
thanks!!!
I love furoms.. knowledge is POWER in RMS hehehe
need to sleeeeeeeeeeeeeeeeeeeep.... zzzzzzzzzzzzzzz
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