carpenter said:Wow, excellent report, and wonderful suggestions... so, with a hefty water cooled heatsink, I could up the bias from 200 mA to what value?
BTW, I think you're confusing 200mA for 200mV voltage drop over the source resistor.
Magura 🙂
Magura said:
BTW, I think you're confusing 200mA for 200mV voltage drop over the source resistor.
Magura 🙂
You're correct, Magura. I make this mistake more often than I care to admit.

I'll have to go back and reread Ed's post.🙂
So, P1 adjusts the bias by increasing (or decreasing) the voltage around the source resistor, correct?
carpenter said:So, P1 adjusts the bias by increasing (or decreasing) the voltage around the source resistor, correct?
"increasing (or decreasing) the voltage around the source resistor"
that's just consequence of bias changing , not root of
carpenter said:Gotcha... but P1 adjust this voltage up and down?
Well, you adjust the current, the voltage drop across the source resistors is just an easy wat of measuring the current.
Magura 🙂
carpenter said:Gotcha... but P1 adjust this voltage up and down?
(what you do on) water facet is responsible for amount of water flowing to the floor ........... yes
but how much your legs will be wet - really depends of fact how long your legs are......
source is gnd-ed ;
you put some voltage on drain ;
current flow through DS pipeline depends of voltage you put on gate .
all voltages respectively to gnd (source!!)
I keep referring back to my little ZV7 project. Nelson had a 0.5ohm resistor in the CCS. He runs 3 volts across it which yields 6 amps. Is this what I do to calculate the amperage available to the FETs in the F4?
I'll be back in an hour, or so.
Time to exercise my heart...🙂
I'll be back in an hour, or so.
Time to exercise my heart...🙂
now you're really making me wish I hadn't left the land of thermionics.......life was simple then, the girls were pretty, the mars bars were 6d each oh oh oh........
any way water reminds me of fish, fish remind me of flies, and flies remind me of steen with his fly open...oh choky stop it
any way water reminds me of fish, fish remind me of flies, and flies remind me of steen with his fly open...oh choky stop it
carpenter said:He runs 3 volts across it which yields 6 amps. Is this what I do to calculate the amperage available to the FETs in the F4?
Yes that's simply ohms law at work 😉
Magura 🙂
vitalstates said:now you're really making me wish I hadn't left the land of thermionics.......life was simple then, the girls were pretty, the mars bars were 6d each oh oh oh........
any way water reminds me of fish, fish remind me of flies, and flies remind me of steen with his fly open...oh choky stop it

wrong kind of water...thats exactly what I've got...
Hi Carpenter, sorry I missed the question before, its single ended input - single stereo amp...
try this, it seems to be well written ... http://www.kpsec.freeuk.com/voltage.htm
Regards
Ed
Hi Carpenter, sorry I missed the question before, its single ended input - single stereo amp...
try this, it seems to be well written ... http://www.kpsec.freeuk.com/voltage.htm
Regards
Ed
carpenter said:I keep referring back to my little ZV7 project. Nelson had a 0.5ohm resistor in the CCS. He runs 3 volts across it which yields 6 amps. Is this what I do to calculate the amperage available to the FETs in the F4?
Magura said:
Yes that's simply ohms law at work 😉
Magura 🙂
Perfect. Thanks Magura, and thanks Ed for the link.
So, with adequate heat removal, I can run 750mV bias.
750mV divided by 0.47 ohms = 1.6 amps per device.
1.6 amps times 0.47 ohms = 0.75 watts; so the stock 3 watt resistors are up to the task, correct?
Hope I'm doing this right....... shoot, amps times volts = watts. I did that last calc wrong.... should be amps squared times ohms which = 1.2 watts.
carpenter said:
Perfect. Thanks Magura, and thanks Ed for the link.
So, with adequate heat removal, I can run 750mV bias.
750mV divided by 0.47 ohms = 1.6 amps per device.
1.6 amps times 0.47 ohms = 0.75 watts; so the stock 3 watt resistors are up to the task, correct?
Hope I'm doing this right.......
You are running 1.6A bias, the 750mV is nothing but your way of measuring it.
Not quite right, but almost there.
1.6A multiplied by 0.47 ohms = 0.75V AKA 750mV
Current times voltage = power. 1.6A multiplied 0.75V = 1.2W
Magura 🙂
Magura said:
You are running 1.6A bias, the 750mV is nothing but your way of measuring it.
Not quite right, but almost there.
1.6A times by 0.47 ohms = 0.75V AKA 750mV sp current times voltage = power. 1.6A times 0.75V = 1.2W
Magura 🙂
You're quick!! 😀 😀 😀
carpenter said:
Perfect. Thanks Magura, and thanks Ed for the link.
So, with adequate heat removal, I can run 750mV bias.
750mV divided by 0.47 ohms = 1.6 amps per device.
1.6 amps times 0.47 ohms = 0.75 watts; so the stock 3 watt resistors are up to the task, correct?
Hope I'm doing this right....... shoot, amps times volts = watts. I did that last calc wrong....
P=I^2 x R
so P= 1,6^2 x 0,47= 1,2W ........... 3-watters still good
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