Hi all.
I am fast approaching completion of my Aleph 2 amplifier, and would like comments regarding the usage of IRFP 140 devices.
I will be running about +40 to 45 vdc rail.
According to the data sheet, this should be OK.
My choice for this device is based on nothing more than having hundreds of these devices here ready to go. (Subject to matching).
Could someone please tell me if the usage of this device will be OK?
Kind regards.
George
I am fast approaching completion of my Aleph 2 amplifier, and would like comments regarding the usage of IRFP 140 devices.
I will be running about +40 to 45 vdc rail.
According to the data sheet, this should be OK.
My choice for this device is based on nothing more than having hundreds of these devices here ready to go. (Subject to matching).
Could someone please tell me if the usage of this device will be OK?
Kind regards.
George
I take this opportunity to ask what is the value of voltage drop across the resistor source dell'Aleph 2 ?
I have to make the test measurement on my aleph 2
thanks
I have to make the test measurement on my aleph 2
thanks
just go for it
consider decreasing gate resistors to 150-180R
observe stability
don't skimp on 1nF anti-oscillation caps
to vivanco - 500mV across 1R source resistors
consider decreasing gate resistors to 150-180R
observe stability
don't skimp on 1nF anti-oscillation caps
to vivanco - 500mV across 1R source resistors
ok perfect,,, you can also tell me what is the value of volts that must be measured at the ends of the source resistance (1 ohm) ... I ask because I measure an average of about 3.7 V
I already did - in post #3
3V7 is bloooooody too much!!!
something is wrong , not just setting
start new thread , put plenty of pictures and we can (hopefully) help
3V7 is bloooooody too much!!!
something is wrong , not just setting
start new thread , put plenty of pictures and we can (hopefully) help
1nF - whatever you find in drawer
start new thread , with pictures ;
without precise info , all we are doing is wasting fingertips
start new thread , with pictures ;
without precise info , all we are doing is wasting fingertips
Hi Zen Mod.
Thanks for your advice.
The circuit that you requested is exactly as shown in post 7.
Also the 1nf caps that I am using are Roderstien metalized polypropylene.
The source resistors are currently 221 ohm, and there is no problem in reducing them to 150 to 180 ohm.
What advantages do you see in reducing the value of the source resistors?
Kind regards
George.
Ps: here are some pics of the boards.
OK , pics still pending
140 is having slightly more capacitances than 240 , also greater xconductance , so Mueller effect resulting in harder (capacitive) load to preceding stage ...... means lesser/shorter bandwidth
to counteract that , decrease slightly gate resistors , observing stability
whatever , I think you're most probably good for.
........when you spend enough 140's in amp , rest you can send to OPLDF
140 is having slightly more capacitances than 240 , also greater xconductance , so Mueller effect resulting in harder (capacitive) load to preceding stage ...... means lesser/shorter bandwidth
to counteract that , decrease slightly gate resistors , observing stability
whatever , I think you're most probably good for.
........when you spend enough 140's in amp , rest you can send to OPLDF
I'm guessing that was a brain fart and you mean gate resistors.
Source resistors should be 1 ohm.
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