Here's what I am looking for:
A N channel power mosfet that is linear around 2A of Drain current and 40vdc supply voltage.
Bias voltage 2-4 volts or so.
will be running into a 64:8 Z transformer.
So far:
BUZ900P
2SK1529
2SK135
I think these are all lateral mosfets.
IS there an IR part that could work?
The attached image is of the output stage.
A N channel power mosfet that is linear around 2A of Drain current and 40vdc supply voltage.
Bias voltage 2-4 volts or so.
will be running into a 64:8 Z transformer.
So far:
BUZ900P
2SK1529
2SK135
I think these are all lateral mosfets.
IS there an IR part that could work?
The attached image is of the output stage.
Attachments
yeah....
yes i am.
simulates good with a p channel buffer mosfet driving the n-channel stage.
good for 12W RMS into 8 ohms.
power supply thinking of:
33V/5A transformer
100v/50A bridge rectifier
2 50v/10,000uf caps
2mH air core inductor
then 2 50v/10,000uf caps
per channel
The p-channel buffer will have its own pi filter taken from the above mentioned bridge.
comments?
yes i am.
simulates good with a p channel buffer mosfet driving the n-channel stage.
good for 12W RMS into 8 ohms.
power supply thinking of:
33V/5A transformer
100v/50A bridge rectifier
2 50v/10,000uf caps
2mH air core inductor
then 2 50v/10,000uf caps
per channel
The p-channel buffer will have its own pi filter taken from the above mentioned bridge.
comments?
The Exicon MOSFETs are nice. They do have datasheets on their website, although they contain limited data.
I have a spice model for ECF20N25 which you may find useful. Maybe not the exact one you're looking for, but they all behave similarly. Exicon will probably send you more data if you ask them.
I have a spice model for ECF20N25 which you may find useful. Maybe not the exact one you're looking for, but they all behave similarly. Exicon will probably send you more data if you ask them.
Code:
.SUBCKT ECF20N25 1 2 3
**********************************************
* Model Generated by PEDC *
*Copyright(c) Power Electronics Design Centre*
* All Rights Reserved *
* Power Electronics Design Centre *
* Dept of Elec & Electronic Engineering *
* University of Wales Swansea *
* Singleton Park *
* Swansea SA2 8PP *
* Tel : +44 (0)1792 295420 *
* Fax : +44 (0)1792 295686 *
* E-mail : [email]pedc@swansea.ac.uk[/email] *
**********************************************
* Model generated on Dec 9 1999
* MODEL FORMAT: SPICE Level 1
* External Node Designations
* Node 1 -> Drain
* Node 2 -> Gate
* Node 3 -> Source
*
*
*
* O [1]
* |
* Z
* Z Rd
* Z
* D2 |
* Cdg0 |\ || [9]
* |-||--| >|O---O-----|--------|
* | [4]|/ || | | |
* [2] Rg | ||---| Z --- __|__
* 0--/\/\/\/\-O----|| M1 Z / \D1 _____
* |[7] ||---| Z --- |Cds0
* | | Z | |
* | Cgs0 | |RDS | |
* |-----||--O---O-----|--------|
* | [8]
* |
* O
* |
* Z
* Z Rs
* Z
* |
* O [3]
M1 9 7 8 8 MM L=1 W=1
* Default values used in MM:
* With the exception of Cgs0 the capacitances are
* added externally
* Other default values are:
* RS=0 RD=0 LD=0 CBD=0 CBS=0 CGBO=0
.MODEL MM NMOS LEVEL=1 IS=1e-32 CGSO=1.57e-9
+VTO=0.414 LAMBDA=0.104 KP=2.808
RS 8 3 0.191
D1 8 9 MD
.MODEL MD D IS=1.0e-32 N=50 BV=250
+CJO=1.54e-9 VJ=0.633 M=0.479
RDS 8 9 1e+06
RD 9 1 0.289
RG 2 7 13.3
* Drain Source capacitance Cds0
CAP1 9 8 403e-12
*************************
* Gate Drain capacitance Cdg0
CAP 7 4 25.6e-12
*************************
* Gate Drain Capacitance Cdgj0
* Modelled as a diode
D2 4 9 MDD
.MODEL MDD D IS=1e-32 N=50
+CJO=137e-12 VJ=0.7 M=0.5
*************************
.ENDS
A Nemesis project seems fun, output transformers are a pretty good idea.
IR only has HEXFETS in ther line today, i think something like the IRFP240 would work well if You can use a TO 247 device, as i recall the BUZ 900 is TO3 ? As r-d/s is of lesser importance with the ot the Magnatec devices could be an option. Has been hailed as very good and, i think, still carries TO 3 parts.
buffer...
well... it will make driving it easier...
47K input impedance instead of 1K or so...
improves HF response etc...
also, by adjusting how much current i have through the P channel buffer... i may be able to have some distortion cancellation.
hmm... 3 12V batteries per channel.... at least 10A/h they are pretty large and expensive.
yes i have thought about it and have built a power follower (12v supply at 4.5A bias current)... best midrange i have EVER heard in a SS amp.
anyways....
should 33vac be enough for a 40v supply at 2A?
well... it will make driving it easier...
47K input impedance instead of 1K or so...
improves HF response etc...
also, by adjusting how much current i have through the P channel buffer... i may be able to have some distortion cancellation.
hmm... 3 12V batteries per channel.... at least 10A/h they are pretty large and expensive.
yes i have thought about it and have built a power follower (12v supply at 4.5A bias current)... best midrange i have EVER heard in a SS amp.
anyways....
should 33vac be enough for a 40v supply at 2A?
Re: buffer...
Yeah, some sources would definitely have a problem with that.
Apparently ElectraPrint is selling a "passive preamp" that uses a 1:8 step-up trasnformer with a 10k pot across its secondary. Has an input impedance of just 150 ohms. Don't know what source components they expect someone to drive that load with.
Aye.
Alas.
Yeah, I've had very good results with battery power so far and soon I hope to have my system completely off the grid soon.
It should as long as the transformer's around 100VA or so.
Good luck!
se
AudioGeek said:
Yeah, some sources would definitely have a problem with that.
Apparently ElectraPrint is selling a "passive preamp" that uses a 1:8 step-up trasnformer with a 10k pot across its secondary. Has an input impedance of just 150 ohms. Don't know what source components they expect someone to drive that load with.
Aye.
Alas.
Yeah, I've had very good results with battery power so far and soon I hope to have my system completely off the grid soon.
It should as long as the transformer's around 100VA or so.
Good luck!
se
heres what i got so far:
first a hammond 167T36 its a 36v/ 12A power transformer.. going to use this for both channels.
Then either a bridge rectifier or some discretes.. dunno which yet.
Then 2 50V / 10,000uf caps DK P6939-ND
Then a 6.8mH air core Solen with 1ohm DCR
Then 2 more of those caps.
this is per channel.
The input stage is powered by a LT317 with 40v input and 30v output at 40mA.
comments?
first a hammond 167T36 its a 36v/ 12A power transformer.. going to use this for both channels.
Then either a bridge rectifier or some discretes.. dunno which yet.
Then 2 50V / 10,000uf caps DK P6939-ND
Then a 6.8mH air core Solen with 1ohm DCR
Then 2 more of those caps.
this is per channel.
The input stage is powered by a LT317 with 40v input and 30v output at 40mA.
comments?
Came across some more Exicon models. No ECF10N16 though.
Code:
.SUBCKT ECF10N20 1 2 3
**********************************************
* Model Generated by PEDC *
*Copyright(c) Power Electronics Design Centre*
* All Rights Reserved *
* Power Electronics Design Centre *
* Dept of Elec & Electronic Engineering *
* University of Wales Swansea *
* Singleton Park *
* Swansea SA2 8PP *
* Tel : +44 (0)1792 295420 *
* Fax : +44 (0)1792 295686 *
* E-mail : [email]pedc@swansea.ac.uk[/email] *
**********************************************
* Model generated on Dec 6 1999
* MODEL FORMAT: SPICE Level 1
* External Node Designations
* Node 1 -> Drain
* Node 2 -> Gate
* Node 3 -> Source
*
*
*
* O [1]
* |
* Z
* Z Rd
* Z
* D2 |
* Cdg0 | \|| [9]
* |-||--| >|O---O-----|
* | | /|| | |
* [2] Rg | ||---| Z ---
* 0--/\/\/\/\-O----|| M1 Z / \D1
* |[7] ||---| Z ---
* | | Z |
* | Cgs0 | |RDS |
* |-----||--O---O-----|
* | [8]
* |
* O
* |
* Z
* Z Rs
* Z
* |
* O [3]
M1 9 7 8 8 MM L=1 W=1
* Default values used in MM:
* The capacitances are added externally
* Other default values are:
* RS=0 RD=0 LD=0 CBD=0 CBS=0 CGBO=0
.MODEL MM NMOS LEVEL=1 IS=1e-32
+VTO=0.635 LAMBDA=0.11 KP=2.376
RS 8 3 0.427
D1 8 9 MD
.MODEL MD D IS=1.0e-32 N=50 BV=250
+CJO=1.0e-9 VJ=0.7 M=0.5
RDS 8 9 1e+06
RD 9 1 0.62
RG 2 7 80
* Gate Source capacitance Cgs0
CAP1 7 8 480e-12
*************************
* Gate Drain capacitance Cdg0
CAP 7 4 12.2e-12
*************************
* Gate Drain Capacitance Cdgj0
* Modelled as a diode
D2 4 9 MDD
.MODEL MDD D IS=1e-32 N=50
+CJO=75.4e-12 VJ=0.174 M=1
*************************
.ENDS ECF10N20- Status
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