High Power TL432?...

[Ed Lee]

On Friday, August 26, 2022 at 12:11:26 PM UTC-7, erichp...@hotmail.com wrote:

On 26/08/2022 02:08, Ed Lee wrote:
On Thursday, August 25, 2022 at 5:49:01 PM UTC-7, legg wrote:
On Thu, 25 Aug 2022 15:35:53 +0100, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 25/08/2022 14:49, Ed Lee wrote:
I am looking for 3x to 5x power output of typical TL432 (100mA). Is
there a higher power equivalent part? If not, i will probably put 3
to 5 of them in parallel.

What\'s wrong with the application note for using a higher current pass
transistor as a series regulator? App note 10.3 fig 10-5 in my copy.
How much current do you want to shunt at what voltage?

RL

12V 200W

I am thinking about either Tarlington or Qarlington.

Part Package Vbe Ib Ic Power
TL431 SOT-23 --- --- 0.05A 1/4W

Tarlington (3 stages)
PZT2907A SOT-223 5V 0.015A 0.8A 1W
2N6287 TO-3 5V 0.5A 20A 160W

Qarlington (4 stages, 2x Darlington)
MJD117 DPAK 5V 0.05A 2A 10W
MJ11011 TO-3 5V 1A 30A 200W
For how many milliseconds will the power transistor be dissipating 200W?

several minutes.

No realistic heatsinking can handle that dissipation in a single TO-3
package - if the application calls for that power over any extended
period you will need multiple paralleled power devices (with emitter
ballast resistors to share the current).

Yes, there will be power resistors to share the heat. I pick TO-3 mainly for the higher currents: 20A for 2N6287 and 30A for MJ11011.

 

[server]

On Fri, 26 Aug 2022 12:43:10 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:

On Friday, August 26, 2022 at 12:11:26 PM UTC-7, erichp...@hotmail.com wrote:
On 26/08/2022 02:08, Ed Lee wrote:
On Thursday, August 25, 2022 at 5:49:01 PM UTC-7, legg wrote:
On Thu, 25 Aug 2022 15:35:53 +0100, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 25/08/2022 14:49, Ed Lee wrote:
I am looking for 3x to 5x power output of typical TL432 (100mA). Is
there a higher power equivalent part? If not, i will probably put 3
to 5 of them in parallel.

What\'s wrong with the application note for using a higher current pass
transistor as a series regulator? App note 10.3 fig 10-5 in my copy.
How much current do you want to shunt at what voltage?

RL

12V 200W

I am thinking about either Tarlington or Qarlington.

Part Package Vbe Ib Ic Power
TL431 SOT-23 --- --- 0.05A 1/4W

Tarlington (3 stages)
PZT2907A SOT-223 5V 0.015A 0.8A 1W
2N6287 TO-3 5V 0.5A 20A 160W

Qarlington (4 stages, 2x Darlington)
MJD117 DPAK 5V 0.05A 2A 10W
MJ11011 TO-3 5V 1A 30A 200W
For how many milliseconds will the power transistor be dissipating 200W?

several minutes.

No realistic heatsinking can handle that dissipation in a single TO-3
package - if the application calls for that power over any extended
period you will need multiple paralleled power devices (with emitter
ballast resistors to share the current).

Yes, there will be power resistors to share the heat. I pick TO-3 mainly for the higher currents: 20A for 2N6287 and 30A for MJ11011.

Maybe you can PWM, or just bang-bang, resistors to ground.

Resistors can get very hot and don\'t have second breakdown.

 

[Ed Lee]

On Friday, August 26, 2022 at 1:38:07 PM UTC-7, jla...@highlandsniptechnology.com wrote:

On Fri, 26 Aug 2022 12:43:10 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:

On Friday, August 26, 2022 at 12:11:26 PM UTC-7, erichp...@hotmail.com wrote:
On 26/08/2022 02:08, Ed Lee wrote:
On Thursday, August 25, 2022 at 5:49:01 PM UTC-7, legg wrote:
On Thu, 25 Aug 2022 15:35:53 +0100, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 25/08/2022 14:49, Ed Lee wrote:
I am looking for 3x to 5x power output of typical TL432 (100mA). Is
there a higher power equivalent part? If not, i will probably put 3
to 5 of them in parallel.

What\'s wrong with the application note for using a higher current pass
transistor as a series regulator? App note 10.3 fig 10-5 in my copy.
How much current do you want to shunt at what voltage?

RL

12V 200W

I am thinking about either Tarlington or Qarlington.

Part Package Vbe Ib Ic Power
TL431 SOT-23 --- --- 0.05A 1/4W

Tarlington (3 stages)
PZT2907A SOT-223 5V 0.015A 0.8A 1W
2N6287 TO-3 5V 0.5A 20A 160W

Qarlington (4 stages, 2x Darlington)
MJD117 DPAK 5V 0.05A 2A 10W
MJ11011 TO-3 5V 1A 30A 200W
For how many milliseconds will the power transistor be dissipating 200W?

several minutes.

No realistic heatsinking can handle that dissipation in a single TO-3
package - if the application calls for that power over any extended
period you will need multiple paralleled power devices (with emitter
ballast resistors to share the current).

Yes, there will be power resistors to share the heat. I pick TO-3 mainly for the higher currents: 20A for 2N6287 and 30A for MJ11011.
Maybe you can PWM, or just bang-bang, resistors to ground.

Resistors can get very hot and don\'t have second breakdown.

Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.

 

[server]

On Fri, 26 Aug 2022 13:43:29 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:

On Friday, August 26, 2022 at 1:38:07 PM UTC-7, jla...@highlandsniptechnology.com wrote:
On Fri, 26 Aug 2022 12:43:10 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:

On Friday, August 26, 2022 at 12:11:26 PM UTC-7, erichp...@hotmail.com wrote:
On 26/08/2022 02:08, Ed Lee wrote:
On Thursday, August 25, 2022 at 5:49:01 PM UTC-7, legg wrote:
On Thu, 25 Aug 2022 15:35:53 +0100, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 25/08/2022 14:49, Ed Lee wrote:
I am looking for 3x to 5x power output of typical TL432 (100mA). Is
there a higher power equivalent part? If not, i will probably put 3
to 5 of them in parallel.

What\'s wrong with the application note for using a higher current pass
transistor as a series regulator? App note 10.3 fig 10-5 in my copy.
How much current do you want to shunt at what voltage?

RL

12V 200W

I am thinking about either Tarlington or Qarlington.

Part Package Vbe Ib Ic Power
TL431 SOT-23 --- --- 0.05A 1/4W

Tarlington (3 stages)
PZT2907A SOT-223 5V 0.015A 0.8A 1W
2N6287 TO-3 5V 0.5A 20A 160W

Qarlington (4 stages, 2x Darlington)
MJD117 DPAK 5V 0.05A 2A 10W
MJ11011 TO-3 5V 1A 30A 200W
For how many milliseconds will the power transistor be dissipating 200W?

several minutes.

No realistic heatsinking can handle that dissipation in a single TO-3
package - if the application calls for that power over any extended
period you will need multiple paralleled power devices (with emitter
ballast resistors to share the current).

Yes, there will be power resistors to share the heat. I pick TO-3 mainly for the higher currents: 20A for 2N6287 and 30A for MJ11011.
Maybe you can PWM, or just bang-bang, resistors to ground.

Resistors can get very hot and don\'t have second breakdown.

Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.

I often add a resistor on the input side of a linear regulator, to
gobble up maybe half the max dissipation.

 

[Jan Panteltje]

On a sunny day (Fri, 26 Aug 2022 13:43:29 -0700 (PDT)) it happened Ed Lee
<edward.ming.lee@gmail.com> wrote in
<37b51a00-b5d7-447b-8950-6b7ecd78bae2n@googlegroups.com>:

>Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.

Why not use a reverse converter to feed back power to the source?


Anyways, in the old days as over-voltage protection : voltage sensor driving a thyristor to short the output
and primary fuse.
That was the classic protection against the series switching transistor failing.

 

[Ed Lee]

On Friday, August 26, 2022 at 11:24:19 PM UTC-7, Jan Panteltje wrote:

On a sunny day (Fri, 26 Aug 2022 13:43:29 -0700 (PDT)) it happened Ed Lee
edward....@gmail.com> wrote in
37b51a00-b5d7-447b...@googlegroups.com>:
Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.
Why not use a reverse converter to feed back power to the source?

Same problem as lacking storage for Nat. Gas in another thread. For example, Russia is burning million dollars worth of Nat. Gas daily near the Finland border, because they have nowhere to store it. BTW, they also burn rubles for us to see by pumping to the west rather than burning at the source.

The power sources are 180Wh to 210Wh (300Wh when new) batteries. We need to remove energy from it, cannot pump it back. I am just burning a few cents.

;-(

Anyways, in the old days as over-voltage protection : voltage sensor driving a thyristor to short the output
and primary fuse.

We don\'t want to short the power source and explode.

> That was the classic protection against the series switching transistor failing.

The 200W Tarlington and 300W Qarlington are over-speced to avoid failure. In reality, i don\'t expect over 100W.

 

[Anthony William Sloman]

On Saturday, August 27, 2022 at 11:43:17 PM UTC+10, Ed Lee wrote:

On Friday, August 26, 2022 at 11:24:19 PM UTC-7, Jan Panteltje wrote:
On a sunny day (Fri, 26 Aug 2022 13:43:29 -0700 (PDT)) it happened Ed Lee
edward....@gmail.com> wrote in
37b51a00-b5d7-447b...@googlegroups.com>:
Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.
Why not use a reverse converter to feed back power to the source?
Same problem as lacking storage for Nat. Gas in another thread. For example, Russia is burning million dollars worth of Nat. Gas daily near the Finland border, because they have nowhere to store it. BTW, they also burn rubles for us to see by pumping to the west rather than burning at the source.

The power sources are 180Wh to 210Wh (300Wh when new) batteries. We need to remove energy from it, cannot pump it back. I am just burning a few cents.


;-(
Anyways, in the old days as over-voltage protection : voltage sensor driving a thyristor to short the output
and primary fuse.
We don\'t want to short the power source and explode.
That was the classic protection against the series switching transistor failing.

The 200W Tarlington and 300W Qarlington are over-speced to avoid failure. In reality, i don\'t expect over 100W.

The power spec on the part assumes an infinite heat sink - on real heat sinks they get hot enough to fail at lower power dissipations.

You have to add up the thermal resistances from junction to case, from case to heat sink, and from heat sink to ambient, work out your maximum ambient temperature and make sure that the junction never gets too hot. With big transistors you find yourself stuck with big heat sinks and a fan built into the heat sink assembly. It gets nasty. Even nastier when it\'s an afterthought, and there\'s no room for a big enough heat sink let alone the fan, as happens when you have to rescue other people\'s half-baked or over-hasty design efforts.

--
Bill Sloman, Sydney

 

[Ed Lee]

On Saturday, August 27, 2022 at 8:17:48 AM UTC-7, bill....@ieee.org wrote:

On Saturday, August 27, 2022 at 11:43:17 PM UTC+10, Ed Lee wrote:
On Friday, August 26, 2022 at 11:24:19 PM UTC-7, Jan Panteltje wrote:
On a sunny day (Fri, 26 Aug 2022 13:43:29 -0700 (PDT)) it happened Ed Lee
edward....@gmail.com> wrote in
37b51a00-b5d7-447b...@googlegroups.com>:
Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.
Why not use a reverse converter to feed back power to the source?
Same problem as lacking storage for Nat. Gas in another thread. For example, Russia is burning million dollars worth of Nat. Gas daily near the Finland border, because they have nowhere to store it. BTW, they also burn rubles for us to see by pumping to the west rather than burning at the source..

The power sources are 180Wh to 210Wh (300Wh when new) batteries. We need to remove energy from it, cannot pump it back. I am just burning a few cents.


;-(
Anyways, in the old days as over-voltage protection : voltage sensor driving a thyristor to short the output
and primary fuse.
We don\'t want to short the power source and explode.
That was the classic protection against the series switching transistor failing.

The 200W Tarlington and 300W Qarlington are over-speced to avoid failure. In reality, i don\'t expect over 100W.
The power spec on the part assumes an infinite heat sink - on real heat sinks they get hot enough to fail at lower power dissipations.

I figure around 1/2 for the transistor and 1/2 for the resistor. TO-3 is rated for around 100W at 200C (0.6 W/C) with reasonable heat sink.

 

[Ed Lee]

On Saturday, August 27, 2022 at 8:25:22 AM UTC-7, Ed Lee wrote:

On Saturday, August 27, 2022 at 8:17:48 AM UTC-7, bill....@ieee.org wrote:
On Saturday, August 27, 2022 at 11:43:17 PM UTC+10, Ed Lee wrote:
On Friday, August 26, 2022 at 11:24:19 PM UTC-7, Jan Panteltje wrote:
On a sunny day (Fri, 26 Aug 2022 13:43:29 -0700 (PDT)) it happened Ed Lee
edward....@gmail.com> wrote in
37b51a00-b5d7-447b...@googlegroups.com>:
Why not just constant current to resistors? The power transistors can handle the current, if i keep Vec low.
Why not use a reverse converter to feed back power to the source?
Same problem as lacking storage for Nat. Gas in another thread. For example, Russia is burning million dollars worth of Nat. Gas daily near the Finland border, because they have nowhere to store it. BTW, they also burn rubles for us to see by pumping to the west rather than burning at the source.

The power sources are 180Wh to 210Wh (300Wh when new) batteries. We need to remove energy from it, cannot pump it back. I am just burning a few cents.


;-(
Anyways, in the old days as over-voltage protection : voltage sensor driving a thyristor to short the output
and primary fuse.
We don\'t want to short the power source and explode.
That was the classic protection against the series switching transistor failing.

The 200W Tarlington and 300W Qarlington are over-speced to avoid failure. In reality, i don\'t expect over 100W.
The power spec on the part assumes an infinite heat sink - on real heat sinks they get hot enough to fail at lower power dissipations.
I figure around 1/2 for the transistor and 1/2 for the resistor. TO-3 is rated for around 100W at 200C (0.6 W/C) with reasonable heat sink.

2N6287: 0.9W/C 160W 200C max.
A heat sink with 2x to 3x surface area should bring it down to 100C to 120C..
https://www.onsemi.com/pdf/datasheet/2n6284-d.pdf