E
Ed Lee
Guest
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.
Navigation
Install the app
How to install the app on iOS
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
More options
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
M
Martin Brown
Guest
On 25/08/2022 14:49, Ed Lee wrote:
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.
--
Regards,
Martin Brown
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.
--
Regards,
Martin Brown
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 7:36:03 AM UTC-7, Martin Brown wrote:
Nothing wrong, just trying to avoid plan B. A is TL432, C is MJ11011. Need B in between.
MJ11011 needs 5V base voltage and 1A base current. Unless there is a triple Darlington available.
I figure 500mA should drive around .5A base and 10A collector.
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.
Nothing wrong, just trying to avoid plan B. A is TL432, C is MJ11011. Need B in between.
MJ11011 needs 5V base voltage and 1A base current. Unless there is a triple Darlington available.
I figure 500mA should drive around .5A base and 10A collector.
D
Don
Guest
Martin Brown wrote:
Good question. The TL43x High-Current circuit\'s shown in Figure 29 on my
own datasheet, last revised in November 2018:
<https://crcomp.net/misc/tl43x.png>
It seems we talked about the circuit\'s 2N222 misnomer in years past.
A couple of open questions:
1. What\'s the name for two transistors topologically connected as such?
2. What\'s the circuit\'s maximum \"high current?\"
Danke,
--
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.
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.
Good question. The TL43x High-Current circuit\'s shown in Figure 29 on my
own datasheet, last revised in November 2018:
<https://crcomp.net/misc/tl43x.png>
It seems we talked about the circuit\'s 2N222 misnomer in years past.
A couple of open questions:
1. What\'s the name for two transistors topologically connected as such?
2. What\'s the circuit\'s maximum \"high current?\"
Danke,
--
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 8:13:43 AM UTC-7, Ed Lee wrote:
BTW, page 3 of this data sheet is wrong: 11/13/15 should be PNP and 12/14/16 should be NPN.
https://www.farnell.com/datasheets/685198.pdf
I ordered PNP (TIP127) last month and they shipped me NPN (TIP122). Didn\'t check before. Too late to protest on ebay. Waiting for another order to come.
On Thursday, August 25, 2022 at 7:36:03 AM UTC-7, Martin Brown 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.
Nothing wrong, just trying to avoid plan B. A is TL432, C is MJ11011. Need B in between.
MJ11011 needs 5V base voltage and 1A base current. Unless there is a triple Darlington available.
I figure 500mA should drive around .5A base and 10A collector.
BTW, page 3 of this data sheet is wrong: 11/13/15 should be PNP and 12/14/16 should be NPN.
https://www.farnell.com/datasheets/685198.pdf
I ordered PNP (TIP127) last month and they shipped me NPN (TIP122). Didn\'t check before. Too late to protest on ebay. Waiting for another order to come.
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 8:24:13 AM UTC-7, Don wrote:
Double Darlington. I need Triple Darlington for 10A to 20A.
> 2. What\'s the circuit\'s maximum \"high current?\"
Assuming that\'s a typo and they missed a \'2\'. 2N2222 is 0.6A.
Martin Brown wrote:
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.
Good question. The TL43x High-Current circuit\'s shown in Figure 29 on my
own datasheet, last revised in November 2018:
https://crcomp.net/misc/tl43x.png
It seems we talked about the circuit\'s 2N222 misnomer in years past.
A couple of open questions:
1. What\'s the name for two transistors topologically connected as such?
Double Darlington. I need Triple Darlington for 10A to 20A.
> 2. What\'s the circuit\'s maximum \"high current?\"
Assuming that\'s a typo and they missed a \'2\'. 2N2222 is 0.6A.
S
server
Guest
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
Boost it with a transistor.
<edward.ming.lee@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
Boost it with a transistor.
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
But why? If they are closely matched, would be any worst than parallel MOSFET.
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
S
server
Guest
On Thu, 25 Aug 2022 08:55:57 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
Paralleled mosfets don\'t share current well in linear mode. As
switches, their similar Rds-on gives pretty good current sharing.
<edward.ming.lee@gmail.com> wrote:
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
Paralleled mosfets don\'t share current well in linear mode. As
switches, their similar Rds-on gives pretty good current sharing.
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 9:03:15 AM UTC-7, jla...@highlandsniptechnology.com wrote:
How about a small (couple ohms) current limiting resistor?
I am trying to make a small PCB under the TO-3 case. A (SOT23) and C (TO-3). B between them would need to be a big TO-220.
Ideal case is a Tarlington (Triple Darlington) with smaller base current.
More ideal case is a 20A TL432 in TO-3.
On Thu, 25 Aug 2022 08:55:57 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
How about a small (couple ohms) current limiting resistor?
I am trying to make a small PCB under the TO-3 case. A (SOT23) and C (TO-3). B between them would need to be a big TO-220.
Ideal case is a Tarlington (Triple Darlington) with smaller base current.
More ideal case is a 20A TL432 in TO-3.
S
server
Guest
On Thu, 25 Aug 2022 09:14:54 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
The dynamic impedance and voltage tolerance determine current sharing.
It looks bad for hard-paralleled parts. A couple of ohms per chip
would help a lot, as would using the 0.5% parts. I assume the 1% parts
are bin-outs.
But exactly what do you want to do? Build an X? volts 500 mA shunt
regulator?
It looks easy to boost the TL with a transistor, or better a mosfet if
there\'s enough voltage available for the gate drive.
A schematic of your situation would help. Too many possibilities.
<edward.ming.lee@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:03:15 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 08:55:57 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
How about a small (couple ohms) current limiting resistor?
The dynamic impedance and voltage tolerance determine current sharing.
It looks bad for hard-paralleled parts. A couple of ohms per chip
would help a lot, as would using the 0.5% parts. I assume the 1% parts
are bin-outs.
But exactly what do you want to do? Build an X? volts 500 mA shunt
regulator?
I am trying to make a small PCB under the TO-3 case. A (SOT23) and C (TO-3). B between them would need to be a big TO-220.
Ideal case is a Tarlington (Triple Darlington) with smaller base current.
More ideal case is a 20A TL432 in TO-3.
It looks easy to boost the TL with a transistor, or better a mosfet if
there\'s enough voltage available for the gate drive.
A schematic of your situation would help. Too many possibilities.
M
Martin Brown
Guest
On 25/08/2022 16:13, Ed Lee wrote:
That is way too cryptic to make any sense of. What are you trying to do?
> MJ11011 needs 5V base voltage and 1A base current. Unless there is a triple Darlington available.
You are confused. Darlingtons drop more voltage across the device but
at 10A collector current I\'d expect Vbe(sat) ~ 2v and Vce(sat) ~ 2.5v.
That is a darlington pair with a min gain somewhere between 200 (@ 30A)
and 1000 (@ 20A). It should be fine at 10A with a 100mA base current.
The device gain should be around 3000 at 10A (it would be even more
nearer 8000x if you used an NPN version). See DC current gain vs Ic.
--
Regards,
Martin Brown
On Thursday, August 25, 2022 at 7:36:03 AM UTC-7, Martin Brown 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.
Nothing wrong, just trying to avoid plan B. A is TL432, C is MJ11011. Need B in between.
That is way too cryptic to make any sense of. What are you trying to do?
> MJ11011 needs 5V base voltage and 1A base current. Unless there is a triple Darlington available.
You are confused. Darlingtons drop more voltage across the device but
at 10A collector current I\'d expect Vbe(sat) ~ 2v and Vce(sat) ~ 2.5v.
I figure 500mA should drive around .5A base and 10A collector.
That is a darlington pair with a min gain somewhere between 200 (@ 30A)
and 1000 (@ 20A). It should be fine at 10A with a 100mA base current.
The device gain should be around 3000 at 10A (it would be even more
nearer 8000x if you used an NPN version). See DC current gain vs Ic.
--
Regards,
Martin Brown
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 9:27:18 AM UTC-7, jla...@highlandsniptechnology.com wrote:
We can sort them out with matching reference resistors.
Drive 5V 1A of the MJ11011
Just the classic Triple Transistors circuit, usually with TO-92, TO-220 and TO-3, but i want to use SOT-23 and TO-3 only.
On Thu, 25 Aug 2022 09:14:54 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:03:15 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 08:55:57 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
How about a small (couple ohms) current limiting resistor?
The dynamic impedance and voltage tolerance determine current sharing.
It looks bad for hard-paralleled parts. A couple of ohms per chip
would help a lot, as would using the 0.5% parts. I assume the 1% parts
are bin-outs.
We can sort them out with matching reference resistors.
But exactly what do you want to do? Build an X? volts 500 mA shunt
regulator?
Drive 5V 1A of the MJ11011
I am trying to make a small PCB under the TO-3 case. A (SOT23) and C (TO-3). B between them would need to be a big TO-220.
Ideal case is a Tarlington (Triple Darlington) with smaller base current.
More ideal case is a 20A TL432 in TO-3.
It looks easy to boost the TL with a transistor, or better a mosfet if
there\'s enough voltage available for the gate drive.
A schematic of your situation would help. Too many possibilities.
Just the classic Triple Transistors circuit, usually with TO-92, TO-220 and TO-3, but i want to use SOT-23 and TO-3 only.
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 9:32:20 AM UTC-7, Martin Brown wrote:
I explain a bit more in other posts.
That\'s the small signal DC current gain. We still need a substantial base current. The spec says 1A base current, no data on min or typical.
On 25/08/2022 16:13, Ed Lee wrote:
On Thursday, August 25, 2022 at 7:36:03 AM UTC-7, Martin Brown 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.
Nothing wrong, just trying to avoid plan B. A is TL432, C is MJ11011. Need B in between.
That is way too cryptic to make any sense of. What are you trying to do?
I explain a bit more in other posts.
MJ11011 needs 5V base voltage and 1A base current. Unless there is a triple Darlington available.
You are confused. Darlingtons drop more voltage across the device but
at 10A collector current I\'d expect Vbe(sat) ~ 2v and Vce(sat) ~ 2.5v.
I figure 500mA should drive around .5A base and 10A collector.
That is a darlington pair with a min gain somewhere between 200 (@ 30A)
and 1000 (@ 20A). It should be fine at 10A with a 100mA base current.
The device gain should be around 3000 at 10A (it would be even more
nearer 8000x if you used an NPN version). See DC current gain vs Ic.
That\'s the small signal DC current gain. We still need a substantial base current. The spec says 1A base current, no data on min or typical.
P
Phil Hobbs
Guest
Martin Brown wrote:
The 432 looks topologically like an NPN transistor with very high beta
(*). To get a higher-current shunt regulator, the OP can just turn it
into a Darlington:
Cathode to collector, anode to base,
resistor from base to emitter to take the min anode current from the 432
feedback pin used as normal.
Watch out for the transistor dissipation!
Cheers
Phil Hobbs
(*) The LM4041 and LM385 look like PNPs instead--you connect the
feedback to the anode to get 1.2V. That\'s sometimes very useful.
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
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.
The 432 looks topologically like an NPN transistor with very high beta
(*). To get a higher-current shunt regulator, the OP can just turn it
into a Darlington:
Cathode to collector, anode to base,
resistor from base to emitter to take the min anode current from the 432
feedback pin used as normal.
Watch out for the transistor dissipation!
Cheers
Phil Hobbs
(*) The LM4041 and LM385 look like PNPs instead--you connect the
feedback to the anode to get 1.2V. That\'s sometimes very useful.
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
S
server
Guest
On Thu, 25 Aug 2022 09:33:23 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
If you add voltage dividers er reg, their tolerances maks things
worse. Sharing a common divider is bad too.
Well, I said \"exactly.\" Can\'t help without understanding the issue.
<edward.ming.lee@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:27:18 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 09:14:54 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:03:15 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 08:55:57 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
How about a small (couple ohms) current limiting resistor?
The dynamic impedance and voltage tolerance determine current sharing.
It looks bad for hard-paralleled parts. A couple of ohms per chip
would help a lot, as would using the 0.5% parts. I assume the 1% parts
are bin-outs.
We can sort them out with matching reference resistors.
If you add voltage dividers er reg, their tolerances maks things
worse. Sharing a common divider is bad too.
But exactly what do you want to do? Build an X? volts 500 mA shunt
regulator?
Drive 5V 1A of the MJ11011
Well, I said \"exactly.\" Can\'t help without understanding the issue.
E
Ed Lee
Guest
On Thursday, August 25, 2022 at 9:45:35 AM UTC-7, Phil Hobbs wrote:
Almost all with 100mA limit.
I guess the question is what\'s needed to drive the MJ11011 types.
And do it twice for Tarlington.
> Watch out for the transistor dissipation!
Probably need a TO-220 for 0.5A to 1A between the SOT23 and TO-3.
Martin Brown 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.
The 432 looks topologically like an NPN transistor with very high beta
Almost all with 100mA limit.
(*). To get a higher-current shunt regulator, the OP can just turn it
into a Darlington:
I guess the question is what\'s needed to drive the MJ11011 types.
Cathode to collector, anode to base,
resistor from base to emitter to take the min anode current from the 432
feedback pin used as normal.
And do it twice for Tarlington.
> Watch out for the transistor dissipation!
Probably need a TO-220 for 0.5A to 1A between the SOT23 and TO-3.
S
server
Guest
On Thu, 25 Aug 2022 09:46:46 -0700, jlarkin@highlandsniptechnology.com
wrote:
(Sorry for the worse than usual spelling. I just had cataract surgery
and can\'t see well through this silly perforated shield. And I think
they got my focal length wrong.)
wrote:
On Thu, 25 Aug 2022 09:33:23 -0700 (PDT), Ed Lee
edward.ming.lee@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:27:18 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 09:14:54 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:03:15 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 08:55:57 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, August 25, 2022 at 8:53:47 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Thu, 25 Aug 2022 06:49:28 -0700 (PDT), Ed Lee
edward....@gmail.com> 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.
Paralleling shunt regulators is a generically bad idea.
But why? If they are closely matched, would be any worst than parallel MOSFET.
If you are intending to make a high-current shunt regulator, and you
put 5 small shunt regs in parallel, the one with marginally lower
voltage will hog all the current and fry. Paralleling zeners has the
same problem.
How about a small (couple ohms) current limiting resistor?
The dynamic impedance and voltage tolerance determine current sharing.
It looks bad for hard-paralleled parts. A couple of ohms per chip
would help a lot, as would using the 0.5% parts. I assume the 1% parts
are bin-outs.
We can sort them out with matching reference resistors.
If you add voltage dividers er reg, their tolerances maks things
worse. Sharing a common divider is bad too.
But exactly what do you want to do? Build an X? volts 500 mA shunt
regulator?
Drive 5V 1A of the MJ11011
Well, I said \"exactly.\" Can\'t help without understanding the issue.
(Sorry for the worse than usual spelling. I just had cataract surgery
and can\'t see well through this silly perforated shield. And I think
they got my focal length wrong.)
S
server
Guest
On Thu, 25 Aug 2022 09:54:47 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
Data sheet, fig 29.
<edward.ming.lee@gmail.com> wrote:
On Thursday, August 25, 2022 at 9:45:35 AM UTC-7, Phil Hobbs wrote:
Martin Brown 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.
The 432 looks topologically like an NPN transistor with very high beta
Almost all with 100mA limit.
(*). To get a higher-current shunt regulator, the OP can just turn it
into a Darlington:
I guess the question is what\'s needed to drive the MJ11011 types.
Cathode to collector, anode to base,
resistor from base to emitter to take the min anode current from the 432
feedback pin used as normal.
And do it twice for Tarlington.
Watch out for the transistor dissipation!
Probably need a TO-220 for 0.5A to 1A between the SOT23 and TO-3.
Data sheet, fig 29.
E
Ed Lee
Guest
> Watch out for the transistor dissipation!
Yes, assuming the SOT-23 can handle 1/4W. Over 12V range, it might only be able to sink 20mA (0.25/12). I might need to parallel a few buffering 2907s (0.5A over 5V, which is the MJ1101X base voltage range)
Yes, assuming the SOT-23 can handle 1/4W. Over 12V range, it might only be able to sink 20mA (0.25/12). I might need to parallel a few buffering 2907s (0.5A over 5V, which is the MJ1101X base voltage range)