generating 180VDC at 5mA or so, simply...

[Mike Deblis]

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it should
be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike

 

[James Beck]

In article <ch2n7j$kvi$1@hercules.btinternet.com>, mdeblis@hotmail.com
says...

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it should
be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike

I would say that 1% regulation pretty critical.
I was going to suggest a 555 type ocillator with maybe a drive
transistor and a step up transformer, but if a +- 1% is needed
then........

Jim

 

[Joerg]

Hi Mike,

A little ferrite transformer, a chip, a FET and a few discrete parts
will get you there, including the 1% spec. I suggest to check out the
LM3478. A BSS 123 could do as the FET if you use a transformer.

Regards, Joerg

http://www.analogconsultants.com

 

[Ken Smith]

In article <ch2n7j$kvi$1@hercules.btinternet.com>,
Mike Deblis <mdeblis@hotmail.com> wrote:

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply

Why not MAX or LT? In terms of component count a chip will save you many
parts.

- a minimum of discrete components (maybe a small
hand-wound small inductor)

Are you excluding a purchased inductor? If you want low parts count an
inductor will really help.

- regulation is not critical but needs to be
about 1% or so.

What's the "or so"? If you want better than 2% your life will be harder.




--
--
kensmith@rahul.net forging knowledge

 

[Jeff]

You may want to take a look at the IC's designed to drive EL panels - these
should be just about the right current for a larger panel and the voltage is
in that range. Note that a EL panel requires AC, so you would need to
rectify and filter it to DC. Very small (SMT parts, usually designed to be
put into small hand held devices), cheap, very simple, usually requiring
only a few components, etc.

To achieve that 1% regulation requirement, it might be a little difficult,
and you may need do some interesting things, like post regulation on the HV
(2 W zener diode shunting excess voltage away, or an more elaborate setup
using a pass transistor), or regulate the low voltage while keeping the load
constant on the HV, feedback to control the PWM/EL panel driver, feedback to
control the voltage going to the EL driver such as a LM317 with feedback
from the HV which feeds the EL driver, etc.

Also, why the so tight regulation? You realize you want it to be within 1.8V
of 180V under all conditions? What are you intending to do with this 180V?


"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:ch2n7j$kvi$1@hercules.btinternet.com...

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it
should
be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike

 

[Ken Smith]

In article <Zk6Zc.10292$QJ3.3043@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:

Hi Mike,

A little ferrite transformer, a chip, a FET and a few discrete parts
will get you there, including the 1% spec. I suggest to check out the
LM3478. A BSS 123 could do as the FET if you use a transformer.

Pick the right chip and no FET is needed.

The power level is only about 1/2 Watt.

--
--
kensmith@rahul.net forging knowledge

 

[Genome]

"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:ch2n7j$kvi$1@hercules.btinternet.com...

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it
should
be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike

Voltage boosted boost converter in alt.binaries.schematics.electronics.

DNA

 

[john jardine]

"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:ch2n7j$kvi$1@hercules.btinternet.com...

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it
should
be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike


A 200V, 0.3 ohm, logic switched, N-fet such as 2SK2350. Drain to inductor to

supply voltage. pick off drain voltage via diode and store on a cap. Drive
fet with pwm chip etc. Make sure coil R is low.
regards
john

 

[Mike Deblis]

"Mike Deblis" <mdeblis@hotmail.com> wrote in message news:<ch2n7j$kvi$1@hercules.btinternet.com>...

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).
....

I should qualify this - 2% or 3% regulation is probably fine, and this
is an exercise (not a class - I'm far too old for that!) in NOT using
a switcher chip - I'm well aware of their advantages in commercial
products, but this is just a bit of fun to see how simple such a
non-critical PSU can be made. I've use LT and MAX (771/1771) for
exactly this sort of PSU, but I don't need their 80-90% efficiencies
and 1% reg etc. Its more a question of "given a couple of discrete
semiconductors and a few passives, plus a hand-wound small inductor,
can something good enough be made"? i.e. "outside the box" thinking...

The object is to drive some neon dischange tubes that strike at about
180VDC and which take about 2mA or so each.

Mike

 

[Jeff]

For driving a Neon tube, you don't need regulation that tight, or possibly
at all. Neon changes it's striking voltage with temp, and if it's iluminated
or not anyway. You also don't need DC.

As for a simple circuit, take one of those minature 8 ohm center tapped to
1000 ohm speaker transformers, connect the neon tube across the 1000 ohm
side, and connect power to the center tap on the 8 ohm side, drive the one
leg of the 8 ohm side with a transistor to the other power polarity
(dependant on transistor polarity), and use the other winding for feedback
to drive the base of the transistor through a cap and resistor.


"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:bc45f679.0409010100.6e9263c1@posting.google.com...

"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:<ch2n7j$kvi$1@hercules.btinternet.com>...
Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).
...

I should qualify this - 2% or 3% regulation is probably fine, and this
is an exercise (not a class - I'm far too old for that!) in NOT using
a switcher chip - I'm well aware of their advantages in commercial
products, but this is just a bit of fun to see how simple such a
non-critical PSU can be made. I've use LT and MAX (771/1771) for
exactly this sort of PSU, but I don't need their 80-90% efficiencies
and 1% reg etc. Its more a question of "given a couple of discrete
semiconductors and a few passives, plus a hand-wound small inductor,
can something good enough be made"? i.e. "outside the box" thinking...

The object is to drive some neon dischange tubes that strike at about
180VDC and which take about 2mA or so each.

Mike

 

[Steve]

Mike Deblis wrote:

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it
should be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike

Mike,
Check out the July 8th, 2004 EDN issue. It has a tranformerless
design idea. Have no idea if the unmodified design can maintain the
regulation you require, but...

http://www.reed-electronics.com/ednmag/toc/7/8/2004/

Look for the transformerless 12 to 180v supply midway down the page
or so.

Thanks, Steve

 

[John Fields]

On Wed, 1 Sep 2004 03:23:00 +0000 (UTC), kensmith@green.rahul.net (Ken
Smith) wrote:

In article <Zk6Zc.10292$QJ3.3043@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:
Hi Mike,

A little ferrite transformer, a chip, a FET and a few discrete parts
will get you there, including the 1% spec. I suggest to check out the
LM3478. A BSS 123 could do as the FET if you use a transformer.

Pick the right chip and no FET is needed.

The power level is only about 1/2 Watt.

---
180V * 0.005A = 0.9W

Tsk, tsk, tsk. ;^)

--
John Fields

 

[Genome]

"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:bc45f679.0409010100.6e9263c1@posting.google.com...

"Mike Deblis" <mdeblis@hotmail.com> wrote in message
news:<ch2n7j$kvi$1@hercules.btinternet.com>...
Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).
...

I should qualify this - 2% or 3% regulation is probably fine, and this
is an exercise (not a class - I'm far too old for that!) in NOT using
a switcher chip - I'm well aware of their advantages in commercial
products, but this is just a bit of fun to see how simple such a
non-critical PSU can be made. I've use LT and MAX (771/1771) for
exactly this sort of PSU, but I don't need their 80-90% efficiencies
and 1% reg etc. Its more a question of "given a couple of discrete
semiconductors and a few passives, plus a hand-wound small inductor,
can something good enough be made"? i.e. "outside the box" thinking...

The object is to drive some neon dischange tubes that strike at about
180VDC and which take about 2mA or so each.

Mike

Jeeez. Discrete version now in alt.binaries.schematics.electronic.

DNA

 

[Yzordderex]

I certainly like the idea of doing stuff just for fun.

Maybe a 555 would work for you to control a boost
converter. Drive the previous mentioned fet.

You say discreet components. Maybe a pair of transistors
operated in freerunning mode to run boost converter. Could
do bang-bang control and run the thing in burst mode. Maybe
you can do the whole thing with 3 bipolar transistors and a fet.
Maybe all bipolars.

regards,
Bob





mdeblis@hotmail.com (Mike Deblis) wrote in message news:<bc45f679.0409010100.6e9263c1@posting.google.com>...

"Mike Deblis" <mdeblis@hotmail.com> wrote in message news:<ch2n7j$kvi$1@hercules.btinternet.com>...
Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).
...

I should qualify this - 2% or 3% regulation is probably fine, and this
is an exercise (not a class - I'm far too old for that!) in NOT using
a switcher chip - I'm well aware of their advantages in commercial
products, but this is just a bit of fun to see how simple such a
non-critical PSU can be made. I've use LT and MAX (771/1771) for
exactly this sort of PSU, but I don't need their 80-90% efficiencies
and 1% reg etc. Its more a question of "given a couple of discrete
semiconductors and a few passives, plus a hand-wound small inductor,
can something good enough be made"? i.e. "outside the box" thinking...

The object is to drive some neon dischange tubes that strike at about
180VDC and which take about 2mA or so each.

Mike

 

[Ken Smith]

In article <jhibj0da5addam42bo74u7lff63d0aptas@4ax.com>,
John Fields <jfields@austininstruments.com> wrote:

On Wed, 1 Sep 2004 03:23:00 +0000 (UTC), kensmith@green.rahul.net (Ken
Smith) wrote:
[...]
The power level is only about 1/2 Watt.

180V * 0.005A = 0.9W

Tsk, tsk, tsk. ;^)

Drat!

The LT1930 would still be in the running though.


--
--
kensmith@rahul.net forging knowledge

 

[Ian]

On Wed, 1 Sep 2004 18:19:11 +0000 (UTC), Ken Smith <kensmith@green.rahul.net> wrote:

Why not use the neon tubes as part of the voltage regulation. ie: control
the current through them.

Similar to how I've done it: PIC PWM driving logic MOSFET, 1:10 transformer on
small E-core, bang-bang "regulation" through PIC analog comparator. Tubes driven
by switched current sink (1 x MPSA42 per digit, driven direct from PIC with only
one low-power resistor needed per tube). Protection by zener and thermal fuse on
the MOSFET. PIC also does the clock stuff. Takes a few liberties but has a low
parts count and works quite well...

http://projects.jusme.com/cgi-bin/projects/projects/index.pl?id:nixieclock1

(pdf's of the schematics on the "files" page)

--
Ian

'Milk below!'

 

[John Larkin]

On Tue, 31 Aug 2004 20:31:47 +0000 (UTC), "Mike Deblis"
<mdeblis@hotmail.com> wrote:

Hi,

I was wondering how to generate about 180VDC continuous at a few mA (at
least 5) from 9-12VDC in (no mains).

The MAX/LT etc. switchers are not in the frame for this - I want to do it
very very simply - a minimum of discrete components (maybe a small
hand-wound small inductor) - regulation is not critical but needs to be
about 1% or so. No back-to-front mains transformers (far too big - it should
be very small).

Ideas welcome - the simpler, the smaller, the neater, the better...

Many thanks for any pointers,

Mike

CMOS schmitt trigger oscillator,

driving small mosfet,

driving single inductor in flyback mode,

diode+cap or voltage doubler, depending on fet voltage and stuff

bit of series r into neons

feed back neon current into schmitt oscillator to
regulate drive after tubes strike.

12 parts maybe.

John

 

[Ken Smith]

In article <bc45f679.0409010100.6e9263c1@posting.google.com>,
Mike Deblis <mdeblis@hotmail.com> wrote:
[...]

The object is to drive some neon dischange tubes that strike at about
180VDC and which take about 2mA or so each.

Why not use the neon tubes as part of the voltage regulation. ie: control
the current through them.

--
--
kensmith@rahul.net forging knowledge

 

[Joerg]

Hi Ken,

The LT1930 would still be in the running though.


But it costs almost $2 versus about $1 for the LM3478. Sans FET, but a

lil' BSS123 is only 6 cents or so. Ok, I'd take two of them and that
would be 12 cents.

Just my 12 cents.

Regards, Joerg

http://www.analogconsultants.com

 

[Joerg]

Hi Ken,

You didn't included the cost of shipping and handling. That brings the
price of the BSS123 up to $25.06.


Alternatively you could visit the next ham radio operator and trade a

nice bottle of Sierra Nevada Pale Ale for a couple 2N7002. They always
have these but they are only good for 60V. Considering that a six-pack
runs about $6 you would at least break even on this design

Regards, Joerg

http://www.analogconsultants.com