I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the
capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the
capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the
capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert--
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote:
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the
capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >>> solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote:
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the >>capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >>solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote:
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the >>>capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >>>solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
On 2025-06-05 14:15, albert@spenarnc.xs4all.nl wrote:
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote:
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the
capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed
and a capacitor, to prey on the output. The circuit is not phased at all, >>>> solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
No, it won't work since A never becomes negative. And a cap in series
with a diode never works.
Try to find a copy of "The art of electronics" and do some studying.
This might work as long as the normal outputs are loaded (or else the
drive to A disappears).
It obtains a negative voltage from any waveform with enough amplitude.
A ---||-------|<------------- out
| _|_
_V_ ___
| |
GND --------------------------
Arie
In article <nnd$5972e5da$6d05f277@13e635c803c3f1a9>,
<albert@spenarnc.xs4all.nl> wrote:
In article <nnd$1620c1ab$7a0594d5@1745475ac2689b3d>,
Arie de Muijnck <noreply@ademu.nl> wrote:
On 2025-06-05 14:15, albert@spenarnc.xs4all.nl wrote:
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote: >>>>>
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the >>>>>> capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed >>>>>> and a capacitor, to prey on the output. The circuit is not phased at all,
solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
No, it won't work since A never becomes negative. And a cap in series >>>with a diode never works.
Try to find a copy of "The art of electronics" and do some studying.
This might work as long as the normal outputs are loaded (or else the >>>drive to A disappears).
It obtains a negative voltage from any waveform with enough amplitude.
A ---||-------|<------------- out
| _|_
_V_ ___
| |
GND --------------------------
Thanks. I'll try it.
I tried this and it generates a -4,3 voltage and less than 100 mV
ripple. Combined with the original 5 V output.
The 9.3 volt is ideal to simulate a 9V battery and indeed it
worked to power a voltmeter.
Then it started to draw more and more current. Have I made
a short circuit? I experiment on.
In article <nnd$1620c1ab$7a0594d5@1745475ac2689b3d>,
Arie de Muijnck <noreply@ademu.nl> wrote:
On 2025-06-05 14:15, albert@spenarnc.xs4all.nl wrote:
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote:
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the
circuit. The 2018 cuts the coil short to earth. The diode fill the
capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed >>>>> and a capacitor, to prey on the output. The circuit is not phased at all, >>>>> solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
No, it won't work since A never becomes negative. And a cap in series
with a diode never works.
Try to find a copy of "The art of electronics" and do some studying.
This might work as long as the normal outputs are loaded (or else the
drive to A disappears).
It obtains a negative voltage from any waveform with enough amplitude.
A ---||-------|<------------- out
| _|_
_V_ ___
| |
GND --------------------------
Thanks. I'll try it.
--Arie
Groetjes Albert
--
Temu exploits Christians: (Disclaimer, only 10 apostles)
Last Supper Acrylic Suncatcher - 15Cm Round Stained Glass- Style Wall
Art For Home, Office And Garden Decor - Perfect For Windows, Bars,
And Gifts For Friends Family And Colleagues.
On Tue, 17 Jun 2025 17:24:32 +0200, albert@spenarnc.xs4all.nl wrote:
In article <nnd$5972e5da$6d05f277@13e635c803c3f1a9>,
<albert@spenarnc.xs4all.nl> wrote:
In article <nnd$1620c1ab$7a0594d5@1745475ac2689b3d>,
Arie de Muijnck <noreply@ademu.nl> wrote:
On 2025-06-05 14:15, albert@spenarnc.xs4all.nl wrote:
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote: >>>>>>
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the >>>>>>> circuit. The 2018 cuts the coil short to earth. The diode fill the >>>>>>> capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed >>>>>>> and a capacitor, to prey on the output. The circuit is not phased at all,
solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
No, it won't work since A never becomes negative. And a cap in series >>>>with a diode never works.
Try to find a copy of "The art of electronics" and do some studying.
This might work as long as the normal outputs are loaded (or else the >>>>drive to A disappears).
It obtains a negative voltage from any waveform with enough amplitude.
A ---||-------|<------------- out
| _|_
_V_ ___
| |
GND --------------------------
Thanks. I'll try it.
I tried this and it generates a -4,3 voltage and less than 100 mV
ripple. Combined with the original 5 V output.
The 9.3 volt is ideal to simulate a 9V battery and indeed it
worked to power a voltmeter.
Then it started to draw more and more current. Have I made
a short circuit? I experiment on.
It gets interesting when the load is from V+ to V-.
It might help to put a bit of dummy load on the V+ side.
In article <o0435k51sa6bk58ppkt58d1o2qsmtq7n0t@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Tue, 17 Jun 2025 17:24:32 +0200, albert@spenarnc.xs4all.nl wrote:phased at all,
In article <nnd$5972e5da$6d05f277@13e635c803c3f1a9>,
<albert@spenarnc.xs4all.nl> wrote:
In article <nnd$1620c1ab$7a0594d5@1745475ac2689b3d>,
Arie de Muijnck <noreply@ademu.nl> wrote:
On 2025-06-05 14:15, albert@spenarnc.xs4all.nl wrote:
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote: >>>>>>>
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the >>>>>>>> circuit. The 2018 cuts the coil short to earth. The diode fill the >>>>>>>> capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed >>>>>>>> and a capacitor, to prey on the output. The circuit is not
solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the >>>>>> diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
No, it won't work since A never becomes negative. And a cap in series >>>>>with a diode never works.
Try to find a copy of "The art of electronics" and do some studying.
This might work as long as the normal outputs are loaded (or else the >>>>>drive to A disappears).
It obtains a negative voltage from any waveform with enough amplitude. >>>>>
A ---||-------|<------------- out
| _|_
_V_ ___
| |
GND --------------------------
Thanks. I'll try it.
I tried this and it generates a -4,3 voltage and less than 100 mV
ripple. Combined with the original 5 V output.
The 9.3 volt is ideal to simulate a 9V battery and indeed it
worked to power a voltmeter.
Then it started to draw more and more current. Have I made
a short circuit? I experiment on.
It gets interesting when the load is from V+ to V-.
It might help to put a bit of dummy load on the V+ side.
I rebuilt the circuit with other components, 10 uF electrolytic
capacitor and 1N4001 diode.
The symptoms are the same and diminish after a dummy load was applied.
of 10 mA. Then the negative voltage is ca -4V.
1 mA is not sufficient.
Can you give a rule of thumb? If the current from -5 to +5 is X mA,
how much should the dummy load be?
(I do not understand much of the circuit, apparently.)
Groetjes Albert--
On Thu, 05 Jun 2025 14:15:47 +0200, albert@spenarnc.xs4all.nl wrote:
In article <p50p3khhstse6vfn0u4hepdagvv83c5enq@4ax.com>,
john larkin <jl@glen--canyon.com> wrote:
On Sun, 01 Jun 2025 17:25:16 +0200, albert@spenarnc.xs4all.nl wrote:
I am experimenting with the 2018 step up converter.
The circuit is available from aliexpress , most everywhere.
There is a inductance, a Skottky diode, and capacitance, and the >>>>circuit. The 2018 cuts the coil short to earth. The diode fill the >>>>capacitor and the output is measured for a feedback.
Textbook step up. Rock solid 5 Volt.
Now I have this (apparently) wild idea. I add another diode reversed >>>>and a capacitor, to prey on the output. The circuit is not phased at all, >>>>solid 5.08 V as far is it original function.
But I get a couple of negative millivolt out.
What am I doing wrong? Or should this work?
I checked this over and over again.
Groetjes Albert
That's a lot of words. Can you post schematics?
The IC is not drawn. (it connects A B and ground)
Vi Vo
--------UUUUUU-------I>|----------+
A B |
|
|
=
|
|
---------------------------------+
|
_
-
.
Vi and Vo are 1.5 V and 5 V.
The switch is connected to A (connect to ground)
and the voltage is sensed at B.
Now I want to add a negative voltage.
Now I want a negative voltage.
On second thought I came up with this addition:
A
--------II-----------|<I------+----+
| |
| |
- |
A =
| |
| |
-----------------------------+----+
|
_
-
.
Can this work?
P.S.
I have 10 of those tiny boards.
The funny thing is I can remove the ic from one board, reverse the
diode and replace the coil with a capacitor.
What remain is add the extra diode over the capacitor and
connect grounds.
Groetjes Albert
Yikes. Ascii art.
Given the ususal non-synchronous buck switcher, series switch with a
catch diode, you can get a modest negative voltage as I think you
suggest, namely a series cap and a DC-restore circuit, sometimes
called a "half wave voltage doubler."
Or you can add a winding to the inductor and rectify that.
One picture is worth a thousand words.
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