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Flying Capacitor +5DC to -12VDC/-12VDC

G

Guy Macon

Jan 1, 1970
0
Take a look at the following +5DC to -12VDC/-12VDC
voltage multiplier/inverter:


------------o---------O +12VDC OUT
| |
+5VDC IN | | C
O --- -----
| / \ CR
| --- -----
|\| | |
| \ | | C | |
---| O-------| |-------o ---
| / | | | \ / GND
|/|74HC04 | V
| ---
| / \ CR
--- ---
\ / GND |
V |
o------------ (+8VDC)
| |
| | C
--- -----
/ \ CR
--- -----
|\ | |
| \ U | | C | |
---| O-------| |-------o ---
| / | | | \ / GND
|/ 74HC04 | V
---
/ \ CR
---
|
|
o------------ (+4VDC)
| |
| | C
--- -----
/ \ CR
--- -----
|\ | |
| \ U | | C | |
---| O-------| |-------o ---
| / | | | \ / GND
|/ 74HC04 | V
---
/ \ CR
---
|
|
o------------ (0VDC)
| |
| |
--- ---
/ \ CR \ / GND
--- V
|\ |
| \ U | | C |
---| O-------| |-------o
| / | | |
|/ 74HC04 |
---
/ \ CR
---
|
|
o-----------| (-4VDC)
| |
| | C
--- -----
/ \ CR
--- -----
|\ | |
| \ U | | C | |
---| O-------| |-------o ---
| / | | | \ / GND
|/ 74HC04 | V
---
/ \ CR
---
|
|
o-----------| (-8VDC)
| |
| | C
--- -----
/ \ CR
--- -----
|\ | |
| \ U | | C | |
---| O-------| |-------o ---
| / | | | \ / GND
|/ 74HC04 | V
---
/ \ CR
---
|
|
------------o---------O -12VDC OUT
|
| C
-----

-----
|
|
---
\ / GND
V


(Yes, I know about the noise and poor regulation...)

I haven't worked with these before, and a few questions
come to mind:



DRIVING FREQUENCY:
Is this just a simple matter of making it as fast as
possible while still keeping the gate and diode switching
times at a fraction of a percent? Or are there other
considerations I should be thinking of?



CAPACITOR SIZING

Should the top and bottom C be much larger than the rest?
(They *will* be if I use it to drive a board with bulk
bypass caps on it...) Should the caps on the right be
bigger than the flying caps on the left? How should I
decide how big the flying caps should be?




DRIVING PATTERN:

Assume that the HC inverter is driven by six uP pins, and
that the uP can put out any pattern at any reasonable
frequency. What's the best pattern to drive it with?
Should I switch one gate at a time, rippling upward
through the six gates (in other words, have each driver
be phased 60 degrees (360/6) later than the one
below it)? Or is there a better driving pattern?
 
J

Jan Panteltje

Jan 1, 1970
0
(Yes, I know about the noise and poor regulation...)

I haven't worked with these before, and a few questions
come to mind:
I do not know the answer these questions, but it has also an
incredible component count don't you think?

I used this many times, even in industrial:

-------------------------------- + 5V
| |
--- 10u |
=== /
| b |<e
| ---| BC557
| | |\ c (general purpose PNP)
| | \ 1N4148
| | --------------|>|---------------- + 12V
| | | | 1N4148 |
|-- --- | {20t |-----|<|------ - 12V |
| | 1t} | { | | |
2k2 [ ] | | | { === --- ===
| ----- | | | 22n === 10u --- 10u
| pot core| | pol | |
---------------------------------------------------------- GND

9 components, can deliver quite a bit of current.
Mind the phase of the feedback turn.
Decouple supply, but this does a sine wave like, so not much interference.
Oscillation a few kHz.
View with fixed font.
C1 is not wrong way around, it charges positive relative to the + 5V.
JP
 
J

Jan Panteltje

Jan 1, 1970
0
On a sunny day (Sun, 22 Feb 2004 12:01:58 -0800) it happened Guy Macon
<http://www.guymacon.com> wrote in <[email protected]>:

Oops, drawing error, ,the cllector needs to be on tap of coil
(or separate secondairy if you want isolation).
Number off the extra turns sets voltage for both + and -

-------------------------------- + 5V
| |
--- 10u |
=== /
| b |<e
| ---| BC557
| | |\ c (general purpose PNP)
| | \ 1N4148
| | | -----------|>|---------------- + 12V
| | | | | 1N4148 |
|-- --- || {30t |-----|<|------ - 12V |
| | 1t} | -{ | | |
2k2 [ ] | | | {20t === --- ===
| ----- | | | 22n === 10u --- 10u
| pot core| | pol | |
---------------------------------------------------------- GND

9 components, can deliver quite a bit of current.
Mind the phase of the feedback turn.
Decouple supply, but this does a sine wave like, so not much interference.
Oscillation a few kHz.
View with fixed font.
C1 is not wrong way around, it charges positive relative to the + 5V.
JP
 
G

Guy Macon

Jan 1, 1970
0
Jan Panteltje said:
-------------------------------- + 5V
| |
--- 10u |
=== /
| b |<e
| ---| BC557
| | |\ c (general purpose PNP)
| | \ 1N4148
| | | -----------|>|---------------- + 12V
| | | | | 1N4148 |
|-- --- || {30t |-----|<|------ - 12V |
| | 1t} | -{ | | |
2k2 [ ] | | | {20t === --- ===
| ----- | | | 22n === 10u --- 10u
| pot core| | pol | |
---------------------------------------------------------- GND

9 components, can deliver quite a bit of current.

Nice design! Mine uses 25 components, but the total cost is
lower and mine has positive and negative outputs. Of course
yours becomes a dual output with a transformer change and a
few extra components. I am going to file it away for future
reference. Thanks!
 
J

Jan Panteltje

Jan 1, 1970
0
Jan Panteltje said:
-------------------------------- + 5V
| |
--- 10u |
=== /
| b |<e
| ---| BC557
| | |\ c (general purpose PNP)
| | \ 1N4148
| | | -----------|>|---------------- + 12V
| | | | | 1N4148 |
|-- --- || {30t |-----|<|------ - 12V |
| | 1t} | -{ | | |
2k2 [ ] | | | {20t === --- ===
| ----- | | | 22n === 10u --- 10u
| pot core| | pol | |
---------------------------------------------------------- GND

9 components, can deliver quite a bit of current.

Nice design! Mine uses 25 components, but the total cost is
lower and mine has positive and negative outputs. Of course
yours becomes a dual output with a transformer change and a
few extra components. I am going to file it away for future
reference. Thanks!
hey, mine gives + and - 12 V, what do you mean?
Anyways I am glad it is of use to someone.
JP
 
G

Guy Macon

Jan 1, 1970
0
Jan Panteltje said:
hey, mine gives + and - 12 V, what do you mean?

Ooops. Looks lke my brain got a couple of the lower
order address lines switched... Sorry about that.
 
G

GPG

Jan 1, 1970
0
Guy Macon said:
Take a look at the following +5DC to -12VDC/-12VDC
voltage multiplier/inverter:
Try this:



A B
+5V ->|---------o--->|---o---->|----o------- +V
| | |
In1 --- --- ---
.- --- --- ---
| |\ INV1 | | |
|------| >O----------o | GND
| |/ |
| |
| |
| |\ INV2 |
| .---| >O--o----------------o
| | |/
| |
| | o----------------------------o
| | | |
| | | ---
| | | ---
| | |\ | || C |
| |---| >O'-||---o--|<-----o------|<---o-----|<----o -V
| | |/ || | | D |
| | V | ---
| | - | ---
| | --- |
| In2 === --- |
| GND | ===
| | GND
| |\ |
o------| >O-----------------o
|/
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
Drive in 1 & 2 in antiphase
 
G

GPG

Jan 1, 1970
0
POST AGAIN



A B
+5V ->|---------o--->|---o---->|----o------- +V
| | |
In1 --- --- ---
.- --- --- ---
| |\ INV1 | | |
|------| >O----------o | GND
| |/ |
| |
| |
| |\ INV2 |
| .---| >O--o----------------o
| | |/
| |
| | o----------------------------o
| | | |
| | | ---
| | | ---
| | |\ | || C |
| |---| >O'-||---o--|<-----o------|<---o-----|<----o -V
| | |/ || | | D |
| | V | ---
| | - | ---
| | --- |
| In2 === --- |
| GND | ===
| | GND
| |\ |
o------| >O-----------------o
|/
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
 
G

GPG

Jan 1, 1970
0
POST AGAIN



A B
+5V ->|---------o--->|---o---->|----o------- +V
| | |
In1 --- --- ---
.- --- --- ---
| |\ INV1 | | |
|------| >O----------o | GND
| |/ |
| |
| |
| |\ INV2 |
| .---| >O--o----------------o
| | |/
| |
| | o----------------------------o
| | | |
| | | ---
| | | ---
| | |\ | || C |
I I---| >O'-||---o--|<-----o------|<---o-----|<----o -V
| | |/ || | | D |
| | V | ---
| | - | ---
| | --- |
| In2 === --- |
| GND | ===
| | GND
| |\ |
o------| >O-----------------o
|/
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
Fix?
 
G

GPG

Jan 1, 1970
0
Another go simplified


|\ |\
-| >O|-------------| >O-
|/ A |/ B




+5V ->|-----o------>|-----o----->|-------o----- +V
| | |
--- --- ---
--- --- ---
| | |
A B GND

A B A GND
| | | |
--- --- --- ---
--- --- --- ---
| | | |
|-----|<------o------|<------o-----|<----o----- -V
|
|
|
V
-
|
GND
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
Inverters could be paralleled sections to improve current drive
 
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