Introduction: DC-DC HV Boost Converter

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Step 1: Operation and Electronics Intro

How Does A Boost Converter Work?
Basic Principal:
A boost converter works in two stages, ON and OFF. In the ON stage the Semi-conductive Switch is conducting and current builds up in the inductor producing an
electromagnetic field, this field stores energy. In the OFF stage the Semi-conductive Switch does not conduct and the electromagnetic field collapses. When the field collapses the energy stored
in it can not escape through the Semi-conductive Switch so it goes through the diode and into the load/Capacitor at a much higher voltage. This happens several
thousand times a second via the pulses from the NE555 Timer Chip and the result is being able to charge a high voltage capacitor from a low voltage source.
Below is some aid for those of you who do not know electronics well.

R-Resistor
VR-Variable Resistor (also called a Potentiometer)
B-Battery
V-Voltage Source
C-Capacitor
D-Diode
L-Inductor
U / IC-Integrated Circuit
Q-Transistor / IGBT
M-MOSFET
GND- Ground (Negative terminal of Battery for Portable Applications)

Some Diagrams and Charts are shown below to help you further.

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Step 2: Protoboard Boost Converter 500V

This boost converter is for those with moderate electronics experience.

If you have the resources I recommend making the printed circuit board version of this device because it is simpler, smaller, and less likely to fail. However feel free to make the protoboard version if space is not an issue.

This circuit takes up a minimum of 1.75" x 1.5" x 1" and can operate from 8.4V to 31.2V Input and output maximum of 500V safely (for the circuit). I recommend at least a 12V battery input.

DANGER HIGH VOLTAGE
This device can put out lethal voltages and the capacitors you charge can store lethal charges for hours, Please wear Electrician Gloves and Safety Glasses while operating and take all safety precautions


Specifications:

Project Cost:
- $17 + Shipping Mouser
- $5 + Shipping Coilcraft PCV-2-394-05L (Follow the link and type in the part number to buy)
- Average Total Cost with Shipping
-- $35 --

Dimensions: 1.75" x 1.5" x 1"
Input Voltage: 8.4V to 31.2V
Output Voltage Range: 100V to 500V
Output Power:

- 12V Input 36W maximum +-20% Charged 290J Capacitor Bank in 8s
- 24V Input 92W maximum +-20% Charged 1468J Capacitor Bank in 16s

Output Power Measured with 1-2 12V 34Ah Lead Acid Batteries for a Virtually Constant Voltage Source

The Major limitation of how much power can be drawn from your batteries is the Battery Packs ESR

---For Best results used high current rated batteries or Batteries meant for Power RC Devices---NiCd are the best (with the exception of Li-poly)
For The Following Batteries an Estimated Maximum Power can be drawn
ESR = Equivalent Series Resistance = Internal Resistance

NiCD/NiMH
12V AAA ESR = 350-400mOhm 28-30W
12V AA ESR = 150-300mOhm 31-34W
24V AAA ESR = 700-800mOhm 60-80W
24V AA ESR = 300-600mOhm 75-85W

Warning-Drawing too much current from your batteries may reduce there capacity, life, and cause your battery to over heat, Monitor Your Batteries temperature.

Note: The Protoboard holes do not accommodate the MOSFET and Diode pins, drilling a 1/32 hole solves this, although you may have to solder the leads to adjacent pads.

Step 3: Protoboard Boost Converter 500V Parts

Tools:


Materials:
- Protoboard (The Link is the protoboard I used, Protoboard Sets)

Parts Bought From Mouser:

U2- Voltage Regulator -
Battery Input Part Number

-8.4V to 12V LF60CV
-12V to 13.2V LD1086V90
-13.2V to 16.8V LM7809ACT
-16.8V to 26.4V LM7812ACT
-26.4V to 31.2V LM317 Any TO-220 (R1 = 500 Ohm R2 = 5.5 k Ohm) See Data sheet
--- Test That Output is 15V for LM317 ---

For C1, C2, C3, and CT use a voltage rating according to this:
Battery Voltage..........Capacitor Rated Voltage

<=12V Bat..............................>=16V Cap
<=20V Bat.........................>=25V Cap
<=30V Bat.........................>=50V Cap

-- C2 Type According to Regulator Used: --
LF60CV Electrolytic
LD1086V90 Electrolytic
LM7809ACT Ceramic
LM7812ACT Ceramic
LM317 Electrolytic

-- C1 and C3 are Ceramic Disc or MLCC Leaded 5%-20%, or -20% to +80% --
-- CT is Ceramic Disc or MLCC Leaded 1%-10% --
-- All Resistors except for Rdiv1 is 1/10W or greater --

-2 8-DIP Sockets
-C1- 0.33uF (330nF) or More
-C2- 10uF
-C3- 0.01uF (10nF)
-CB1- Any Capacitor Bank You Wish To Charge
-CT- 0.022uF (22nF)
-LEDPWR- Indicates Power is Applied
-LEDREG- Indicates Desired Voltage is Reached
-LEDGATE- Indicates NE555 is sourcing voltage to the MOSFET
-R1, R2, R3 - 1kOhm(<12V) or 2kOhm(>=12V) 1%-5%
-RA- 15kOhm (2% or better)
-RB- 10kOhm (2% or better)
-Rdiv1- 1MOhm (2% or better , 1/4W or greater)

-Rdiv2-
Regulator Used Value (2% or Better)
LF60CV 11kOhm
LD1086V90 16kOhm
LM7809ACT 16kOhm
LM7812ACT 22.3kOhm
LM317 28kOhm

-SW1- Rated for input voltage and 5-6A
-U1 and U1.1(Same Chip) - LM393AN
-U3- SE555P
-VR1- 10kOhm Potentiometer (Multi-turn will be more precise)

-M1- FCA47N60(F)
-D1- RURG3060 (Use the RURG30120 if this is your first electronic project)

Coilcraft:
L1- Coilcraft PCV-2-394-05L (Follow the link and type in the part number to buy)

PIN NUMBERS ARE ON THE SCHEMATIC
CLICK THE " i " AT THE TOP OF THE SCHEMATIC FOR A LARGER DOWNLOADABLE VIEW

Step 4: PCB Boost Converter 500V

If you have the resources I strongly suggest the you make this Printed circuit Board Boost converter instead of the protoboard one. Making a custom PCB will be more compact and have a much better appearance.

This circuit only takes up 1 5/8" x 1 1/4" x 1" and can operate from 8.4V to 31.2V and output maximum of 500V safely.

I strongly recommend using at least a 12V Battery if you goal is maximum power.

This Version's Size can also be reduced to 1 5/8" x 1 1/4" x 3/8" if the Inductor is placed away from your circuit, as it is in most coilguns for convince. Shown in Picture Below.

DANGER HIGH VOLTAGE
This device can put out lethal voltages and the capacitors you charge can store lethal charges for hours, Wear Electrician Gloves and Safety Glasses while operating and take all safety precautions

Specifications:
Project Cost:
- $20 + Shipping Mouser
- $5 + Shipping Coilcraft PCV-2-394-05L (Follow the link and type in the part number to buy)
->=$15 + Shipping MPJA
- Average Total Cost with Shipping
-- <$50--

Input Voltage: 8.4V to 31.2V
Output Voltage Range: 100V to 500V
Output Power:

- TEST 1-12V Input 48W max +-20% Charged 290J Capacitor Bank in 6s
- TEST 2 - 12V Input 45W max +-20% Charged 1160J Capacitor Bank in 26s
- 24V Input TBD

Output Power Measured with 1-2 12V 34Ah Lead Acid Batteries for a Virtually Constant Voltage Source
Each test was done 5 times, the best of which is shown.

The Major limitation of how much power can be drawn from your batteries is the Battery Packs ESR

---For Best results used high current rated batteries or Batteries meant for Power RC Devices---NiCd are the best(with the exception of Li-poly)
For The Following Batteries an Estimated Maximum Power can be drawn
ESR = Equivalent Series Resistance = Internal Resistance

Alkaline can be used, but I strongly recommend Rechargeable high current rated batteries.
Lower Voltages May be used, but expect a Lower Power Output.

NiCD/NiMH
12V AAA ESR = 350-400mOhm 28-30W
12V AA ESR = 150-300mOhm 31-34W
24V AAA ESR = 700-800mOhm 60-80W
24V AA ESR = 300-600mOhm 75-85W

Warning-Drawing too much current from your batteries may reduce there capacity, life, and cause your batteries to overheat, monitor your battery Temperature when testing.

Step 5: PCB Boost Converter 500V Parts

Tools:


Materials:

MPJA or Amazon:


Parts Bought From Mouser:

For C1, C2, C3, and CT use a voltage rating according to this:
Battery Voltage..........Capacitor Rated Voltage

<=12V Bat..............................>=16V Cap
<=20V Bat.........................>=25V Cap
<=30V Bat.........................>=50V Cap

U2- Voltage Regulator - DPAK (TO-252)
Battery Input Part Number

-8.4V to 12V LF60ABDT
-12V to 13.2V LF90ABDT
-13.2V to 16.8V MC7809E
-16.8V to 26.4V MC7812E
-26.4V to 31.2V LM317M (R1 = 500 Ohm R2 = 5.5 k Ohm)

-- C2 Type According to Regulator Used: --
LF60ABDT Electrolytic
LF90ABDT Electrolytic
MC7809E Ceramic
MC7812E Ceramic
LM317M Electrolytic

-- C1, C3, C4, and C5 are MLCC SMD/SMT 5%-20%, or -20% to +80% --
-- CT is MLCC SMD/SMT 1%-10% --
-- All Resistors except for Rdiv1 is 1/10W or greater --

4 Digit Number After Value is Size (i.e. 0805 or 1210)

-C1-10uF 1210
-C2- 10uF 1210
-C3- 0.22uF (220nF) 0805
-C4- 0.01uF (10nF) 0805
-C5- 0.01uF (10nF) 0805
-CB1- Any Capacitor Bank You Wish To Charge
-CT- 0.022uF (22nF) 0805
-LEDPWR- Indicates Power is Applied 1206
-LEDREG- Indicates Desired Voltage is Reached 1206
-LEDGATE- Indicates NE555 is sourcing voltage to the MOSFET 1206
-R1, R2, R3-1kOhm(<12V) or 2kOhm(>=12V) 1%-5% 0805
-RA- 15kOhm (2% or better) 0805
-RB- 10kOhm (2% or better) 0805
-Rdiv1- 1MOhm (2% or better , 1/4W or greater) 1206

-Rdiv2- 0805
Regulator Used Value (2% or Better)
LF60ABDT 11kOhm
LF90ABDT 16kOhm
MC7809E 16kOhm
MC7812E 22.3kOhm
LM317M 28kOhm

-SW1- Rated for greater than input voltage at 5-6A

-U1 and U1.1(Same Chip) - LM393AM SOIC-8
-U3- SE555D SOIC-8
-VR1- 10kOhm Potentiometer (Multi-turn will be more precise)

-M1- FCA47N60(F)
-D1- RURG3060 (Please use the RURG30120 if this is one of your first electronic projects)

Coilcraft:
-L1- Coilcraft PCV-2-394-05L (Follow the link and type in the part number to buy)

PIN NUMBERS ARE ON THE SCHEMATIC
CLICK THE " i " AT THE TOP OF THE SCHEMATIC FOR A LARGER DOWNLOAD ABLE VIEW

Step 6: PCB Boost Converter 500V Construction

The First Step in PCB construction is to design your PCB Board using DipTrace (click the link and download the DipTrace 2 freeware)

You can also use the PCB Layout Shown in the Pictures Below.

The Next Step is to get the Design onto the PCB, you can do this two ways: Using a Laser Printer (Fast, Easy, and if you can find one to borrow I recommend it) and Hand Tracing (VERY TIME CONSUMING)

- LASER PRINTER -

INK JET PRINTERS WILL NOT WORK

USE THIS LINK TO LEARN HOW TO MAKE A PCB BOARD

Tools:

  • Copper Clad
  • Industrial Grade or Resist Permanent Marker (Industrial Grade Sharpie Can be found at Lowes)
  • Iron / Ironing Board
  • Etchant (Ferric Chloride)
  • Any Leak Proof Multiple Lock Seal Plastic or Glass Container (Example)


If you happen to have a Laser Printer simply get some catalog, phone book, or newspaper paper. This is the type of cheap paper that is very light and most importantly falls apart in water, test a piece of paper in water to make sure. You'll need to tape the paper to a regular printer feed sheet (Shown In Picture Below) You only need to tape it to the top of the sheet, make sure it is as flat as possible to the printer sheet so that when it is feed through the printer it does not crumple.
Download the File Below ( Boost Converter, SMT2 )( You will need to Download the DipTrace 2 freeware). Open the File and click Print Preview Under FILE. Make sure the Objects Selections are as shown in the Picture and the Mirror Box is checked. Click Print, In the Print Window select Properties. In the Properties window select the graphics tab and In the Darkness Square select DARK.
Feed the Paper with the cheap paper taped on it into the printer and Click Print.
Your Paper should look like in the 5th Picture. Use this to size your PCB and cut your Copper Clad with a Dremel or table saw, cut slowly.

Turn on your iron on and put it on it's highest setting ( usually Cotton ), Wait for it to heat up...
While waiting thoroughly clean your copper clad piece with hot water and soap, thoroughly dry your piece. When your iron is finally heated place your copper clad on an ironing board with the copper side face up. Cut the LASER printed Layout so that it is the size of the copper clad piece. Place the piece of paper toner side down and place the iron flat down on the paper and copper clad. Push down with moderate force and wait a few minutes. The copper clad and paper should now be stuck together. Place the piece, it will be HOT, into a container of warm soapy water and wait five minutes.
After waiting take the Piece and run it under warm water and gently rub the top of the paper until all that is left is the toner. Touch up the Layout with your permanent marker.
GO TO NEXT STEP

- HAND TRACING -

- Copper Clad
- Etchant
- Industrial Grade or Resist Permanent Marker (Industrial Grade Can be found at Lowes, hard to find you may have ask where it is, if you find it somewhere else let me know so I can post it)
- Plastic Container

Print out the 6th picture large scale, use your parts as references and draw the traces with your permanent marker as best you can. This will be tedious so be prepared to spend several half hours doing even simple traces.
Seems Simpler huh, It's not.

GO TO NEXT STEP

Attachments

Step 7: Final Issues

Below is a picture of how to charge multiple bank so that if one is discharge the others will not.