Android APP Contact Us
login / register Upload Project
TRENDING:

HV Nixie DC-DC Switching Power Supply

socialicon

Nixie tubes need about ~180Vdc to light up and thus on most devices, a DC-DC converter is needed. Here we designed a simple DC-DC switching regulator capable of powering most of Nixie tubes. The board accepts 12Vdc input and gives an output of 150-250Vdc.

Description

The module is based on the MAX1771 Step-Up DC-DC Controller. The controller works up to 300kHz switching frequency and that allows the usage of miniature surface mount components. In the default configuration, it accepts an input voltage from 2V to Vout and outputs 12V, but in this module, the output voltage is selected using the onboard potentiometer and it’s in the range 150-250Vdc. The maximum output current is 50mA @ 180Vdc.

The MAX1771 is driving an external N-channel MOSFET (IRF740) and with the help of the inductor and a fast diode, high voltage is produced.

MOSFET has to be low RDSon, the diode has to be fast Mttr, typically < 50nS, and capacitors have to be low ESR type to have good efficiency.

Precautions must be taken as this power supply uses high voltages. Build it only if you know what you are dealing with. Don’t touch any of the parts while in use.
Pay attention on the placement of C1 tantalum capacitor, as the bar indicates the anode (positive lead)

Schematic

Parts List

PartValueLCSC.com
R11.5M - 0805 SMDC118025
R310k 0805C269724
R45k trimmer SMDC128557
Rs0.05 Ohm - 0805 SMDC149662
C1100uF Tantalium SMDC122302
C2, C3100nF - 0805 SMDC396718
C44.7uF / 250V SMDC88702
C5100nF / 250V SMD 1210C52020
ICMAX1771 SO-8C407903
L1100uH / 2.5 AC2962892
Q1IRF740 D2PAK (TO-263-2)C39238
D2ES2F-E3, ES2GBC145321, C2844160
X1, X2Screw Terminal - P=3.5mmC474892

Oscilloscope Measurements

Yellow is the MOSFET Gate voltage and Green the output high voltage (~180Vdc). We see that the transistor switches with a low frequency of 146Hz and with a peak gate voltage of 12.8V
zoom in to the above short pulses reveals 3x pulses with 48.7Khz frequency to the gate of MOSFET. Also, the peak to peak ripple on output is 6V
further zoom to the output ripple reveals some short ringing and the peak ripple voltage.



Efficiency

The module’s efficiency is calculated for two output currents (50mA and 25mA) at 180Vdc voltage output and 12V input. In the first case, the Pout = 8.1W while the Pin=10.96W, so efficiency is calculated at 73.9%. In the second case, the Pout = 4.1W while the Pin=5.52W, so efficiency is calculated at 74.2%. We see that for lower currents efficiency is a little greater than for the maximum current of 50mA.

Gerber View

Photos

If you would like to receive a PCB, we can ship you one for 6$ (worldwide shipping) click here to contact us

MAX1771 Datasheet

MAX1771

PCB

JLCPCB - Only $2 for PCB Prototype (Any Color)

24 Hours fast turnaround, Excellent quality & Unbeatable prices

$18 Welcome Bonus for new registrations Now https://jlcpcb.com

Downloads

Subscribe
Notify of
guest

37 Comments
Inline Feedbacks
View all comments
Francois

Hi, what is the nominal and or maximal output current @ 180V ?
And you say that i can be powered from 2, to 16.5V. Is it really 2v or 12V ?
Thank you !

0
Reply
mixos

It can be powered from 12V to 16.5V. This is fixed in paragraph.

0
Reply
ZF

Poor Layout

-3
Reply
Dustin Williams

where is your design ZF

1
Reply
mixos

Design is completely updated. Thanks

0
Reply
Julian Lützen

I think it’s better to have more clearance to GND at the HV Output at the bottom side of your PCB. It seems there is a distance of less 1mm to GND. I would let end of the GND polygon about 1cm before the HV Connector and connect the HV-GND Pin with a single strip to the polygon. It feels a bit safer this way.

0
Reply
mixos

Thanks for your input. I agree with you and i will take this into consideration for the next version. If you are familiar with EAGLE, you can do this fix and share with us?

0
Reply
spvoile

Hello, I am not an expert in mosfets but I wanted to know if I can replace the IRF740ASTRLPBF with IRF740STRLPBF (same reference without the “A”). The datasheet is quite similar and I don’t know if the difference matters for this application…

0
Reply
mixos

Yes, you can use it, as the basic characteristics are the same.

0
Reply
Yodee

Hello!

I would like to use this project, but I can’t open the eagle file. It is corrupt. Can You help me?

Thanks

0
Reply
mixos

I’ve updated the zip file with eagle files, could you check again ?

0
Reply
Yodee

Unfortunetly still wrong. Eagle 7.6 and EasyEDA still can’t open the .brd file.

0
Reply
mixos

What error did you get?

0
Reply
Yodee

In EasyEDA when I try to import the .brd, it says:

“Unexpected error while converting. Perhaps unsupported file type or program bug”

Can You open it in EasyEDA?

0
Reply
mixos

You should use Autodesk Eagle to open the files, It seems EasyEDA doesn’t support this file type.

0
Reply
Yodee

It works! Thanks!

0
Reply
Yodee

Mike!

Can this power supply do 180V 30-35mA with 12V in?

0
Reply
mixos

Sure, it goes up to 50mA @ 180Vdc

0
Reply
Yodee

And What about heating?

0
Reply
mixos

This is a high-efficiency switching regulator and for that input/output, i don’t think it will heat up at all.

0
Reply
Yodee

Perfect. The PCB already here, i waiting the components. I hope it will be good for me.

0
Reply
Yodee

Dear Mike! I set up the power supply.On my 6 tube nixie clock the values are this:

In the morning, when 5 tube is in work (0:00 – 9:59) the current is 15-18mA @ 180V
After that (10:00-23:59) when all the 6 tubes are in work the current is 19-22mA @ 180V. The Induction is getting hot. Is this normal, or i make something wrong?

Thanks

0
Reply
mixos

How hot does it get? Can you measure it?

0
Reply
Yodee

~50°C in 30 minutes

0
Reply
mixos

I think this is normal for output like that. If you would like to be on the safe side, you may replace the inductor with a bigger one.

0
Reply
Yodee

Which type / size?

0
Reply
pcbbc

Just to say thanks very much for providing this design and the parts list.
I’ve now completed my FLW project that I purchased the tubes for back in 2016.
Two of these circuits on the PCB driving 2 B-7971 tubes each.
Almost 180V right out of the box because the 5K trimmers were supplied centred. Nice!

1
Reply
sebastian simone

Hi, I have a module similar to this and I’ve got a question: How would you fix this to the chassis when using the module? This and other similar implementations of HV SMPS commonly don’t have holes for separators. Any Ideas?

Thank you

0
Reply
mixos

Yes, right, this is to reduce the overall board size. You can mount it on a chassis using double-sized tape.

0
Reply
Dishy

Hi, I am curious if I can use a more low voltage, high amperage 3.7v Li-Po to power this. Is there change I have to make with the schematics?

0
Reply
Robert

Hi,
How do you increase the output current for this?
(say I want it to give me 80mA)

1
Reply
Ferran

Hi! Thank you very much for sharing your project.
I was wondering which criteria have you followed in order to choose the inductor inductance and wether it is working in continuous or discontinuous current mode. I also felt curious on how did you decide Rsense value. Maybe using datasheet’s graphics?
Thank you very much once again.

1
Reply
mixos

This board is heavily based on this one Nixie HV Switching PSU: https://desmith.net/NMdS/Electronics/NixiePSU.html and the calculations based on datasheet.

1
Reply
Leon

Hello,
I would like to know whether the HV Nixie DC-DC switching power supply is RoHS compliant?
Thank you!

0
Reply
mixos

Sorry, this is not RoHS compliant.

0
Reply
Adam

Awesome. Could be customized to have the SHDN for turning off the power supply/ HV output

0
Reply
mixos

How many boards do you need ?

0
Reply

RELATED PROJECTS