Boosting my boost module

[netdudeuk]

Hi

I'm using one of these for a Nixie clock project -

https://www.ebay.co.uk/itm/264785680757

Without a load, I can tune the output to get 180v.  However, when I apply the load (the tubes), the voltage drops down to about 150v.

The tubes still work ok but maybe a little dimmer than I'd like.

This may be because I'm running everything at 5v with the boost module officially needing a little more (9-12v) to go beyond the 150v.

If I use a longer USB cable for the power, the voltage drop below is clearly measurable and the boosted voltage is even less.  The tubes don't get enough to work at this point.

Is there a cheap / simple way with a few discretes to get an extra volt or two from the 5v to keep the boost module happy ?  Having to add a separate proper 12v supply would just make the whole project unwieldy.  Or even would one of these be enough ?

https://www.ebay.co.uk/itm/DC-DC-MICRO-USB-MT3608-Voltage-Step-Up-Adjustable-Boost-Converter-Module-UK/193540866970?hash=item2d0fef439a:g:lEwAAOSw8Sde2hCf

Thanks

[EEauroro]

Can you use USB-C (with a USB-C charger/source) ? If yes, you can use the power delivery feature in USB-C to give you the voltage that you need. You will need a dedicated IC to handle the power delivery request. If you cannot do it on your own, you can buy off the shelf modules that will do this for you:

https://www.tindie.com/products/clarahobbs/pd-buddy-sink/

PD Buddy Sink is a smart power jack for USB Power Delivery. Configure it with the voltage and current your project needs, then plug it into any USB PD power supply with a high enough power capability. It negotiates with the power supply and turns on its output, giving your project up to 3 A at 5, 9, or 15 V, and up to 5 A at 20 V

[ledtester]

The MT3806 module might work.

The ebay listing of the high-voltage module has this chart:



In order to get 220V output it says you need to supply it 0.5A at 9V.

Assume that the MT3806 module is 80% efficient. If you feed it 5V at its input, it needs

  0.5*9/5/0.8 = 1.125 A

of current to output 0.5A at 9V.

Can you get that much current from your 5V power supply?

With a lot of these ebay power modules, the only way to find out if something is going to work is to just try it.

[VEGETA]

I think you can add a pass transistor to your module to increase current output since drop voltage is caused by limited current supply.

another solution is to use 2 boost modules in parallel but using the same feedback setting potentiometer. this is not so recommended but still can deliver results.