Looking for advice on building a DT-1704C clock

[Dylan Distasio]

Hi folks-

I've accumulated a few DT-1704C VFDs over the years.  Although I would rather have Y1938s with their blue tint, I also really like these tubes.  I was thinking of either handwiring a prototype or trying my hand at spinning my first PCB, but was looking for suggestions on a power supply IC (or other options).

The segment voltage is 27V, and the filament is 1.6V.   I was thinking of using 12VDC in, but am still a noob when it comes to designing power supplies.  Is there any type of step up/step down IC someone could recommend that would be good for outputting both of those voltages?  

Thanks,
Dylan

[gregebert]

Lots of high-quality free PCB tools out there, and plenty of inexpensive good-quality PCB manufacturers on Ebay.

I stopped breadboarding years ago (and will never go back..) because PCB costs are on-par with breadboarding, and much higher quality.

If you plan to make 2 or more boards, PCBs will save you time and money versus breadboarding.

OSH Park is excellent for small boards ( $5 US per square inch, you get 3 boards)

Laptop power supplies are pretty cheap & efficient. Most comply with a variety of safety standards.

Still, I'm stubborn and design my own because I enjoy the challenge, running simulations, etc.

If you decide to do your own power supply, do your homework for heat dissipation, ripple-voltage, RMS current in the electrolytic caps, spacing and width rules for PCB traces.

Could be very bad if your clock catches fire after several years.

[SWISSNIXIE - Jonathan F.]

A step-up for this voltage (12->27) should be fairly easily to make, a generic MC34063 would do fine, or any other if you care about efficiency.

For example lookt at the LT8330
http://cds.linear.com/docs/en/datasheet/8330fa.pdf

On page 18 you can find a design for a 12V to 24V, you easly can reach 27 by just adjusting the feedback resistors.

For the 1.8V a normal LDO would do, but this would create heat, so i suggest using a heatsink.  Or look at dc-dc desings for 1.8V (since 1.8 is a more used voltage, and most regulators can be adjusted)