Aug 23:  on third transformer as I gradually increase the wattage

Board on wall continuing lifetime test.

 

 

 

 

 

 

9VAC  800mA

too small

 

 

 

 

 

 

12VAC 1A

still too small

 

 

 

 

 

 

12VAC 1.66 A

gets hot but may work....

 

 

 

 

 

 

Aug 1: The high voltage supply has been tuned and is supplying 160 Volts driving 6 Nixies and 4 neon lamps.

 

The switcher case is running at 172F, the die can't be more than 175F, the max temp is 300F, so the heat sink seems sufficient.

 

This board will be run continuously as a lifetime test.

 

This board will not be a kit, is an abomination to me, it mixes technologies of different eras, but it is a good test of the discrete switching supply.

 

Next, I need to update the transistor clock with an additional flip-flop for day/night to allow for jumpering of hours to switch off the display.  Also I intend to add 50/60 Hz jumpering to the kit to help the non US builders.

 

 

 

 

 

July 17: The test board is loaded and mostly working.  The power supply needs some adjustments to raise the power delivered at 200 Volts.  It droops and barely lights the displays.  The inductor current will be raised to about 2 amps.  I am awaiting parts from digikey.

 

Following that, a final layout using the transistor clock circuits, the HV supply and the Nixies will be attempted.  I hope to keep it to about the same size as the transistor clock and also add jumpering for 50/60 Hz options.

July 12: 2nd test board partially loaded and original power supply connected.  This tests the PIC circuitry and program.

 

The purpose of this board is to test out the high voltage supply for a full load and to test the NIXIE socket footprints.  Note the NE-2 bulbs are too bright, the current will be lowered.

 

Next step -> load the HV supply and run with 6 Nixie displays

 

 

Note: this board is just a test board, it has ICs and even a surface mount component on it.  The final kit will have only 1950's parts on it.  (although it will have a TO-220 transistor.  It shoud be a TO-3 part, but they are too expensive, pity)

 

After I get this board running, I will take the transistor clock layout and put the Nixie displays and HV supply on it for the final kit.

 

June 15: Nixie test board loaded and PIC is cycling thru digits -  see the movie ->

 

June 6: High Voltage supply board running

 

 

9 volts in - 190 Volts out.  Note the NE-2 neon bulb glowing on the lower right.

Upper trace: 50 Volt/div

Lower trace: 5 Volt/div on a .5 ohm so 1 Amp/div

Timebase: 20uS per div (showing about 8KHz)