Steps to solder components in order for Nixie7 ____________________________________________ Please look the board over carefully and read the instructions and parts list to familiarize yourself with the assembly procedure before you begin. Please also familiarize yourself with transistor orientation: looking at the front (flat side), the three leads are, left to right: emitter, base, collector. A diode has a + and - side, and IC's are marked on one end with a small indented "notch". The IC sockets are also notched. Electrolytic (cylindrical shape) capacitors have a + & - side . Solder all components on the bottom of the board (if possible). For transistors, I find it helpful to let the transistor stand up above the board rather than pushing the leads all the way through; this lets the transistor chip inside the case standoff from the heat of the soldering iron. I also find it helps to solder one lead at a time, pausing in between to allow the transistor to cool for a minute. This also applies to the leds, particularly the RGB leds, which are sensitive. Part 1 : The high voltage ---------------------------------------------------------------------------------- Solder components in this order: Transformer - Primary side is next to fuse, solder leads to the top as well as the bottom. Fuse Four pin jumper - solder to the square marked with 240VAC/120VAC - only necessary to switch between 120VAC (U.S.) and 240VAC (some other countries) - If this is not necessary, you may solder a small jumper to the appropriate holes (120 or 240) to make a permanent connection. R1 - 220 ohm, 1/2 watt resistor. R44 - 1 Meg ohm C3 - 2.2 uF, 350V capacitor R43 - 220K resistor neon bulb D1 - 1N4007 diode NOTE ORIENTATION D2 - 1N4007 diode C2 - 2.2 uF, 350V capacitor white wire to NEUTRAL black wire to HOT Connect these to an AC power cord, and plug in. Neon bulb should light. Test for high voltage at GND (negative) and ~300VDC (positive) (C1 negative & Q2 emitter) Part 2 : The low voltage ---------------------------------------------------------------------------------- B1 - rectifier bridge, note orientation R40 - 100K resistor C4 - .01 uF ( 103 ) cap C1 - 1,000 uF 35V electrolytic cap D3 - 1N4001 diode R42 - 10K resistor Q1 - 2N3904 NPN transistor R41 - 1K resistor Attach the heat sink to the regulator, using the insulating pad & washer. 7805 - 5V regulator D4 - 1N4001 diode R45 - 470 ohm resistor LED - 5VDC indicator (Red) Plug the power cord in, and the neon light & led should light. Part 3 : The logic components ---------------------------------------------------------------------------------- In this step, it is a good idea to let the resistors stand off a tiny bit from the board, 1mm is enough, just to ensure there will be no leakage of the high voltage from the trace under the resistors to that resistor. U1 - 40 pin wide IC socket - ORIENT CORRECTLY R6, R7, R9, R10, R48 - 2.2K resistors S1 - Slow set button S2 - Fast set button S3 - LED color button S4 - Toggle button R3, R15, R30, R35 - these are 47K resistors. R8, R11, R2, R12, R13, R14, R18, R19, R20, R24, R25, R26, R27, R28, R46, R32, R33, R34, R39 - these are 33K resistors R21 - 100 ohm resistor R4, R16, R22, R47, R36 - these are 470K, don't solder the double hole side until the 100K resistors are inserted. R5, R17, R23, R31, R37 - these are 100K, now solder the side adjoining the 470K's R49, R50 - 120K resistors. Q24, Q25, Q3, Q22, Q23, Q20, Q18, Q19, Q16, Q14, Q15, Q13, Q12, Q10, Q11, Q7, Q4, Q5, Q3 - these are all MPSA44 NPN (or KSP44) transistors. Q2, Q21, Q17, Q8, Q2 - these are all MPSA92 PNP transistors. Q2 was mistakenly marked twice; both are valid. Five pin socket for the wifi (or gps) module. Now, test the digit drivers by plugging the cord in; there should be about ~300VDC to the board's drivers. At this point, all the anodes of the tube socket holes should read 0VDC. Use a jumper wire to connect pin #32 on U1 to pin #33, then test for high voltage at the anode hole of the first nixie space. This is the one on the right when looking at the front of the board (ones minutes count) This should read about 285VDC relative to ground (0VDC) or pin #31 on U1. Do the same after connecting pin #32 on U1 to pin #34, and test for HV at the second anode hole. Connect #32 to #35 and test for HV at the colons solder points, which are marked with a small circle. Continue to the next (third anode hole) by connecting pin #32 on U1 to pin #36. Next connect pin #32 to pin #37 and test for HV at the fourth anode hole. Disconnect power and remove the jumper wires from the IC socket. Carefully insert the IC into the socket, noting proper orientation. You should now be ready to begin soldering in your nixie tubes. Part 4 : The Nixie tubes, colons, RGB leds ---------------------------------------------------------------------------------- The best way I have found to solder the pin sockets in place is to place them over the pins on the nixie tube and then align them & insert into the holes marked on the board. The neon bulbs are used for colons, they are soldered to the single strand wires and inserted into the test tube, and the wire ends are soldered into the holes inside the area marked for them on the board in between the nixies. The solder points are marked with a small circle. The RGB leds can be added before or after. I place these after soldering the nixie pins in place. The led can stick up to the very bottom of the tube for best affect. There are four solder points under each nixie to solder the leds to. They are marked with R, G, B for anodes and K for the cathode.