Datasheet · 2021
Bill of materials, parts placement drawing and port list (2021-08-09). Note: BOM omits R11, R33 and C16, and the drawing shows K46, which the later 54-relay board drops.
RL1200 – 4-digit 12-hour nixie clock 1 2021-08-09 Bill of Materials Part Value Description D1-D22, LED 3mm T-1 LED D24-D27, D29-D33 D23 IN4148 D28, D34 BAV21 K1-K55 G2R-2-12VDC DPDT relay J1-J6 Header 0.1” pitch header, right angle recommended C1,C2, 470uF 16V 5mm diameter, 2.5mm pitch electrolytic C4-C8, C10, C11, C14, C15 C3 33pF 16V 2.5mm pitch ceramic C9 100pF 16V 2.5mm pitch ceramic C12 680pF 16V 2.5mm pitch ceramic C13 100uF 16V 5mm diameter, 2.5mm pitch electrolytic C17-C20 0.1uF 16V 2.5mm pitch ceramic L1 100uH 1A Axial inductor 15mm pin pitch, 4mm diameter Q1, Q3 IRF630 Power MOSFET Q2 2N3906 PNP transistor R1, R2, R8, R9, 10 ohm 1/4W Storage relay inrush limiting resistor R13, R30-R32, R52, R53 R3, R10, R12, 10K 1/4W LED current limiting resistor R14-R16, R21R29, R34, R35, R39-R42, R46R51, R54, R57, R58, R61 R4 2.2Meg 1/4W R5, R6, R17330 ohm 1/4W Storage relay holding resistor R20, R36-R38, R59, R60 R62-R65 33K 1/4W Nixie anode resistor R7 2.2K 1/4W R43, R44 0.5 1/4W Nixie power supply current limiting resistor R45 1K 1/4W R55 470K 1/4W R56 3.8K 1/4W Nixie power supply feedback control resistor SW1,SW2 SPDT switch 3 pin 4.7mm pitch U1 CD4521 Clock IC U2, U3 CD4017 Decade counter/divider IC U4 MC34063AP Nixie power supply controller Y1 4.194MHz Crystal for CD4521 timebase Mount holes are 4mm (#8 screw) diameter. 2 2021-08-09 “POWER IN” Input Ports Name Size Description +12V 1 Power supply 12VDC GND 1 Power supply ground “EXT IN” Input Ports Name Size ~CLK 1 GND 1 Output Ports Name Size 1 MIN 11 10 MIN 7 1 HOUR 11 10 HOUR 3 3 Description Active low external 1Hz reference (optional in lieu of timebase ICs) Signal ground Description 0-9 digit output (active low) + anode 0-5 digit output (active low) + anode 0-9 digit output (active low) + anode 0-1 digit output (active low) + anode 2021-08-09