Nixie Wrist Watch, 4 Digits

This project is about making a 4-digit nixie wrist watch.
https://youtu.be/MAw0OgJxuy0

Supplies:

small size nixie tubes (4)
Arduino pro mimi

IC 7805
IC 555
IC 74141 (or 7441)
MPSA42 Transistors (5)
MPSA92 transistors (4)
RTC module DS3231
IRF740 mosfet
UF4007 diode
33 kohm resistors (5)
22 kohm resistors (4)

100 kohm resistors (5)

10 ohm resistor
1 kohm resistor
10 kohm resistors (4)

470 kohm resistors (4)

5 kohm potentiometer

100 nF 600V capacitor

100 pF capacitor

2.2 nF capacitor

100 uH 1A inductor

Lithium polymere batteries 300 mAh (2)
On/off switch
Push buttons (2)
Female jack (smallest size)
Charger adapter (8.4 volt, 1A)
3D printed case
Watch straps

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Specifications

With the schematic circuit offered here, the watch can run at least one hour in continuous display on.
Accuracy is better than one second in a year.

Step 2: Construction

Try to use smallest components that is available (smd is preferred).
The RTC module must be very small size.
Assemble the parts on "air" to reduce the space.
More technical explanation on driving nixie tubes is available in my previous instructable (6-digit nixie clock)
https://www.instructables.com/id/6-Digit-Nixie-Clock-Timer-Thermometer/

Step 3: Important Note on Charging the Batteries

In order to minimize the components and size, I have not included a charge control in the design. If the batteries are fully discharged, use 8.4 volt charger for about 4 hours (display off). Disconnect the charger after complete charge to avoid damage to the batteries.

Be the First to Share

    Recommendations

    • CNC Contest

      CNC Contest
    • Make it Move

      Make it Move
    • Teacher Contest

      Teacher Contest

    Discussions

    0
    None
    randofo

    6 weeks ago

    That's cool looking. Nice job.