by Bob Coggeshall / cogwheel.com
Mr. Coggeshall contacted my via the Facebook page to direct me to his website and I really wanted to show off his work. (This is the first of two posts on his work.)
Mr. Coggeshall has developed a driver that can power up to seven B7971 tubes and is primarily driven by a computer. One other feature that I have not seen elsewhere is that it establishes a serial connection over Bluetooth. This enables the owner to place the device some distance from the computer without having to run cables.
The Cogwheel model 301x is a versatile Nixie tube clock driver board. Its features include
- Drives tubes located on a separate board to accommodate a variety of tubes and custom enclosures.
- Drive capability for up to 7 tubes with up to 14 cathodes each;
- Supports classic “0 through 9” numeric tubes as well as large segmented alpha-numeric tubes such as the B7971.
- Symbolic tubes and individual neon lights can also be driven.
- Stable, modern design utilizing surface-mount components.
On board features include:
- Flash-upgradeable processor (Microchip PIC16F877)
- Non-volatile configuration memory
- Adjustable high voltage generator fully controllable by processor.
- Non-volatile clock chip (Dallas/Maxim DS1302) with capacitor backup for maintaining time for up to 12 hours across power outages.
- RS232 Serial Interface – Can be interfaced to a GPS receiver, personal computer, or other device.
- 1 pps (pulse per second) TTL level input for incrementing time from external source (GPS receiver or other equipment).
- Cool-running 5 volt switching power regulator – Can supply up to 500ma of power to an external device such as a GPS receiver.
- Infra-red receiver interfaced to a secondary processor (Microchip PIC12F675) for control
- AC powerline frequency can be sampled by processor Runs on AC(9-12V) or DC(12-15V) power
Latest software release features include:
- Complete Hours, Minutes, Seconds, Year, Month, Day timekeeping
- Configuration via buttons, infra-red remote, or serial command interface
- Configurable synchronization source - Non-volatile real-time clock, GPS, or serial
- Configurable time increment source – Internal, 50/60 Hz AC Power, or 1 PPS input
- Optional Daylight Saving Time Correction (North American rules)
- Per-digit transition fading effect
- Smooth transition between HHMMSS and YYMMDD displays
- GPS – Display blinks if GPS does not have a fix
- GMT offset to convert GPS time to local time