Skip to content

Home

Jump to bottom
MadsBarnkob edited this page Jul 11, 2024 · 10 revisions

ud3

The UD3 is a Tesla coil driver board for controlling a DRSSTC or QCW. The interrupter is embedded in the UD3 (Classic Mode / MIDI / SID(C64) / QCW Ramp). The UD3 was originally developed by Steve Ward.

Features

  • Embedded interrupter with MIDI and SID audio modulation
  • Primary resonator fres measurement (frequency sweep)
  • Primary peak current measurement over feedback CT
  • Pulse skipping
  • Alarm/Event system for fault tracing
  • System fault interlocks for undervoltage/temperature/watchdog
  • Bus current measurement (current or voltage mode CT)
  • Controls up to 4 relays to handle inrush current and other things
  • Can control an external light display for showing selected parameters
  • It runs FreeRTOS, making it easy to add new functionality
  • Commandline over serial interface
  • Multi user commandline over MIN-Protocol
  • Dual voltage measurement (differential)
  • Support for Teslaterm and UD3-node
  • Telemetry over serial
  • Bootloader with serial/usb support (firmware update with Teslaterm)

Support

Join the UD3 community Discord server for support and collaboration. Discord

Useful links

Getting started

  1. See Build Notes for tips on building the UD3.
  2. Flash the firmware
  3. See the Testing page for some things to check to verify operation.
  4. Connect the UD3 to your coil
  5. See the reference pages for a list of available commands and parameters.
  6. Make sparks (the good kind)

Pinout for the Impatient

Pinout

Commands for the Impatient

After flashing connect to the USB-Port and connect to the virtual serial port with a VT100 terminal like putty.

Configure your serial connection. The default baudrate is 460800. It is sufficient.

If you want to connect to Teslaterm or UD3-Node you need to enable MIN:
set min_enable 1

You need to have a feedback transformer which results in round about 1,5A at absolute peak current. Setup your feedback current transformer (CT1) example: 1:1000
set ct1_ratio 1000

Setup your DC-Bus current transformer:
set ct2_ratio 1000

Enter the maximum current for transient mode (DRSSTC):
set max_tr_current 600

Enter the minimum current for transient mode only used for MIDI modulation (DRSSTC):
set min_tr_current 100

Enter the maximum current for qcw mode (QCW):
set max_tr_current 300

Enter the maximum pulsewidth and repetition rate (us/Hz):
set max_tr_pw 400
set max_tr_prf 800

Enter the lead time (ns) around 500ns for small bricks and around 1000 for big bricks:
set lead_time 1000 (Test)

Make a autotune, connect everyting and give your coil a little bit bus voltage (around 40V-60V):
set tune_start 30 (kHz for sweep start frequency)
set tune_stop 100 (kHz for sweep stop frequency)
bus on
tune prim

The coil sweeps through the given range and finds the resonant frequency. This frequency needs to be set in the start oscillator: set start_freq 54.4 (in kHz)

Save everyting in the EEPROM:
eeprom save

If you have enabled MIN, you need to restart your coil [reset]. You can test everything with the transient mode:
set watchdog 0 (to disable watchdog)
kill reset (to clear all faults)
tr start
set pw 30 (for 30us ontime)
set pwd 2000 (for 2000us period)
tr stop (to disable transient mode)

Acknowledgements

This is the firmware for the UD3 Teslacoil driver. It is originally developed by Steve Ward.

Many thanks to all of the open source software libraries used in UD3!

Clone this wiki locally