This is the second video in a series of three, on how to get started with the DRSSTC UD3 Tesla coil driver. In this video I go through which hardware parts to change, how to configure the UD3, update firmware and use TeslaTerm to control and troubleshoot on a DRSSTC. In the end, I will be installing this in my large Kaizer DRSSTC 3 Tesla coil!
If you missed the previously part 1, check it out here: https://kaizerpowerelectronics.dk/teslacoils/nextgen-drsstc-ud3-unboxing-soldering-startup-and-software-part-1-of-3/
Huge shoutout to Steve Ward, Netzpfuscher (Jens Kerrinnes), Malte0811 and TMaxElectronics (Thorben Zethoff) altogether for their work on the UD3 platform.
UD3 Test and Installation
The DRSSTC 1 used in the part 2 video, uses a full bridge of SKM200 IGBT half-bridge bricks. The small red numbers on the schematic, refers to the terminal numbers of the SKM200 IGBT brick. GDT1 A and B, GDT2 A and B, refers to the UD3 schematic. Firstly GDT 1A is on channel 1 of the oscilloscope, through a differential probe. Secondly GDT 1B is on channel 2 of the oscilloscope, through a differential probe. Thirdly GDT 2A is on channel 3 of the oscilloscope, through a differential probe. Fourthly GDT 2B is on channel 4 of the oscilloscope, through a normal 10x probe. Differential probes are needed, to avoid short circuit of the full-bridge through the ground clips of normal probes.
GDT 1A and GDT 2B (channel 1 and 4) needs to be identical. GDT 1B and GDT 2A (channel 2 and 3) needs to be identical. These two sets of driving signals have to be of opposite polarity, in order to switch current through the load, at alternating polarity.
The UD3.1 PCB design has a few important differences from the UD3 PCB. JP12 + JP14 have to be soldered together, to activate Vdrive voltage to the output stage for the GDT. As the UD3.1 has the possibility to adjust the Vdrive voltage. Input for DC bus voltage sensing and DC battery voltage sensing seems to be switched around between the UD3 and UD3.1 PCB.
The presently installation of the UD3 in the Kaizer DRSSTC 1, there is no more room, as the UD3 required a larger enclosure. DC bus voltage sensing is done with two 700K resistors, for a maximum of 700 VDC measurements in TeslaTerm. DC bus current is measured with a Honeywell CSNS300-001 current transformer hall effect sensor. Make sure to calculate the maximum developed output voltage, from the shunt resistor and supply voltage.
UD3 Information and Links
- 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)
UD3 github: https://github.com/Netzpfuscher/UD3/wiki
TeslaTerm github: https://github.com/malte0811/Teslaterm
FiberNet github: https://github.com/TMaxElectronics/UD3_Fibernet
UD3.1b github: https://github.com/TMaxElectronics/UD3.1