Project log: M103v2 mixed-mode modular power supply - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: May 04, 2016, 07:32:43 pm
content: I have been asking a lot of questions about this project, but not once released any information about it in one place. So here is the write up.Specifications (system backplane K103v2-K)Mains input: AC 60-265V 30-85Hz.Power factor corrected to 400V, 250W maximum.All primary channel jacks are defined by modules installed.All primary jacks are isolated, fused and MOV protected.Primary module output limit: 50V, 10APrimary module interface: 2x 36-pin PCIe x1 style card edge connector (one on each side of the transformer,) one daisy-chained 400V supply conductor.Mains-side card edge connector: HV return, gate drive supply (18V.)Low-side card edge connector: module output, module output sense, module output return, module output return sense, next module slot output sense, next module slot output return sense, secondary +5.3V rail, secondary rail return, non isolated 5V I2C bus, bus identification jumpers.Secondary rail: 5.3V trimmed, 3A maximumAdditional module slot: UART interface module.Specifications (digital control board K103v2-D)Microcontroller: ATmega128 or ATmega1281 or ATmega2561 (pin-to-pin compatible with each other) at 16MHzBackplane interface: power, power return, non isolated 5V I2C bus to modules, UARTUser interface: 20x4 HD44780-compatible LCD, 4x4 keypadConnectivity: Bluetooth 4.0 Low EnergyApple-compatible device charging portControl protocol: GICP/mSTKPSpecifications (mixed-mode output modules K103v2-10M3010/100 family)Voltage: 0-30V, 10-bit resolution.Current: 0-10A, 10-bit resolution.Power cap: 100W software enforced. Absolute maximum power not specified.Automatic thermal protection.Topology: output-tracking forward converter, followed by BJT linear regulator.Output noise: 10mV or 1‰, whichever is higher.Optional remote output sensingMicrocontroller: ATmega328P at 16MHzADC: built-inDAC: TLC5615Reference: ADR03BOnboard I2C and digital power isolation.Specifications: (switch-mode output modules K103v2-10S3010/100 family)Identical specifications as K103v2-10M3010/100, except topology and output noise.Output noise: 250mV or 5%, whichever is higher.Topology: forward converter.Specifications: (USB interface K182v2-E1)Based on M182v2 isolated USB to UART interfaceUSB chipset: WCH CH340G at 12MHzOptional Arduino-compatible device resetIsolated UARTSpecifications: (RS232 interface K103v2-R2)RS232 chipset: MAX232Optional Arduino-compatible device resetIsolated UARTDesign goal:* Use as many surface mount parts as possible, but avoid packages that cannot be hand soldered reliably.* Compatible with most commodity computers with no special hardware support: restrict connectivity to whatever an Apple MacBook Pro have, and allow an unmodified Apple iPhone to connect.* Strike a balance between cost and performance.License to all schematics and source code: 3-clause BSDL. Board artwork are not open source.

author: technix
author_rank: Super Contributor
timestamp: May 06, 2016, 11:31:32 am
content: Schematics: K103v1-K backplane.The backplane includes the shared PFC for the system, as well as the secondary rail regulator.

author: technix
author_rank: Super Contributor
timestamp: May 06, 2016, 06:12:44 pm
content: K103v2-Q remote sense adapterFrom the very beginning I was deciding between the necessity of remote voltage sensing. This resulted in me designing this power supply using 4 uncommitted banana plugs on the front panel, allowing modules to define them when plugged in.This remote sense adapter is used to convert one set of unused banana plugs into the remote sense inputs for the channel above it (sending that sense signal into interconnect pins B8 and B9), and pull the pin B5 from interconnect interface hard high to notify the target module.This adapter is passive - just a bunch of wires. It have no circuitry.