Leon: Computer controlled power/current supply, multimeter

From DP

Leon: Computer controlled power/current supply, multimeter
Codename	Leon
Status	Design in progress
Development	development forum
ID #	{{{id}}}

Contents 1 Links 2 Goals 2.1 Parts 3 Concept drawings 3.1 Older designs 4 Power supply schematics 5 Constant load schematics 6 Design resources 6.1 App notes 7 Chip notes

Links

• Development thread

Goals

• Initial goals for power supply
• Initial goals for Potential Pirate

• 0-12V output
• 0-1.5A output
• Current sink/dummy load
• X channels ADC
• Computer controlled
• 12V+ DC supply

Parts

• MC34063EC from ST Microelectronics. Buck topology configuration. Package not yet chosen (DIP or SO-8 package).
• AD8293G80/160 from Analog Devices. Fixed gain of 80 or 160, factory calibrated. 1.88$ @ Digikey.
• DG508from Vishay. 8 analog inputs up to 44 V.
• PIC24H series microcontroller

Current measurement options considered

• LT1637
• ACS712 Low Current Sensor Breakout board
• AttoPilot Voltage and Current Sense Breakout (TI INA169 also INA139)

Concept drawings

Dia sketch program used for diagrams

Older designs

Power supply schematics

Constant load schematics

Design resources

• MC34063A design tool
• EEVblog dummy load
• DaveCAD current sink
• Tux graphics power supply

App notes

• AN216-DCDC Converter Controller Using a PICmicro Microcontroller: For voltage supply and current supply schematics
• AN701-Switch Mode Battery Eliminator Based on a PIC16C72A: For buck converter calculations
• AN1114-Switch Mode Power Supply (SMPS) Topologies (Part I): SMPS topologies
• AN1207-Switch Mode Power Supply (SMPS) Topologies (Part II): SMPS calculations, very detailed
• AN1152-Achieving Higher ADC Resolution Using Oversampling: For increasing the ADC resolution
• AN954-Transformerless Power Supplies Resistive and Capacitive: For connecting the mains voltage
• App note: Variable resistor and temperature-indexed lookup table (LUT) compensate for regulator output

Chip notes

ADCs by PIC family:

24FJ family has 10+ 10bit @ 500ksps

24H has 10+ 12bit @ 500ksps

30F 12bit @200ksps, 10bit@1000ksps (1Msps)

33F 12bit @ 500ksps, 10bit @ 1Msps (some with DAC, some with 1-2 16bit ADCs @ 100ksps)