ESP32 Constant-Current Booster Design
Budget: $30 – $250 USD
I need a compact, battery-powered driver that can generate a clean biphasic square wave with these key figures in mind:
• Frequency: adjustable 100 – 120 Hz
• Current: adjustable 0 – 20 mA (stretch goal 25 mA) into 500 Ω – 3 kΩ loads
• Architecture: DC-DC boost converter feeding a stable constant-current stage
• Protections: current limiting and a gentle soft-start
• Control: ESP32 handles all timing, adjustment, and safety logic
The DC-DC boost converter, the constant-current output stage, and the ESP32 control interface are all critical and must be treated as an integrated system rather than separate blocks.
Deliverables I expect:
1. Complete schematic ready for peer review (Altium, KiCad, or Eagle—your choice).
2. PCB layout optimized for low noise and battery efficiency.
3. Fully-annotated BOM with realistic part numbers and availability notes (Mouser/Digi-Key).
4. Brief design note outlining your topology choice, stability strategy, and how you achieved the biphasic waveform.
If you have worked on similar therapeutic stimulators, LED drivers, or precision current sources, please mention it and outline the approach you would take here, especially how you would:
• Generate the ± waveform without wasting battery life
• Maintain constant current across the full load range
• Implement soft-start and over-current protection without adding bulky components
Simulation results (LTspice, PSpice, or equivalent) are appreciated but not mandatory at this stage.
I’m ready to move quickly once I see a clear technical path.
• Frequency: adjustable 100 – 120 Hz
• Current: adjustable 0 – 20 mA (stretch goal 25 mA) into 500 Ω – 3 kΩ loads
• Architecture: DC-DC boost converter feeding a stable constant-current stage
• Protections: current limiting and a gentle soft-start
• Control: ESP32 handles all timing, adjustment, and safety logic
The DC-DC boost converter, the constant-current output stage, and the ESP32 control interface are all critical and must be treated as an integrated system rather than separate blocks.
Deliverables I expect:
1. Complete schematic ready for peer review (Altium, KiCad, or Eagle—your choice).
2. PCB layout optimized for low noise and battery efficiency.
3. Fully-annotated BOM with realistic part numbers and availability notes (Mouser/Digi-Key).
4. Brief design note outlining your topology choice, stability strategy, and how you achieved the biphasic waveform.
If you have worked on similar therapeutic stimulators, LED drivers, or precision current sources, please mention it and outline the approach you would take here, especially how you would:
• Generate the ± waveform without wasting battery life
• Maintain constant current across the full load range
• Implement soft-start and over-current protection without adding bulky components
Simulation results (LTspice, PSpice, or equivalent) are appreciated but not mandatory at this stage.
I’m ready to move quickly once I see a clear technical path.