LEGO Technic 8720 Motor Voltage Details

ryanf

ryanf

add the stitching vias and the density to be greater on the gnd net for this board.

flux

0:19

Thought for a moment

I’ll increase GND stitching by setting denser fill-stitching rules on the GND net, then verify the rule and check for via/copper DRC issues.

flux

1:28

Thought for 5 sec

1/3 Inspect GND stitching rule configuration

Thought for 3 sec

Read layout.

Thought for 3 sec

2/3 Apply denser GND fill stitching rules

Thought for 3 sec

Editing layout rules.

Thought for 3 sec

3/3 Verify GND stitching rules and DRC

Thought for 4 sec

Completed 5 design checks — found 10 issues.

Read layout.

Thought for 1 sec

Read layout.

Thought for 3 sec

3/3 tasks completed.

Thought for a moment

Done. I set the GND net fill stitching to a denser 2.0 mm × 2.0 mm grid with 1.0 mm × 1.0 mm offset, and the via/copper DRC checks I ran show no open errors or warnings.
ryanf

ryanf

what is a nother diode like this that we can use that is in stock at jlcpcb. same footprint.

flux

0:15

Thought for a moment

I’ll identify the diode currently used in the design and its footprint, then look for an in-stock JLCPCB/LCSC alternative with the same footprint and similar or better ratings.

flux

0:44

Thought for 5 sec

Thought for 3 sec

Read schematic.

Thought for 4 sec

Found 3 results for Find JLCPCB/LCSC in-stock SMD Schottky diode alternative to B220 flyback diode, same SMB footprint D_SMB / DO-214AA, 2A or higher average forward current, 20V or higher reverse voltage, suitable for motor flyback, JLCPCB basic or extended part in stock..

Thought for a moment

For the D1, the best JLCPCB/LCSC alternative I found is SS54B: 5 A, 40 V Schottky, LCSC C360458, JLCPCB Extended Part. It is electrically stronger than the current D1 at 5 A vs 2 A and 40 V vs 20 V.
Caution: the library describes SS54B as SMB/DO-214AA-class, but its package metadata is not a perfect text match to D_SMB, so I’d verify the footprint overlay before replacing D1.
Verify SS54B footprint
Find exact SMB
Replace with SS54B
Prefer basic part
Check TVS alternative

Finished working

Sign up to send

Refine this doc
Ask about this doc
Raspberry Pi LEGO 9V Motor Controller Specification
Requirements
  • Control a LEGO 9 V DC motor, element number 74569.
  • Motor supply: external 9 V input.
  • Control input: Raspberry Pi 3.3 V GPIO/PWM signal.
  • Motor current: typical =2 A and >=20 V is preferred.
  • This is unidirectional speed control only. Reversing direction would require an H-bridge.
  • Raspberry Pi ground must be tied to the motor supply ground for a valid gate-drive reference.

    Requirements

    Selected Architecture

    Design Notes

Documents

    Raspberry Pi LEGO 9V Motor Controller Specification

Assets

Assets are files uploaded to this project which can be used in various ways.

✅ Raspberry Pi LEGO 9V Motor Controller thumbnail
PWM-capable low-side MOSFET driver for controlling a 9 V LEGO motor from a Raspberry Pi 3.3 V GPIO signal, sized for up to 1.4 A stall/current peaks.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$1.12–$1.61

Digi-Key

$301.41–$301.43

HQonline

$0.50–$0.53

LCSC

$1.78–$1.88

Mouser

$187.84

TME

$2.10

Verical

$1.94–$3.13

Controls