For further particulars, consult the full electrical plan in Diagram of the galvanic arrangements.
Welcome, curious electrician and itinerant mechanician!
This repository contains the designs for a fully relay-driven controller
for a small standing carriage (hoverboard) executed in the idiom of the year 1884:
no semiconductors, much brass, a quantity of quicksilver, and a modest disregard
for personal safety.
Modern folk may call it a BLDC hoverboard controller.
We prefer polyphase electro-magnetic standing carriage, governed by relays.
- Polyphase electro-magnetic motor
- ~48 V nominal galvanic pile
- 3-phase BLDC, 30 poles (15 pairs)
- Star-formed connexion of the windings
- Two manners of “sight” for rotor position
- Minute magnetic contact-springs (reed switches)
- The motor’s own Hall instruments, poetically described as thinking sand
- A three-pole, double-throw Selector of Indicating Apparatus
chooses between Reeds and Sand.
- Six-step commutation gear (Ahead & Astern)
- Implemented entirely with relays
- Provides advance and retrograde motion for the standing carriage.
- Inclination & Safety governance
- Four mercury keys per side:
- two for gentle inclination (current through a limiting resistor)
- two for deep inclination (bypassing said resistor for greater torque)
- pairs provided for both advance and retrograde lean.
- Foot Cut-out beneath each standing board:
a spring-tongued safety switch that opens the circuit the moment the rider’s foot departs.
- Four mercury keys per side:
- Synchronous DC–DC Converter
- Converts ~48 V from the pile to ~5 V for delicate contrivances
- Works by two double-contact relays cavorting with a small transformer.
In plainer speech:
-
A 48 V battery (voltaic pile) feeds:
- the motor power stage (three phases via relay switching),
- the converter that produces 5 V for logic and indicators.
-
Mercury tilt switches and Foot Cut-outs decide whether any power is to be granted at all, and at what level of enthusiasm.
-
The position sensors (either Hall elements or reed switches) inform the six-step relay commutator, which energises the phases in due order for forward or backward motion.
-
A series resistor is included for gentle starting; additional mercury keys short this resistor at greater lean, giving a “full-zeal” torque mode.
Strong Warning: this project concerns high currents, rotating machinery, sharp edges, and occasionally boiling electrolyte. It is, by design, not safe. You proceed entirely at your own risk.
- A 3-phase BLDC hub motor with Hall sensors
- A ~48 V battery of your favourite persuasion
- A collection of relays (DPDT / 3PDT as per schematics)
- Mercury tilt switches (or mechanical equivalents if you prefer fewer environmental sins)
- Reed switches & small magnets (for the “minute contact-springs”)
- Miscellaneous brass, wire, and courage.
-
Study the engravings in
hardware/
Begin with the motor drawing and commutation diagrams, then proceed to the Foot Cut-out and mercury keys. -
Construct the power stage
- Follow the six-step relay arrangement for the three motor phases.
- Provide fuses (fusible safety wires) rated sensibly for your currents.
-
Install inclination & Foot Cut-outs
- Mount four mercury keys per side as indicated.
- Fit the Foot Cut-out beneath each standing board.
-
Wire the selector of indicating apparatus
- Bring the three sensor lines either from the Hall elements
or from the reed switches, through the selector to the commutator.
- Bring the three sensor lines either from the Hall elements
-
Perform cautious trials
- Lift the wheels clear of the ground.
- Verify advance and retrograde motion at small battery voltage
before entrusting any part of your anatomy to the device.
If you wish to join the Order:
- Fork this repository.
- Commit your improvements, engravings, or errata.
- Open a Pull Request, briefly explaining:
- what you changed, and
- whether you tested it on a live standing carriage or merely in the theatre of your imagination.
Bug reports and tales of narrowly-avoided disaster are also gratefully received.
This work is released under the curious charter in LICENSE.md, which wraps:
- MIT License – for all software and textual incantations, and
- CERN Open Hardware Licence – for all hardware designs and layouts,
all presented as the “Licence of the Most Serene Order of Galvanic Monks (1884)”.
In legal disputes, the sober MIT/CERN-OHL texts prevail; in tavern disputes, the one with fewer burns and bruises is presumed to be in the right.
May your coils remain cool, your relays chatter cheerfully,
and your standing carriage bear you neither into the ditch
nor into the annals of coroners’ reports.
— skrubis, 1884 (and somewhat later)