Category | Controller

Controller

Written by chivey on July 5, 2026 Tags: Controller

I’m planning on a 144v pack voltage to use the Motor in the upper end of it range, giving us maximum power / acceleration potential, especially given the “brick” natural of the aerodynamic profile.

From similar on line projects I found the Curtis 1231C is a very popular choice and also some builders are using the Kelly Controller which seems to be a newer entry on the market

The Curtis controller is a basic controller and is a little more expensive than the Kelly.

Conversely the Kelly controller has many options and external connections and is a little cheaper.

I like the Curtis simple and easy to use, but the geek in me wants all the status ~LEDs and serial ports of the Kelly controller. At the end of the day the most important thing is reliability and safety. For safety I’m leaning to simple sounds better – less things to go wrong. I will spend some more time researching both models and make the call here.

!!!Journal entries

2009 01 11 – Started looking at Logisystems as Curtis replacement

2009 06 05 – Ordered controller

2009 07 08 – Controller arrived

!!!Controller panel layout

Schematics updated for Logisystem based on user manual and online research.

!!!Journal entries

2009 08 15 – Secondary wiring completed

Schematics

Written by chivey on  Tags: Controller

Revisions

RevisionNotesLink
V1.2Lead Pack, LogiSystems ControllerSchematics : V1.2
V2.1GBS Pack, Soliton Jr ControllerCurrent

V2.1 – Overall design

Similar to V1.2 – there two main panels:
– Controller panel, has Soliton, Contactors, DC-DC.
– BMS panel, has BMS and other low voltage monitoring

Revised schematics : 1/3 - Overview

Controller panel

Mounted on shelf where gas tank used to be

Revised schematics : 2/3 - Controller panel
LABELDESCRIPTIONNOTES
MCMain ContactorIsolates traction pack from all discharge circuits
IN1/DOKDischarge OK signalSignal from BMS enabling Controller
IN2RPM sensorSignal from shaft sensor mounted on motor
(mislabeled TPS above)
OUT1Temperature hotSignal to enable Water Pump (WP)
THROTThottle connector3 pin to position sensor under pedal
DCIDC-DC Isolator RelayPrevents parasitic draw from 12v battery
Note DC-DC L input is from switched side of MC not hot side as shown
RRRun RelayPowers all S12 systems. 12v when bus is “Started”.
Key has gone from ACC/RUN -> START -> ACC/RUN
RLRun Latch RelayLatches when ACC + START are both 12v
AVC2Charger interfaceGenerates Pilot and Prox signal for J1772 connector
ACCAccessory powerFrom Ignition switch
STARTStart powerFrom Ignition switch
OILOil lampSignal to “Oil” lamp on dashboard – indicates motor overheat
WPWater Pump RelayEnables liquid cooling for Soliton
MTMotor Thermal RelayTriggers if motor over temp closes, triggers “Oil” lamp
VIVacuum Initate RelayTrigger on low vacuum for servo brakes (being replaced with always on version)
VPVacuum Power RelayHigh load relay to power vacuum pump (being replaced with always on version)
12V12v BatteryConnects via breaker to +12v side of aux battery
AMPAmplifierConnect to amplifer

BMS panel

Inside charging area near sliding door (protected from elements)

Revised schematics 3/3 - Battery Management System (BMS) panel
LABELDESCRIPTIONNOTES
VMa/bVoltmeterMounted on dashboard
AMa/bAmmeterMounted on dashboard
CHa/bCharger controlConnects to CC (Charge Control) Relay with control AC power to Charger
SOCState of ChargeConnects to VW fuel guage on dashboard
DOKDischarge OKConnect to controller panel -> Soliton, enables drive
S12Switched 12v12v when bus is “Started”
GENGenerator lampUsed by BMS for any Fault condition with battery system

Theory of operation

Written by chivey on  Tags: Controller

!!!Primary Circuit

The primary (144v) needs to be fed via the protection systems (fuse, circuit breaker, disconnects) to the Controller from there on to the Motor and back to the pack.

In my current design, I have the Batteries split front and rear in cargo area of the bus for Weight distribution.

Positive going connection is made from the battery pack to the fuse and then a circuit breaker located behind the drivers seat. This travels back to the Controller panel, where it goes through the Run Contactor (RC). The RC coil input from from the secondary circuit. The circuit continues to the Shunt (1000A/50mA), this feeds the B+ input of the Controller and S1 on Motor. M- is connected via a disconnect to A1 of the Motor. The Controller needs full pack voltage for the KSI input to enable the controller, so a Bosch style relay labelled Key Switch Interlock (KSI), connects from the Shunt to the Controller input. The coil for the KSI is driven from the secondary circuit.

Negative connection from the battery pack, travels to the Controller panel, and via the Main Contactor (MC), connects to B- on the Controller.

So MC, RC and KSI must all be powered to enable current to the controller and motor to flow.

!!!Secondary circuit

!!!!Dashboard

Starting under the dashboard, the “Run” from the ignition switch is connected to the Run Latch (RL) relay as is the “Start” line from the ignition. This is connected such that when the ignition is turned from “Run” to “Start” the relay is engerised latching the 12v from the “Run” of the ignition onto the ignition “Start” line.

The “Start” line from the ignition is connected via the Interia Switch (IS) to the “Ready” lamp on the dashboard.

!!!!Dashboard to Engine bay connection

The “Ready” light side of the IS is connected to the existing “Start” wire that runs to the rear of the bus.

The “Run” cable is left as-is since it connects to reverse lights and other systems on the bus which we do not want to interfer with.

!!!!Engine bay (Controller panel)

In the rear of the bus the “Start” wire connects to the RR coil.

Aux battery voltage connects to terminal 12V on the Controller panel, this fused with a 20A master fuse, this switched via the Run Relay (RR) to the other sub systems.

The switched 12V (from the RR), feeds via secondary protection fuses other cooling systems: Motor fan, Controller bay fans and fans on actually on the Controller.

!!!!Charger interlock (behind fuel door)

A small module consisting of a old Nokia mobile phone charger (universal input voltage 100-240v) with 5.3v output, powers a small reed relay (6v coil). The relay shorts the CD line to ground when power is present at the fuel input.

!!!!Charger interlock (Controller panel / Dashboard)

CD drives relay coils ~CDb and CI, these are powered from the switched 12V so only energise if the bus is in “Ready” Mode. ~CDb (N.C.) contacts invert the signal to ~CDc so that ~CDc energised if there is no external power and therefore connect the “GEN” line to 12v, with dashboard light “GEN” is connected to the Run signal from the ignition. This means when switching from ignition “Off” to “Run” the “GEN” light has +12v one side and GND the other(since ~CDc is not energised) and the lamp is lit for “lamp test” mode. Turning the key from “Run” to “Start” latches the RR and then energises ~CDc which switches the GEN line to +12V so the GEN lamp goes out – unless of course external power is present.

!!!!Main contactor (Controller panel)

Unless CI is energised, the Main Contactor (MC) will energise when the bus is in “Ready” mode.

!!!!Run contactor & Key Switch Interlock (Controller panel)

The Throttle Pedal Switch (TPS) shorts to GND and provides a current path for RE and KSI. So only when in “Ready” mode with CI not energised can both RE and KSI be energised. The contacts for RE provide high current path to energise the RC (requires 1A to hold). The TPS is only rated at 0.16A for DC.

!!!!Motor overheat (Controller panel / Dashboard)

The thermal contacts on the Motor (MT) will normally GND to the coil of ~MTa unless the Motor exceeds 120oC. The coil of ~MTa is fed from the switched 12V so is only active when the bus is in “Ready” state. The “Oil” signal line is reused and ~MTa provides the lamp test behivour just as ~CDc does.

!!!Design notes

Considering adding brake interlock switch to interrupt run enable, when brake pedal is pushed, run contactor power is disabled. Will look into bus wiring schematics and see the best location to add this.