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

!!!Guide to schematics

Theory of operation described the flow (or intended flow) of the circuits, and some of the reasons for extra relays, etc.

Key to schematics contains the decoder for the schematics and some basic explanations.

Parts list all components used to complete the EV conversion

!!!Primary circuit

High voltage, high current circuit.

[img[images/primary-icon.jpg][http://www.stealthbus.net/pdf/primary-wiring-B.pdf]]

!!!Secondary circuit

Low voltage control and warning systems.

[img[images/secondary-icon.jpg][http://www.stealthbus.net/pdf/secondary-wiring-A.pdf]]

!!!Modification to bus wiring

Changes to the original wiring harness to reuse dash lamps and ignition key

[img[images/buswiring_mods_icon.jpg][images/buswiring_mods.jpg]]

|!Label|!Description|!Physical location|!Schematic location|!Details|

|MC|Main Contactor|Controller panel|Contacts on primary, Coil on secondary|Controls negative rail to controller/Motor|

|RC|Run Contactor|Controller panel|Contacts on primary, Coil on secondary|Controls positive rail to controller|

|KSI|Key Switch Interlock|Controller panel|Contacts on primary, Coil on secondary|Controls pack voltage to enable controller|

|RL|Run Latch|Under dashboard|Secondary|Latches key when turned to “Start”|

|IS|Inertia Switch|Under dashboard|Secondary|Basic kill switch in case of accident|

|RR|Run Relay|Controller panel|Secondary|Latch “Start” from the existing wiring harness for isolation|

|MT|Motor Thermal|Motor|Secondary|Signals by opening contacts that motor is overheating|

|~MTa|Motor Thermal (a)|Controller panel|Secondary|Connects motor overheat to “OIL” dashboard lamp, and replicate “lamp test”|

|~CDa|Charger Detect (a)|Charger detect module|Secondary|Detects and signals by grounding pin that external power is connected|

|~CDb|Charger Detect (b)|Controller panel|Secondary|Invert logic from ~CDa to drive ~CDc correctly|

|~CDc|Charger Detect (c)|Controller panel|Secondary|Connects ~CDb to “GEN” for charger on state, and replicate “lamp test”|

|CI|Charger Interlock|Controller panel|Secondary|Disables RE & KSI if charger connected|

|RE|Run Enable|Controller panel|Secondary|Provide 1A drive for RC coil, since TPS switch rated at 0.2A|

|TPS|Throttle Pedal Switch|Throttle box|Secondary|Provides safety disconnect when throttle released|

!!!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.