PB8 Pedal Box - 3 Wire Curtis Clone PB8 pedal box.

Mostly used for Navitas AC conversion on older Club Car Series carts, resistor carts and Marathons.

Has 2 wire activation switch and 3 wire potentiometer for throttle voltage. 

What the Curtis PB8 is

The Curtis PB8 Pedal Box (Potbox) is an electromechanical throttle-input assembly used in golf carts and other low-speed electric vehicles.

The unit is an interface between the accelerator pedal and the vehicle's motor controller. When the driver presses the accelerator, the PB8 converts the mechanical movement of the pedal into an electrical throttle signal that the controller can understand. 

What it is used for

Its primary job is to provide the throttle command to the motor controller.

Driver presses accelerator → PB8 detects pedal position → PB8 generates throttle signal → motor controller interprets signal → controller increases/decreases motor power.

Without an appropriate throttle input device, the motor controller would not know how much acceleration the driver is requesting.

This makes the PB8 particularly relevant when converting an older golf cart from a conventional resistor-based drive system to a modern AC motor/controller system, such as a Navitas conversion.

How the PB8 works

The PB8 contains two important electrical functions:

1. A 3-wire potentiometer
2. A 2-wire activation/interlock switch

The three-wire potentiometer is the part that translates pedal movement into an electrical throttle signal. As the accelerator pedal moves, it rotates the potentiometer. The resulting change in electrical signal is read by the motor controller and corresponds to the driver's requested throttle position.

The original Curtis/HPEVS wiring documentation identifies the three potentiometer connections as:

• Pot high
• Wiper
• Pot low

The wiper provides the variable signal associated with pedal position.

The second function is the interlock/activation switch. This provides an additional safety/control signal to the vehicle's electrical system. The HPEVS PB8 wiring documentation shows the switch operating in conjunction with the accelerator pedal and a normally closed circuit.

So, mechanically, the pedal moves the PB8's lever; electrically, the PB8 turns that movement into a signal that the controller can use.

What it is combined with

The PB8 does not normally operate as a standalone component. It forms part of the vehicle's complete propulsion control system.

A typical setup would look something like:

Accelerator pedal
↓
PB8 pedal box / potentiometer
↓
Motor controller — e.g. Navitas AC controller
↓
AC electric motor
↓
Golf-cart drivetrain / wheels

The PB8 is therefore the driver-input component, while the motor controller is the device that actually manages the electrical power delivered to the motor.

For older Club Car conversions, the PB8 is particularly useful because it provides the type of throttle input required by the newer controller system while retaining a conventional pedal-operated interface. The product listing specifically identifies Navitas AC conversions on older Club Car Series carts, resistor carts and Marathon carts as its main applications.

Why it is important in a conversion

When converting an older golf cart, you are effectively replacing the original method of controlling motor power with a modern electronic control system.

The new controller needs a reliable throttle input. The PB8 provides that connection between the physical accelerator pedal and the electronic controller.

For example, a conversion could involve:

• Existing accelerator pedal/linkage
• PB8 pedal box
• Navitas AC motor controller
• AC motor
• Appropriate batteries/battery pack
• Associated wiring and safety/interlock circuitry

The exact controller, motor, wiring and pedal linkage need to be compatible with the particular vehicle and conversion kit.

Component / Function

It is easy to confuse a pedal box/potbox with a motor controller.

They perform very different functions:

• Due to Curtis discontinuing the PB8 and PB6 boxes we are having to supply these clone boxes.  There are no longer Curtis built boxes in the world.