Abstract: A method for braking an electric utility vehicle including a motor and an electromechanical brake. The method includes storing a value indicative of at least one of an amount of current, voltage, and power that is commanded to a motor of the electric utility vehicle to maintain the electric utility vehicle in a stopped state; engaging a parking brake function of an electromechanical brake after the storing; disabling the motor after the engaging; commanding the at least one of the current, voltage, and power to the motor at the stored value when an accelerator pedal is depressed; and disengaging the parking brake function after the commanding.

Abstract: A method for braking an electric utility vehicle including a motor and an electromechanical brake. The method includes storing a value indicative of at least one of an amount of current, voltage, and power that is commanded to a motor of the electric utility vehicle to maintain the electric utility vehicle in a stopped state; engaging a parking brake function of an electromechanical brake after the storing; disabling the motor after the engaging; commanding the at least one of the current, voltage, and power to the motor at the stored value when an accelerator pedal is depressed; and disengaging the parking brake function after the commanding.

Abstract: A method for braking an electric utility vehicle including a motor and an electromechanical brake. The method includes storing a value indicative of at least one of an amount of current, voltage, and power that is commanded to a motor of the electric utility vehicle to maintain the electric utility vehicle in a stopped state; engaging a parking brake function of an electromechanical brake after the storing; disabling the motor after the engaging; commanding the at least one of the current, voltage, and power to the motor at the stored value when an accelerator pedal is depressed; and disengaging the parking brake function after the commanding.

Abstract: A drive system is provided for a utility vehicle and includes an alternating-current (AC) motor for providing a drive torque. An AC motor controller receives a battery voltage signal, throttle pedal position signal, brake pedal position signal, key switch signal, forward/neutral/reverse (FNR) signal, and run/tow signal indicative of the utility vehicle being configured to be driven and being configured to be towed. The AC motor controller generates an AC drive signal for the AC motor, wherein the AC drive signal is based on the battery voltage signal, throttle pedal position signal, brake pedal position signal, key switch signal, FNR signal, and run/tow signal.

Abstract: A drive system is provided for a utility vehicle and includes an alternating-current (AC) motor for providing a drive torque. An AC motor controller receives a battery voltage signal, throttle pedal position signal, brake pedal position signal, key switch signal, forward/neutral/reverse (FNR) signal, and run/tow signal indicative of the utility vehicle being configured to be driven and being configured to be towed. The AC motor controller generates an AC drive signal for the AC motor, wherein the AC drive signal is based on the battery voltage signal, throttle pedal position signal, brake pedal position signal, key switch signal, FNR signal, and run/tow signal.

Abstract: A brake lighting system for a lightweight utility vehicle is provided. The brake lighting system can comprise a pressure sensitive brake light switch (PSBLS) operably connected to a brake pedal subassembly of the vehicle. The PSBLS is configured such that depression of a brake pedal included in the brake pedal subassembly compresses the pressure sensitive brake light switch. The brake lighting system additionally can comprise a brake light circuit that can comprise at least one brake light and an electronic switching device communicatively connected to the PSBLS. The electronic switching device is responsive to a brake light signal transmitted by the PSBLS when the PSBLS is compressed. Upon receipt of the brake light signal, the electronic switching device enables a current flow through the brake light to illuminate the brake light.

Abstract: A battery data-logging arrangement for use with an electric vehicle is disclosed. The arrangement includes a first analog-to-digital converter (A2D) that converts a battery voltage signal to battery voltage data. A second A2D converts a battery current signal to battery current data. A clock generates time data. A computer memory is associated with a central processing unit (CPU) that correlates and stores the battery voltage data, the battery current data, and the time data in the memory.

Abstract: A lightweight utility vehicle brake lighting system comprising a brake pedal position sensor, a controller and a brake light circuit. The brake pedal position sensor senses the position, e.g., amount of depression, of a vehicle brake pedal. The controller of interprets a brake pedal position signal from the brake pedal position sensor to determine the position of the brake pedal. When the controller determines that the brake pedal has been depressed to initiate a braking operation of the vehicle, the controller transmits a brake light signal to an electronic switching device, such as a relay switch, of the brake light circuit. Upon receipt of the brake light signal, the electronic switching closes to complete, or close, the brake light circuit to enable a current flow through the brake light circuit, thereby illuminating at least one brake light of the vehicle.

Abstract: A horn activation system for a lightweight utility vehicle can comprises a pressure sensitive horn switch (PSHS) operably connected to a horn button. The horn button is operable with the PSHS such that pressing the horn button compresses the PSHS. The horn activation system additionally can comprise an electronic switching device communicatively connected to the PSHS. The electronic switching device is responsive to a horn activation signal transmitted by the PSHS when the PSHS is compressed in response to depression of the horn button. The horn activation system further can comprise a horn configured to receive a current flow resulting from the electronic switching device closing a horn control circuit upon receipt of the horn activation signal.

Abstract: An EDM circuit that detects power transistor switch failure. A comparator 62 and a sample and hold stage 60 are used during a window of time formed by the off-time of a pulse generator to determine whether power switch MOSFET 30 is conducting. If MOSFET 30 is conducting during the off-time of the pulse generator LED 72 will emit light to indicate a failed power transistor switch.

Abstract: A closed loop servo feed system for an EDM ram. A gap voltage signal is processed to control the servo feed operation with respect to ram velocity and also ram direction. A first network is provided with a voltage to frequency section for controlling ram velocity. A second network includes a raise/lower ram section with a comparator to determine the direction of ram movement.

Abstract: A programmable system for controlling machining current magnitude and reducing it in a step function as gap voltage falls indicating gap short circuit condition. A set of off-time numbers are computed and stored in an off-time counter. These numbers are recomputed each time a new on or off time is entered in the pulse generator. The original off-time is the normal cutting parameter. As the gap voltage drops, indicating problems, the off-time starts doubling or increasing in a like manner until it has reached many times its normal duration.

Abstract: A programmable system for controlling maximum machining current. A current limit is entered into the system together with the on-time and off-time desired. The system operates to use the desired on-time and current values, but the off-time will be modified depending on the maximum current limit possible. This will protect the apparatus when an impossible combination has been entered by the operator. Minimum allowable period is calculated for any desired current limit. The desired period is subtracted from the minimum period and the difference added to the off-time if the result is positive.

Abstract: Included in the circuit are a pair of counter timer circuits, a pair of inverters and a D-type flip flop. The inputs of the counters are tied to a programmable computer buss. A number is loaded into the first counter representative of machining power pulse on-time and a second number is loaded into the second counter representative of machining power pulse off-time.As the first counter counts to 0, the pulse output from the first counter is passed through an inverter to the second counter to enable it. After the second counter counts to 0 there will be provided an output through the second inverter to initiate the operation of the first counter. The pulses which are produced at the termination of each count provide operation of a following flip-flop stage which is toggled to provide on-off time for the machining power pulses to the following power module of the electrical discharge machining apparatus.

Abstract: The servo circuit is operable to monitor gap conditions on any number of working leads up to four at the same time. It further has the capability of responding to high voltage operating conditions and then reducing the gap voltage being sensed to an appropriate level. An analog stage is then employed to pick out the most valuable information being provided from the several gap leads. An amplifier of the FET type is used to provide high input impedance to the circuit. An absolute value circuit is further included which in either polarity will rectify the gap signal back to the positive level.

Abstract: A programmable system for controlling maximum machining current. A current limit is entered into the system together with the on time and off time desired. The system operates to use the entered on-time and current values, but the off time will be modified depending on the maximum current limit possible. This will protect the apparatus when an impossible combination has been entered by the operator. The duty cycle is checked against a maximum level such as 87% or a like upper limit.

Abstract: Included in the power supply is an output module connected to the gap which module uses a power FET. This module has its current output and the current to the gap controlled as a linear function of the control voltage applied to the gate of the FET. A suitable input means for the control voltage, includes manually controlled potentiometers, microprocessors, keyboards and the like.

Abstract: A protection system circuit which senses and responds to abnormal gap voltage condition. The circuit is operable in either positive or negative polarity of the gap. The circuit includes two branches, one relating to positive gap polarity and the other to negative polarity. The appropriate one of the two branches is selected by enabling one of two comparators in the respective branches.

Abstract: The system includes a standard servo feed arrangement in which responsive to gap voltage, servo feed is controlled for the electrode tool or alternately the workpiece.A further part of the system includes a gap voltage sensing lead and an analog to digital converter. At a predetermined point, a programmable computer is activated to provide an output signal through a digital to analog converter to influence the servo feed being controlled by the standard type servo feed system.The output from the programmable computer is weighted with respect to the output amplifier to provide a predetermined ratio of magnitude of control. A further embodiment of our invention is a system similar to the servo system described above, but in which the additional control over the servo feed system is exercised responsive to power level sensed in the EDM gap.

Abstract: A digitally controlled and free-running multivibrator for the power supply is used to supply machining power pulses of predetermined ON and OFF time duration. The pulse output from the digital multivibrator is passed through at least one intermediate drive stage to trigger an electronic output switch, which is operatively connected both to a main DC power source and the gap, to actually provide the machining power pulses thereto. Responsive to a predetermined drop in gap voltage, a digitally predetermined extended OFF time is added.