Abstract: A directional locking caster convertible between a locked position and an unlocked position by application of a lateral force. Also disclosed are transport devices including the caster. Additionally, a transport device including a directional locking caster that is convertible from a locked position to an unlocked position via a cable release.

Abstract: A circuit for monitoring the DC content of an AC waveform includes a differential amplifier having one input connected to the AC waveform and the other input connected to a capacitive-coupled network that eliminates any DC component in the AC waveform at the frequency being monitored. Additional circuitry is required to cancel any phase shift and reactance of the coupling capacitor. The output of the differential amplifier is a signal which represents the amplitude and polarity of the DC content.

Abstract: A multi-phase undervoltage detection circuit is disclosed wherein a multi-phase input voltage is compared to a reference. If the peak level of the input voltage is above the reference, a capacitor is discharged. If the voltage of any one of the phases is below the reference, the capacitor charges above the level of the input to a flip-flop. At the same time the voltage of another of the phases clocks the flip-flop. Since the input of the flip-flop is "high" when it is clocked, it changes states and its output goes "low" which provides a circuit output indicative of an undervoltage condition. If no undervoltage condition exists, the flip-flop will not change states and the circuit output is indicative of a non-undervoltage condition.