Abstract: A battery charger for a lead acid battery having a power supply with an input connected to an AC signal and an output connected to the battery. The power supply provides a charge current to the battery. A clock connected to the AC signal provides clock pulses having transitions synchronized with zero crossings of the AC signal. A voltage monitor connected to the battery detects a battery voltage substantially simultaneously with a zero value of the charge current. A charge mode control is connected to the clock and the voltage monitor for commanding different battery charge currents. The voltage monitor includes a temperature compensation circuit. The battery charger includes a display module that can be placed at a location remote from the battery charger and convenient to the user.

Abstract: A power supply circuit detects ground fault paths, and miswiring of the load, using a test mode in which electrical power is applied to only one power output terminal of the power supply relative to the ground terminal, while substantially no electrical power is applied to the second power output terminal relative to the ground terminal. If application of power during the test mode causes substantial current flow through ground, then there is a ground fault path, or an incorrect connection between the midpoint of the load and ground. The power supply further includes unique features for signaling the presence and kind of fault it has detected; the power supply is capable of distinguishing between ground faults in at least two different locations, and when a fault is detected, the power supply signals the presence of the fault and its location, e.g., by timed blinking of the connected discharge light. These features are enhanced by a diagnostic analyzer for connection to the power supply.

Abstract: A power supply circuit detects ground fault paths, and miswiring of the load, using a test mode in which electrical power is applied to only one power output terminal of the power supply relative to the ground terminal, while substantially no electrical power is applied to the second power output terminal relative to the ground terminal. If application of power during the test mode causes substantial current flow through ground, then there is a ground fault path, or an incorrect connection between the midpoint of the load and ground. The power supply further includes unique features for signaling the presence and kind of fault it has detected; the power supply is capable of distinguishing between ground faults in at least two different locations, and when a fault is detected, the power supply signals the presence of the fault and its location, e.g., by timed blinking of the connected discharge light. These features are enhanced by a diagnostic analyzer for connection to the power supply.