1991 sure the introduction of the first Hall effect shunt driver for the bar-graph ammeters. The Hall effect shunt measured the magnetic field around a power cable, without any physical connection. The magnetic field direction and intensity vary with the current, thus can be converted to a voltage, and used to drive a display of amperage, charge or discharge. 1998 saw a modified unit, this had a new output circuit that allowed it to drive a analogue meter. The new circuit could drive either 2 ammeters, or 2 different ammeter ranges, and powered from 12 or 24 volt supplies.

What advantage is obtained from this system ?

• there is no resistance, thus no heat build up
• the shunt carries no current,
• it cannot be overloaded by say engine start stall currents.
• fits on battery terminal post, allowing net current readings
• shunt can pick up battery voltage,
• ammeter and voltmeter are driven  by a single 3 core cable
• one unit can drive 30 amp and 50 amp meter, running 12 or 24 volt supply.
• small package size

new DC shunt specification

new AC shunt specification

bilge pump running monitor pumps x  4,

remote alarm drive x 2

new range of DC shunts fit over the power cable, and drive digital, or analogue meters, or bar-graphs direct, and includes voltage sensing input, integral one piece unit.

new range of AC shunts fit over the power cable, and drive digital, or analogue meters, or bar-graphs direct, and includes voltage sensing input, integral one piece unit.

amp hour

monitor specification

display

specification