Precision Trading 60 R3.0 - Manual (Page 6)

Operator Manual, Supercharger 60 R3.0
Page 6 of 62
The TIMER provides all the required timing functions related to the charge and discharge
durations. Digital time and speed selectors provide the external inputs, while the four digit
readout of the CLOCK provides the elapsed time display.
The CURRENT CONTROL interprets the programmed current values and controls the angle of
firing of two SCR's to maintain a constant current in accordance to the feedback received from
a precision shunt.
Display of current is provided by an independent Digital Ammeter that uses the same shunt
used by the CURRENT CONTROL circuit.
Inputs from the TIMER, the SYSTEM MONITOR and the CONTROL SWITCH, determine
the operating mode of the CURRENT CONTROL circuit.
The SYSTEM MONITOR provides several safeguarding functions. It compares the measured
current against the programmed value and if they differ by more than one ampere, operation is
halted and a current malfunction is indicated.
It measures the battery voltage and compares it with the programmed number of cells. From
there, it determines during charge if the total voltage exceeds the equivalent of 1.75 V per cell,
indicating an Overvoltage condition, or during discharge if the total voltage is below the
equivalent of 1 volt per cell, indicating the end of the discharge cycle.
It checks for polarity reversal at voltages as low as .25V, as well as an absolute Overvoltage at
85 volts, both generating a voltage malfunction indication that prevents any further operation of
the unit.
It measures the temperature of the discharge heat dissipators and signals an overheat
malfunction if the internal temperature exceeds 90
o
C, as it could be caused by a fan failure or
an installation with restricted air flow. It also monitors the temperature of the batteries being
charged (via the TEMP-PLATE) and terminates the charge, indicating battery Overtemp, in the
event of battery overheating that may lead to thermal runaway.
The POWER REGULATOR provides all regulated voltages and power amplification as
required by the various circuits.
The VOLTAGE CONTROL CIRCUIT provides the functions that regulate the charging current
in the Constant Voltage (float) mode and in the Peak Voltage mode, transfers from Main to
Topping charge on a voltage peak or ends charging on a voltage peak (new feature).
The DIGITAL VOLTMETER provides internal battery voltage readings with resolutions of
0.1V and 0.01V, while a selectable external position allows single cell measurements to a
resolution of 0.001V.
Additional protection is provided by a high speed current limiter for the discharge transistor
bank, a slow speed current limiter for the charge circuit and a magnetic circuit breaker capable
of tripping under fast high current overload conditions.