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100 kHz DC-to-DC
A pulse-width modulator (PWM) controls all necessary switching to
transmit waveforms, including self-oscillation, current sensing for
duty cycle, and a square wave output, through the main isolation
transformer to the secondary side.
Switcher Feedback Power
Provides sufficient power to sustain proper operation of the DC-to-
DC converter.
Gate Drive Transformer
Conducts signals provided by the PWM to FETs for actual voltage
and current switching for the main isolation transformer.
Main Isolation Transformer
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Delivers power to the system via primary and secondary taps.
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Provides necessary isolation to meet safety requirements.
Secondary Side
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Battery chargers.
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Provides precision 12 VDC output to charge the battery;
provides 2.4 V and 0.25 V reference outputs via resistor dividers.
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Independent current sensor and amplifier for each battery
provides input to an op amp current-limiting amplifier.
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Current amplifier also provides input for 15 V and 13.5 V battery
voltage switching sensor.
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A common input derived from temperature sensor and
compared to 10 VDC reference provides 6.7 VDC reference
voltage at 25° C.
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Battery charge/discharge.
Battery Disconnect
Removes any type of load that would discharge a battery to below
approximately 10 VDC.