Error Detection; Hv Fault Error; Hv Detection Fault Error; Hv Diode Fault Error - Toshiba Aplio SSA-770A Service Manual

No. 2D730-148E*O
(g) Error detection
The TI board includes detection circuits for the following errors
a. HV fault error
This error occurs if the voltage for the HVSW embedded in the transducer is not
correct.
b. HV detection fault error
This error occurs under the following conditions. If this error occurs, the crowbar
circuit operates and stops supplying f 100 V.
l
The f 100-V power for the HVSW embedded in the transducer is applied to a
connector where no transducer is connected.
l
The f 100-V power for the HVSW embedded in the transducer is applied to a
connector where a transducer that does not require a high voltage is
connected.
c. HV diode fault error
The diode is set on the echo channel in order to clamp the echo channel to
prevent application of the f 100 V.
This error occurs if the diode is broken and a current resulting from the high
voltage flows in the echo channel.
d. Relay fault error
This error occurs if a relay for switching the transducer has values that are
different from those of the relay control register.
e. Over-current fault error
This error occurs if an over-current occurs in the power (+ 5 V for Zconv)
supplied to the transducer.
(h) Transmission disable signal generation
The TI board transfers the transmission disable signal (TXDIS) to the TR boards
under the following conditions.
l
An HV fault error is detected (a in (g))
l
An HV detection fault error is detected (b in (g))
l
An HV diode fault error is detected (c in (g))
l
A relay fault error is detected (d in (g))
l
An over-current fault error is detected (e in (g))
l
The HVSW in the 1.5 D transducer is in transition
l
The transducer selection relay is in transition
l
The transducer ID of the selected transducer is changed
l
An empty transducer connector is selected
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