Supply Voltage Inputs; Power Led; Probe Supply; Probe Signal Input - Projekt Elektronik FM 302 Operating Manual

6. Operation

6.5.2.1 Supply Voltage Inputs

With these inputs the AS-probe adapter is connected to the power supply.
The adapter can be supplied with a DC voltage between 9 V and 36 V.
Since the adapter internally uses a DC/DC converter the current
consumption depends on the supply voltage. The higher the supply voltage,
the lower the current which is drawn by the adapter.
The input is equipped with a inverse polarity protection diode. Furthermore
besides an overvoltage suppressor the input has a protection circuit which
shortens the input in case of permanent overvoltage to protect the circuit. In
this case the also integrated resettable fuse will trigger after a few moments.
The threshold of the protection circuit is ~39 V. To reset the triggered
protection circuit the adapter has to be disconnected from the power supply.

6.5.2.2 Power LED

This LED lights up if the adapter is correctly supplied with power. If the LED
does not light up even though the adapter is connected to power supply
maybe the overvoltage protection circuit has triggered.

6.5.2.3 Probe Supply

At these outputs the ±3 V necessary to supply the AS-active-probe is
available. The outputs deliver a maximum current of 20 mA.
The supply of the probe and the input of the probe signal use the same GND
connection

6.5.2.4 Probe Signal Input

At this input the measurement signal delivered from the probe is connected.
The maximal converted input voltage range is ±2 V with gain x5 and ±0.2 V
with x50.
The supply of the probe and the input of the probe signal use the same GND
connection

6.5.2.5 Measurement Signal Output

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