Source code for qcodes.instrument_drivers.devices

from typing import Optional, Union

from qcodes.instrument import Instrument
from qcodes.parameters import Parameter

[docs]class VoltageDivider(Parameter): """ Resitive voltage divider To be used when you use a physical voltage divider to set or get a voltage. Initialize the voltage diveder by passing the parameter to be measured and the value of the division (which should be calibrated beforehand) >>> vd = VoltageDivider(dac.chan0, 10) The voltage divider acts a your original parameter, but will set the right value, and store the division_value in the metadata. Set the value you want to set your device at 10 V >>> vd(10) This will set the dac.cha0 at 10*10, but upon measuring the divider the value returned is the voltage at the sample. >>> vd() 10 To get the voltage that was actually set on the instrument: >>> vd.get_instrument_value() 100 Args: v1: Parameter physically attached to the divider as input division_value: the divsion value of the divider label: label of this parameter, by default uses v1 label but attaches _attenuated name: name of this parameter, by default uses v1 name but attaches _attenuated """ def __init__(self, v1: Parameter, division_value: Union[int, float], name: Optional[str] = None, label: Optional[str] = None, instrument: Union[None, Instrument] = None) -> None: self.v1 = v1 self.division_value = division_value if label: self.label = label else: self.label = f"{self.v1.label}_attenuated" if not name: name = f"{}_attenuated" if not instrument: instrument = getattr(self.v1, "_instrument", None) super().__init__( name=name, instrument=instrument, label=self.label, unit=self.v1.unit, metadata=self.v1.metadata) # extend metadata self._meta_attrs.extend(["division_value"])
[docs] def set_raw(self, value: Union[int, float]) -> None: instrument_value = value * self.division_value self.v1.set(instrument_value)
[docs] def get_raw(self) -> Union[int, float]: """ Returns: value at which was set at the sample """ value = self.v1.get() / self.division_value return value
[docs] def get_instrument_value(self) -> Union[int, float]: """ Returns: value at which the attached parameter is (i.e. does not account for the scaling) """ return self.v1.get()