PC-505B Manual, Rev. 201013
Warner
Instruments
A Harvard Apparatus Company
16
Grounds
–
Circuit and chassis ground connectors (black and green, respectively) are
binding posts supplied with a shorting link. For most recording situations, the
shorting link can remain connected with no detrimental effect in amplifier
performance. However, there are occasions where line noise can be reduced if the
two grounds are isolated from each other. We recommend that you test both
connected and unconnected configurations to determine which is best for your setup.
Headstage
The headstage, or probe, is a low leakage current, solid state, current-to-voltage
converter which is switch selectable between two feedback resistors.
The headstage input terminal is a 1 mm jack connector that accepts a 1 mm pin on the
electrode holder. Pin jacks on the side of the headstage provide for grounded and/or driven
shield applications.
The headstage housing is a metal enclosure which serves as a shield which is driven by
the command signal. The attached metal rod is used for mounting to a micromanipulator
and is insulated from the headstage housing. A 2.5 m cable with 8-pin DIN connector
attaches the headstage to the mating connector on the instrument rear panel.
NOTE:
Due to the requirement of maintaining the lowest possible instrument noise,
headstage input protection cannot be employed. As such,
strict handling precautions are
necessary to avoid damage to the headstage by static discharge
. (
See
page 18 for details.)
Headstage types, applications and features
Headstage Types
Application
Features
LC-201
Patch / Whole Cell
50 G
/500M
headstage.
Single channel currents up to ± 200 pA.
Whole cell currents up to ± 20 nA.
HC-202
Patch / Whole Cell
50 G
/50M
headstage.
Single channel currents up to ± 200 pA.
Whole cell currents up to ± 200 nA.
HB-205
Bilayer studies
50 G
headstage for bilayer.
Currents up to ± 200 pA.
Bilayer capacitance up to 250 pF.
Electrode holders
Electrode holders connect the glass micropipet electrode to the headstage. A fine
chlorided silver wire, the actual electrode, makes electrical contact between the headstage
input and the electrolyte solution in the micropipet.
