MODES of OPERATION:
Re: Electrode Resistance Test; BR: Bride Mode (continuous); CC: Current Clamp mode; VC Voltage Clamp mode (discontinuous); Mode selector: rotary switch with four positions (SEC-05LX), or push buttons (SEC-10LX), LED indicators; remote selection by TTL inputs.
Standard headstage (SH) / Whole cell Headstages (SEC-HSP):
Operation voltage ±15 V; size: 100x40x25mm, headstage enclosure is connected to ground; electrode connector: gold plated SUBCLIC (SH); BNC connector (SEC-HSP), both with driven shield. Driven shield output:2.3 mm connector, range ±15 V, impedance 250 Ω, ground: 2.3 mm connector or headstage enclosure. Input resistance: >10E+13 Ω (internally trimmable). Current range (continuous mode): 150 nA into100 MΩ (SH); 15 nA into 100 MΩ (SEC-HSP), other calibrations are possible. CC control: Coarse control for input capacitance compensation. Holding bar (SH): diameter 8 mm, length 10 cm. Mounting plate (SEC-SHP headstage) 60x50 mm with four 6 mm holes.
Differential input headstage (SEC-HSD):
Electrode connectors: two SUBCLIC connectors with driven shield; Input resistance > 10E+13 Ω; CMR >90 db; other parameters same as SH headstage.
High voltage headstage (SEC 10H system):
Operating voltage range: ±150 V; size: 100x50x30 mm with heat sink 100x50x20, grounded enclosure; connectors same as SH headstage; CC control: trim potentiometer, 15 turns.
Electrode Parameter Controls:
Leakage current: adjustable to zero with ten-turn control; offset: ten-turn control, ±400 mV; capacity compensation; range 0-30 pF; coarse control on headstage, adapts compensation circuit to electrode parameters; fine control: ten-turn potentiometer.
BANDWIDTH and SPEED OF RESPONSE:
Full power bandwidth (Re=0): >100 kHz; rise time (10-90%, Re = 100 MΩ)
ELECTRODE RESISTANCE TEST:
10 mV/MΩ, obtained by application of square current pulses ±1 nA, display XXX MΩ.
Overcompensation of capacity compensation, timer controlled, with remote switch connected via BNC connector (all systems). Application of DC pulses, variable frequency and amplitude, timer controlled, with remote switch connected via BNC connector (SEC-10 systems). Application of maximum continuous DC current, BUZZ, with toggle switch or remote switch connected via BNC connector (optional SEC-05 systems).
Turns off current injection and capacity compensation, function indicated by red/green LED, disabled / off / reset switch, threshold set with linear control (0- 1200 mV).
SWITCHED MODES PARAMETERS:
Switching frequency: linear control, 1.5-50 kHz; display: XX.XX kHz. Duty cycles: 1/2, 1/4, 1/8, selected by toggle switch.
CURRENT RANGE vs. DUTY CYCLE:
1/8 - 15 nA; 1/4 - 30nA, 1/2 - 60 nA (standard 15V headstage)
1/8 - 1.5 nA; 1/4 - 3 nA, 1/2 - 6 nA (low noise headstage)
1/8 - 150 nA; 1/4 - 300 nA, 1/2 - 600 nA (high voltage headstage).
SWITCHED MODE OUTPUTS:
Electrode potential: max. ±15 V, output impedance 250 Ω.
Switching frequency: TTL (0.5 V), output impedance 250 Ω.
Sensitivity: 0.1...10 V/nA in 1-2-5 steps, with lowpass Bessel filter, output impedance 250 Ω; sensitivity monitor: 1...7 V, 1V/switch position, output impedance 250 Ω; current display: X.XX nA.
Sensitivity x10 mV, with lowpass Bessel filter, output impedance 250 Ω; potential display: XXX mV.
AUDIO MONITOR: Pitch correlated with potential signal.
SEC-05: two-pole (standard version) or four-pole lowpass bessel filters (SEC-05LX-BF) with 16 corner frequencies, 20 Hz - 20 kHz. Frequency monitor: -8..+7 V, 1 V/switch position, output impedance 250 Ω.
SEC-10: four-pole lowpass Bessel filters tunable in three ranges 0.3 - 20 kHz, output impedance 250 Ω.
Inputs: 1 nA/V, 0.1 nA/V with ON/OFF switches, input resistance >100 kΩ.
HOLD: X.XX nA ten-turn digital control with -/0/+ switch, max. 10 nA.
Gated input (SEC-10 systems only): X.XX nA with +/0/- switch, TTL input (HI >2.5 V, input resistance 10 kΩ).
BRIDGE balance: XXX MΩ with ten-turn digital control.
Noise (BRIDGE MODE): 400µV pp / pA pp with 100 MΩ resistance ad 10 kHz bandwidth (internal four-pole Bessel filters).
Inputs: :10 mV/:40 mV, input resistance >100 kΩ.
HOLD: XXX mV, ten-turn digital control with +/0/- switch, max. 1000 mV.
RISE TIME LIMIT: 0-2 ms.
GAIN: 100 nA/V - 10 µA/V ten-turn linear control.
Noise (filters set to 10 kHz, other settings see below).