Features
All WPI stimulus isolators are designed to supply constant current because current threshold (not voltage) is the most quantitatively reproducible parameter for stimulation of nerve and muscle. Model A395 dispenses current reproducibly from its Output terminals; the amplitude being determined by the selected current RANGE and the input voltage. Current amplitude is “constant”, that is, load resistance independent, provided that the I x R (load) product does not exceed the available battery supply voltage. A visual indicator (the compliance LEDs) displays if I x R reaches this limit. When the unit is out of compliance, one of the two LEDs (labeled - and +) illuminate, depending in which direction the current is flowing.
Output current
Model A395 generates an output current of arbitrary (user-defined) wave shape; DC, AC, pulse, and combinations thereof. Battery operated, and photoelectrically-isolated from the input voltage drive, the instrument regenerates output currents which are linearly proportional to the analog voltage waveforms provided by your D/A converter or signal generator. The A395 is ideally suited for data acquisition and stimulator generators. It can be easily daisy-chained for mutiple channel requirements.
Current Delivery
A 10 V input produces the maximum output current for the current range selected, i.e., 100 µA, 1mA, or 10mA. Front panel controls allow DC current to be generated. Externally applied signals can be superimposed simultaneously (DC offset). Warning lamps indicate open circuit or excessive current conditions.
Digital Meter
Measures DC or average output current.
Overload Lamps
Indicate when output voltage has reached positive or negative compliance voltage limit.
Specifications
INPUT
OUTPUT
OUTPUT CURRENT, Imax |
3 ranges: 100μA, 1mA, and 10mA |
OUTPUT VOLTAGE RANGE |
±70V |
OUTPUT BANDWIDTH |
10 kHz (measured across 1KΩ load R) |
INPUT RESISTANCE |
>20MΩ |
INPUT VOLTAGE @ Imax |
±10V |
INPUT/OUTPUT LINEARITY ERROR |
<0.5% |
RISE, FALL TIME |
26μs @ 10KΩ |
POWER: Model A395D |
17 alkaline 9V batteries |
POWER: Model A395R |
17 rechargeable NiMH 9V batteries |
DIMENSIONS |
6.5 x 4 x 3.5 in. (16 x 10 x 9 cm) |
SHIPPING WEIGHT |
4 lb. (1.8 kg) |
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