|
Output: |
Output between 2µA and 32mA. Control
is achieved by a variable range switch with four selections (10µA, 100µA,
1mA, 10mA) and a three-turn dial. Pulses from high impedance
stimulators (constant current units) can result in cells "charging-up"
between stimuli, leading to stimulus loss. This problem has been overcome in
the DS3, which has an Output Discharge (Clamp) Circuit that operates
for 20µs after each stimulus pulse. This will discharge cells with
capacitances as high as 1000pF. |
|
Pulse Duration: |
Range: 20µs to 2s. One dial allows
continuous adjustment from 2 to 20, while another is used to select the
range (from 10µs, 100µs, 1ms, 10ms, 100ms or external source). Internal
pulse duration values have ± 10% accuracy. |
|
Output Terminals: |
A pair of 2mm touch-proof sockets on
the front panel spaced at 0.75". |
|
Polarity Switch: |
Normal: Red output terminal
positive.
Reverse: Red output terminal
negative. |
|
Indicator: |
An LED operates for the duration of
each output pulse. |
|
Compliance: |
90V from 10 x 9V batteries. This
reduces to 87V at the top of each output range. Note that battery
voltage will drop from 9V to ~6V with "old" batteries. |
|
Single Shot: |
A single-shot push button is provided.
This operates at all times irrespective of trigger input. |
|
Trigger: |
A positive pulse of between 3V and 20V
is required to trigger the stimulator. The trigger input current
varies from 6mA to 62mA over the above voltage range. Trigger pulse duration
should not normally be less than 4µs. |
|
Trigger Isolation: |
Optical coupling is employed between
the trigger source and the stimulator circuitry. The capacity coupling
is less than 3pF. |
|
Batteries: |
11 x PP3, IEC-6R61 style batteries.
Current is only drawn when delivering a pulse. Note that battery test
sockets are built-in. |
|
Dimensions: |
Panel size: 7.5 in x 4.3 in (190mm x
110mm).
Depth: 3.1 in (80mm) over knobs. |
|
Weight: |
28.22 oz (800g) complete with
batteries. |
Constant current stimulator