Model BSI-2
Description:
The Model BSI-2 Biphasic Stimulus Isolator has been optimized for applications
requiring precise control of rectangular waveform stimuli. It is designed
for use with external timing circuits which are biphasic single channel
(e.g. BAK BPG-l ,2) or dual channel TTL (BAK DC-1 Digital Controller or
other monophasic pulse signal sources such as computers). The external
timing input(s) gates each of the two photically isolated, independently
battery powered, constant current sources. Because they have completely
independent isolators, range controls, and output circuits, the" A" and"
B" outputs can be used as independent monophasic stimuli which are completely
isolated from each other as well as from the
control input. Each output has an inversion switch and an extra binding
post to facilitate installation of coupling capacitors or current monitoring
resistors. The two sets of output binding posts are strategically placed
so that the addition of two jumpers (provided) converts the unit instantly
to biphasic or pulse pair operation.
The Model BSI-2 features high compliance, high isolation, and the same
conveniently portable plastic case as the BSI- 1. The main difference is
that its output circuitry has been optimized for gated on-off operation
rather than proportional input following. This mode of operation is inherently
very low noise and eliminates the danger of applying DC currents as a result
of low level offsets in the control signal between output pulses. It also
permits manual fine tuning of the output level from the unit itself which
can be placed near the preparation. If you need non-rectangular waveforms
(e.g. sinusoids, ramps or computer D/A driving), we recommend the BSI-
1, a linear biphasic stimulus isolator with a complete range of both constant
current and constant voltage output levels.
| Constant Current | 100 nA to 10 mA each channel with polarity inversion switch |
| Current Control Ranges | 1,10, l00 and 1000uA.per turn via 5 position rotary switches each channel |
| Output Controls | 10 turn potentiometer with indicating dial each channel |
| Output Linearity | 1 % all ranges |
| Compliance Voltage | 90 volts each channel, independent battery sources |
| Isolation | 1000 VDC (photically isolated), <30pF between any two jacks |
| Output Connections | 3-way banana binding posts, 3 each channel |
| Input Connections | Floating BNC jacks |
| Input Signal: A/B Biphasic | +/- 2.8 V mm., TTL compatible, protected to +/-15V |
| Input Signal: B Only | +/- 2.8 V mm., TTL compatible, protected to +/-15V |
| Power Supply | 2: 8.4v (replace with BAK BPL-1I, Duracell ~ DA146 or equivalent)
2: 90V batteries (replace with BAK BPH-2, Burgess #V60 or equivalent) |
| Battery Life | 100 hours minimum |
| Package | Bench mount with supporting handle |
| Size | 3.5"h x 26"w x 7.5"d (less handle) |
| Weight | 5 lbs. (shipped with batteries installed) |
BPG- 1,2 Biphasic Pulse Generators
DC-1 Digital Controller
MDA-1 ,4 Differential Amplifiers with Stimulus Gating
A-1 Single Ended Extracellular Microelectrode Amplifier
