AC DIFFERENTIAL AMPLIFIERS
 
Model MDA-1
Model MDA-2


Description:

The Model MDA- 1 was designed for relatively low impedance differential recordings using metal microelectrodes. It is primarily intended for muscle and nerve studies where low noise and very high common mode rejection are necessary. This amplifier has both low and high frequency seven position cut-off switches. The unique feature of the Model MDA-1 is the ability to pass externally derived stimulus pulses through the recording electrodes via two front panel banana jacks. A three position switch selects the three modes of operation which are record, stimulate and gate-on stimulus. The later mode allows the investigator to program in the stimulus via the Model MDA-1 internal reed switches and gate-pulse input connector. The Model MDA-1 will remain in the stimulus mode as long as the gate pulse remains high and will return to the recording mode when it goes low. The Model MDA-l has a gain of 10 to 1,000 with continuous resolution and low output impedance for driving several signal processing and analog recording devices. The Model MDA-l is of modular construction and slides easily into the Model RP-1 rack mount power supply module cage system.

The Model MDA-2 is identical to the MDA-2 but does not include the stimulus delivery system.



Specifications:
Input Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 megohms
Output Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 ohms
Output Dynamic Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 volts peak to peak
Input Coupling  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC
Input Time Constant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 sec
High Cut-Off Ranges (3 db) . . . . . . . . . . . . . . . . . . . . . . . . . 0.1,0.2,0.5, 1,2,5 and 10kHz                
Low Cut-Off Ranges (3 db) . . . . . . . . . . . . . . . . . . . . . . . . .  1, 2, 10, 50, 100, 200 and 500Hz
Common Mode Rejection . . . . . . . . . . . . . . . . . . . . . . . . . .  90 db @ 60 Hz 44, 80 db @ 1 kHz
Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 to 1,000 (X1-X1O continuous one turn)
Noise less than . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 uV p-p (wide band)
Stimulus Gate Pulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4 volts min. (5 msec pulse width min.)
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  +15 volts @ 120 ma
Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.8"w x 5.25"h x 7.25"d


Other BAK epuipment often used with MDA-l,2:
 
DDIS1  Dual Window Discriminator  PSI-1   Pulsed Sample/Hold Integrator
DIS-1 Window Discriminator  PF-1 Paynter Filter
AD-3,6  Analog Delay ABI-1   AC Bridge Integrator 
ISI-1    Interspike Interval Convertor  BPG-1,2 Biphasic Pulse Generator
RG-1    Raster Stepper BSI-l   Biphasic Stimulus Isolator


Other BAK electronic amulifiers suitable for different requirements:
 
High Impedance Differential (microelectrodes): MDA-3, MDA-4
Built In Electrode Impedance Testing:  A-1, A-1B
Batter Powered: A-1B
True DC Amplification: DCDA-1, A-2 Intracellular
Low-Cost Single Ended: MMRS-1S
Multi-Channel Probe: MMRS-1P (25 single ended hybrid F.E.T. 's)


Our other Amplifiers
Metal Microelectrode Preamplifier and Impedance Tester, AC Differential Amplifiers, AC Differential Amplifiers with Remote Probe, AC Differential Amplifier with remote Probe and Impediance Test, D.C. Differential Amplifier with remote Probe, Micropipette Electrode Intracellular Probe System, Custom Designed Miniature Multichannel Recording System, Specification And Design Work Sheet: Model MMRS-1


Contact us at: P.O. Box 1600, Germantown, MD 20875
Phone: (301)540-3700 or (800)894-6000
Fax: (301)601-9018
E-mail: bakinc@erols.com
BAK ELECTRONICS, INC.
Biomedical Instrumentation
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