Brownlee Precision 410 User manual

Instruction Manual
Brownlee Precision Model 410
Four-Channel Instrumentation Amplifier

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Operating instructions
Brownlee Precision Model 410
Four-Channel Instrumentation Amplifier
Power:
The Model 410‟s power requirements are 120 VAC, 47-63 Hz
unless otherwise indicated on the back panel near the power
connector. Run an IEC line cord from a wall socket to the back
panel power connector. The 2 Amp, 5x 20 mm type fuse is located
in the back panel power connector.
Turn on the power using the front panel power switch. The “ON”
will illuminate and, after a pause, the LED alphanumeric displays
will spell the startup message. After another pause, the displays
will spell out the amplifier settings and the amplifier is ready for
operation.
Troubleshooting: If the “ON” indicator does not light up, check
the fuse and power connection. If the “ON” does light up, but the
alphanumeric displays do not spell the startup message or
amplifier settings, push the reset button on the front panel.
Signal Connections:
Each of the four channels is an independent voltage amplifier with
a non-inverting (A) input, an inverting (B) input and an output, all
with BNC connectors. The input and output voltage ranges are +/-
10 Volts. Each input has 1 Mresistance and each output is
capable of driving +/- 100 mA.

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Amplifier Settings:
There are 5 main parameters, which can be adjusted on each
amplifier channel: Gain, Lowpass Filter cutoff frequency, Output
Offset voltage, Input Selection, and Input Coupling. There is a
button corresponding to each one of these parameters. Pushing one
of these buttons puts that parameter‟s value on the 8-digit
alphanumeric display. The knob can be used to adjust that
parameter.
To completely configure a channel of the amplifier, all 5
parameters must be set using the buttons and the knob. The
parameters may be set in any order.
To set the gain, push the „Gain‟ button and then turn the knob until
the desired value is displayed. The gain ranges from 1 to 10,000.
Gains of 1000 to 10,000 are abbreviated 1 K to 10 K, etc.
To set the Lowpass filter‟s cutoff frequency, push the „Lowpass
Filter‟ button and turn the knob until the desired value is displayed.
The cutoff frequency ranges from 1 kHz to 25 kHz. There is also a
wideband setting, abbreviated “WB”.
To set the output offset voltage, push the „Output Offset‟ button
and turn the knob until the desired value is displayed. Output offset
is abbreviated “OS”. The offset voltage ranges from –10 Volts to
+ 10 Volts in 0.5 Volts steps.
Handy tips: pushing the Output Offset button twice will
immediately reset the output offset voltage to zero.

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To select which input is to be amplified, push the „Input Select‟
button and turn the knob until desired configuration is displayed.
“Gnd” ignores both input lines and internally ties the inputs to 0
Volts for equipment setup and testing. The “A” setting amplifies
the single-ended signal on the A input. The “-B” setting amplifies
and inverts the single-ended signal on the –B input. The “A-B”
setting amplifies the difference between the A and –B inputs.
To set the input coupling, push the „Input Coupling‟ button and
turn the knob until the desired value is displayed, AC or DC.
Handy tips: For Input Select and Input Coupling, instead of
turning the knob to change the setting, you may also simply hit the
parameter button repeatedly to scroll through the values. For
example, the first time you push Input Select, the present input
setting is written to the alphanumeric display without changing it.
Each additional push of the button, however, will advance the
amplifier through its four options: Gnd, A, -B, A-B. The same
holds for Input Coupling.
It is important to remember that pushing a parameter button once
does not change the amplifier settings; it simply changes the
alphanumeric display. Turning the knob is the way to change the
amplifier‟s internal settings.
The amplifier‟s output is not affected by which parameter happens
to be displayed. You may want to leave the most frequently
adjusted parameter on the display. The amplifier will retain all the
settings for each channel when power is turned off, even if the unit
is unplugged.

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Memories
Each channel has one memory, which can hold a complete
configuration. Pressing “STO” stores all the present parameter
values for that channel without affecting the amplifier output.
Later on, even if some or all of the parameters have been changed,
pressing “RCL” will reset that channel to all the previously stored
settings.
Internal Offset Voltage Trimming
The electronic components at each stage of the amplifier have
inherent offset voltages, which could appear as a shift of the “zero”
level of the output. The Brownlee Precision Model 410 has a self-
trimming feature, which compensates for these errors
automatically.
Every time the gain is changed, the amplifier goes through a quick
adjustment routine. This routine does put a brief artifact on the
output signal as shown on the following page: The artifact‟s
duration is approximately 4 mS.
This self-trimming routine is only performed on the channel whose
gain is being changed. The artifact will not appear on the other
three channels.

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0 V
Horiz: 10 mS/div
Vert: 1 Volts/div
Sine signal w/ 1 Volts offset
If you notice the zero level of the output has drifted (as maybe
seen in the first few minutes after the amplifier is turned on) you
can invoke the self-trimming feature by changing the gain, or by
just double-clicking the Gain button.
Maintenance
ALWAYS remove the line cord before opening the cover of the
amplifier!
Lithium Rechargeable Battery: Very unlikely this battery will lose
its charge. If the amplifier is no longer holding its settings when
power is turned off, or you find you must frequently push the reset
button to turn the amplifier on, then contact Brownlee Precision
Company for replacement instructions.
User changes gain at
this point

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blank!)

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Amplifier Specifications:
Gain Range 1 to 10,000
Gain Accuracy < 2% error
Input Impedance 1 M, 15 pF
Input Voltage Range +/- 10 Volts
Input Bias Current < 50 pA
Input Offset Voltage < 5 µV
Common Mode Rejection Ratio > 70 dB
Wideband Voltage Noise, ref. to input < 20 µVp-p
Wideband Voltage Noise, ref. to output < 15 mVp-p
Noise Spectrum. 1 kHz, ref. to input 10-nV/ √Hz
At low gains, the total output noise is approximately RTO noise. At high gains, the total output noise
is approximately Gain x RTO noise.
Lowpass filter characteristic 2 poles elliptic
High frequency roll-off - 12 dB/octave
Slew Rate (input and output) 10 V/µS
Output Voltage Range +/- 10 Volts
Output Current +/- 100 mA
Output Offset Control Range +/- 10 Volts
Cross-talk Rejections *
No load on transmitting channel 130 dB
100 load on transmitting channel 120 dB
* Low impedance signal or ground on receiving channel
These specifications are believed to be accurate as of 7/2012, but are subject to change without
notice.

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Warning: This instrument is not for use on human subjects.
Model number: 410
Serial number: _______________
Firmware version: V 3.0
Ship Date: _______________
Warranty: 12 months, parts and labor
Instruction manual: 410 Rev. G
For inquiries call:
1-650-209-6666 Phone
1-408-538-3101 Fax
[email protected]
www.brownleeprecision.com
Brownlee Precision Company
2318C Walsh Ave
Santa Clara, CA 95051 USA

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April 2014
Brownlee Precision Company
2318C Walsh Ave.
Santa Clara, CA 95051
USA
1-650-209-6666 Phone
1-408-538-3101 Fax
[email protected]
www.brownleeprecision.com