KTA-200 Dual Amplifier / Attenuator
Assembling the Kit
First solder in place all the resistors (leave out resistors R2 and R5 for voltage signals, solder them in for 4-20mA
signals) and terminals. Next solder in place all the capacitors noting the polarity of the electrolytic capacitors.
Solder in the diodes noting their polarity and finally solder in the 8 pin socket for the Operational Amplifier. Insert the
operational amplifier correctly into its socket.
If you want a gain of 0.1 to 0.667 solder the 50K potentiometer into P2 for op amp OP1 and P4 for op amp OP2
If you want a gain of 1.5 to 10 solder the 50K potentiometer into P1 for op amp OP1 and P3 for op amp OP2.
Before applying power put the jumper in position J1 for a unipolar power supply. Connect the positive side of the
supply to +Vs and the common of the supply to COM.
For a bipolar power supply put the jumper in position J2. Connect the positive side of the supply to +Vs, the
negative side of the supply to –Vs and the common to COM.
Calibrating the Amplifier for a Voltage Signal
Connect a 1 V voltage source to I1+ and I1- (I2+ and I2-). Turn on the power. Connect a multimeter to the output
O1+ and O1- (O2+ and O2-). For a gain of 1.5 to 10 adjust the potentiometer P1 (P3) to the desired gain. For
example for a gain of 5 adjust the potentiometer until the multimeter reads 5V.
For a gain of 0.1 to 0.667 adjust the potentiometer P2 (P4) to the desired gain. For example for a gain of 0.5 adjust
the potentiometer until the multimeter reads 0.5V.
Repeat the same for the second operational amplifier.
Calibrating the Amplifier for a 4-20mA Signal
Connect a voltage source to I1+ and I1- (I2+ and I2-). Monitor the current flowing into the +I1 with a multimeter and
adjust the voltage source to give a reading of 20mA. Connect a multimeter to the output O1+ and O1- (O2+ and
O2-). For a gain of 1.5 to 10 adjust the potentiometer P1 (P3) to the desired gain. For a gain of 0.1 to 0.667 adjust
the potentiometer P2 (P4) to the desired gain.
Repeat the same for the other operational amplifier.
Parts List:
1 8-pin DIP socket (U1)
1 Jumper
1 3 pin connector strip
1 3-way terminal blocks (T1, T3-T4)
4 2-way terminal block (T2)
Semiconductors:
1 LT1013 Dual Op Amp
2 1N4148 silicon diode (D2)
Resistors:
2 100 ohm resistors
2 24K resistors
2 51K resistors
2 50K 25 turn trimpots
Capacitors:
2 0.1uF monolythic (C1-C2)
2 10uF electrolytic (C3-C4)
28 Jul 2010
www.oceancontrols.com.au
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