The Caputron Linear Current Isolator model 1106S is a voltage controlled current source which is optimized for stimulation of extracellular and electrically excitable tissues. The 1106S high input impedance prevents ground loops, and it can be used for high frequency stimulations up to 500 kHz. This linear isolator has a...
The Caputron Linear Current Isolator model 1106S is a voltage controlled current source which is optimized for stimulation of extracellular and electrically excitable tissues. The 1106S high input impedance prevents ground loops, and it can be used for high frequency stimulations up to 500 kHz. This linear isolator has a best-in-class DC accuracy of 0.005% and a high output voltage slew rate. "Input charge balanced stimulation" is a selectable new feature which compensates the DC offset of the function generator. The 1106S allows for quick and easy experimentation with its simple user interface and requires minimal maintenance due to an error detection system, internal calibration and advanced power management.
Caputron Linear Current Isolator
- The Caputron Linear Current Isolator is optimized for electrophysiological experiments and features:
- High DC and AC precision
- -3dB bandwidth of 500 KHz
- Capable of removing input offset for accurate charge balanced stimulation
- Capable of removing output offset voltage
- EMI Shielded for lower noise level
- Rechargeable batteries with increased lifespan and capacity
- Low maintenance and simple user interface
Input signal range is ±10 V with overvoltage protection. If the input exceeds this range, the indicator LED on the front panel lights up. If input overload happens, the signal will be clipped at ±10 V and an error displayed. While device is on, the input section is designed to show a very high impedance (10 GΩ || 10 pF) to prevent ground loop. A BNC connector carries the signal inside the device.
The output compliance voltage of device is ±90 V for both ranges. The output impedance of the device is 7 MΩ || 260 nF. The circuit is floating and the impedance between input and output is more than 1 GΩ.
The Caputron 1106S Isolator is equipped with two different feedback networks. They provide 1 mA/V and 100 µA/V of conversion ratio. The maximum load for driving at 10 V input, is 8 kΩ for 1 mA/V and 80 kΩ for 100 µA/V ranges.
- High current mode with conversion ratio of 1 mA/V
- Low current mode with conversion ratio of 100 µA/V
DC Offset Removal
Since the main application of the device is the stimulation of tissues, the output is applied to electrodes inside a solution. Connecting a current source to electrodes in saline cause DC voltage at electrodes and the tissue. “DC offset removal” monitors the output voltage and helps keep the DC offset at 0 V during stimulation. Toggled off when intentional DC or low frequency component is required.
Charge Balance Stimulation
In order to have charge balanced stimulation, device should sink the exact same amount of charge that is delivered to the target. Function generators or DACs which can be used to command the current source, have DC offset at the output. Even a small amount of offset at the input, will be accumulated after multiple cycles and cause electrode corrosion. If charge balanced stimulation is required, toggle the charge balanced switch from “Normal” state to “Chrg blncd”.
Battery and Charging
This isolator uses high capacity 6800 mAh Lithium-ion batteries. The life time of these batteries are around 1200 periods of charging and discharging with minimal maintenance. After the lifespan of the battery, the capacity of them fall and the device needs to be charged more often. In this case it is easy to open the device and replace them with new rechargable batteries.
- 4 level battery indicator
- 5V 2A DC Adapter used only when charging the device
DC Transfer Characteristics
DC transfer characteristics describe conversion of input voltage to output current and the precision of the conversion in steady state.
AC Transfer Characteristics
AC characteristics are related to the process of output following the input. The following plots show the output gain and the output phase shift with a 1 Vpp sinusoid as input signal.
Isolator Comparison Table
This device comparison table provides an overview of the specifications and features between the Caputron Linear Current Isolator, A-M Systems Model 2200 Analog Stimulus Isolator and World Precision Instruments A395RC Linear Stimulus Isolator. Below is a table containing detailed data of different parameters that can be useful for assessment of each product. All products were new, calibrated and tested under the same exact conditions.