Theory of Operation 4
Overall Functional Description
∙11A DC Function:
The 11A dc function is implemented with a transconductance (voltage in/current out) amplifier with a gain of
∙11A AC Function
The 11A ac function is similar to the 11A dc function. The frequency range is 40 Hz to 10 kHz. The output range is 1 to 11A rms. As in the dc current function, all outputs from the 5725A either go through the front or rear panel of the 5725A. Input to the 5725A comes from the 5700A Oscillator assembly.
1100V AC Range Functional Description |
The 5700A Oscillator assembly generates the driving ac voltage, then sends it to the 5725A Power Amplifier for amplification. The 5725A returns an attenuated feedback voltage for output correction. The final output voltage is kept accurate by the high voltage sense amplifier and a
Active assemblies in the 5725A ac voltage function are as follows:
∙In the 5700A: CPU, DAC, Oscillator, Oscillator Control,
∙In the 5725A: CPU, High Voltage Amplifier, High Voltage Sense, Signal Transformer, Power Supply, Digital, and Interconnect assemblies.
When an ac voltage in the 220 to 1100V range is selected, the 5700A calls the 5725A amplifier and leaves its own high voltage amplifier dormant. The 5725A takes over the 1100V ac range automatically. The 5725A produces ac voltage in the following sequence:
1.The 5700A sets the Oscillator assembly to the proper frequency and amplitude. The 5700A sets the initial amplitude using an
2.Next, the 5725A Power Amplifier amplifies this signal by
3.The 5700A thermal sensor and adc