Instruments For Testing Your Innovations
Waveform amplifier is a very handy piece of equipment to have in the lab. Most function generator, pulse generator, and arbitrary waveform generator output voltage are limited to about 10V. Function generator output resistance is typically 50 ohm, making it not suitable driving low resistance (high current) load. For applications require higher voltage or higher current or both, a waveform power amplifier is required. For applications require to drive heavy load, the waveform output resistance must be very low (e.g. less than 1 ohm). Similarly some applications require to drive high capacitance, a high power amplifier is needed. The TS200 and the TS250 are high voltage and high current amplifier for general laboratory and bench testing. It can output up to 65V (TS250-
Figure 1. TS200 waveform amplifier functional equivalent circuit.
Figure 2 shows how to amplify a function generator to drive heavy load or large capacitance. It uses the TS200 wideband power amplifier. The function generator or pulse generator output is connected the TS200 modulation input. The TS200 output is connected to the load. Typically, the TS200 DC Offset or DC output voltage is set to zero and input modulation is set to DC-
Figure 2. Application diagram showing a signal generator is amplified by TS200 for driving heavy load.
The TS200 modulation output can be AC-
In summary, a function generator produces the desired signal waveform and the TS200 amplifies the signal to drive high current load or high capacitive load. The TS200 amplifier is flexible enough to work with a variety of function generators, pulse generators, and arbitrary waveform generators.
Figure 1 shows the functional equivalent diagram of the TS200 lab amplifier. It features a selectable AC or DC coupled input. It also feature an adjustable DC offset voltage output which is useful for LDO PSRR and line transient response testing. Two versions of the TS200 are available, the A-
Most function generator and signal generator output voltage are limited to about +/-
Many research and development laboratory such as those in universities and other R&D facilities often required laboratory power amplifiers that can output high power, or high current, or high voltage, or any of the combination. Examples of laboratory amplifier usages are driving Helmholtz coil (high current), MEMS or microelectromechanical systems (high voltage), pulse and transient thermal generation (high power), driving piezo transducer (high voltage and high current), and much more. The TS200 and TS250 are ideal bench equipment for R&D lab amplifier.
Magnetic coils are use to produce magnetic field for applications such as scientific experiments, lab test and measurement, magnetic interference, calibration, and much more. To produce high-
Function Generator Amplifier Connection
Figure 3. The TS250 is acting as high current function generator to drive an Helmholtz coil pair.
Many bench tests and lab experiments uses common signal generator. These signal generation equipment are either weak in output current or low output voltage. Example of such signal is DAQ (data acquisition system). Most DAQ analog outputs can only drive about 10mA and up to about 10V. If the bench testing requires high current signal (i.e. 5A) for driving an AC magnetic coil, a signal generator amplifier is needed to “amplify” the current with or without amplifying the voltage as shown in Figure 4.
General laboratory power amplifier
Scientific and industrial testing
Driving magnetic coil
Optical switches and modulators
Automotive transient test
Copyright: Waveform Amplifier for Function Generator
Figure 5. Using two amplifier drivers connected together will increase the current by two fold.
As shown in the Selection Guide below, the TS200 and TS250 are capable of output very high current from 1.4A to 6A. For some laboratory experiments, even higher current or power is needed. Fortunately two or three lab amplifiers can be parallel connected as illustrated in Fig 5. The total current is the sum of the two waveform amplifiers current combined. The two high-
Figure 4. Example of signal generator amplifier producing alternating magnetic field.