Building Your Own Strain Gauge Amplifier
Industrologic sells two different types of versatile and modestly priced strain gauge amplifier printed circuit boards.
Building your own versus purchasing Industrologic productsFor some applications, and for some individuals, purchasing a small quantity of Industrologic amplifiers may not be practical especially those who need to have products shipped outside the US, where shipping charges and tariffs may be more than the cost of the products. It may therefore be preferable for one of our customers or potential customers to build their own amplifier circuit, especially if only one amplifier is needed.
The schematic diagrams for both the SGAMP-2 and the SGAU are included in their respective Reference Manuals available on Industrologic's web site, and we consider it perfectly acceptable to use this information to prototype your own circuit for research and other non-commercial uses.
Of course we would be delighted to sell you a quantity of SGAMP-2 or SGAU boards, so once you have completed your research using your prototype, please contact us if one of our boards can provide a long term solution for your application. We can also provide custom and semi-custom strain gauge amplifiers if needed.
Information for building your ownIndustrologic strain gauge amplifiers are based on the Analog Devices AMP04 precision low power instrumentation amplifier. Although the AMP04 has impressive specifications and may be desired or required for many applications, there are other instrumentation amplifiers available from Analog Devices and other companies with the same pinout and the same functions as the AMP04 but with more modest specifications and pricing, for example, the Analog Devices AD623. Alternate chips may also be more available in some parts of the world.
Both the SGAMP-2 and the SGAU circuit boards include a 5 volt regulator to provide the excitation voltage to the strain gauges, and both include a filter capacitor to provide an approximately 1000HZ low pass filter. Beyond that, they are very much like the circuits described in the datasheets for the amplifier chips.