Strobed Supply Improves Strain Gauge Bridge Efficiency



The following schematic diagram shows a  method to reduce power consumption without sacrificing the bridge signal output level of a strain gauge.  Many situation will be applicable for this strain gauge bridge signal conditioning circuit, where continuous output is not a must. In the long time frame, this circuit will in idle state  for almost all the time, with only intermittent quick active states  (on times). A very extreme example for this signal conditioning circuit is where remote weight or height level  of a storage tanks is sampled once per hour. The idle current is around 150 μA, with active state current typically 50 mA (which is occurs at few milliseconds periods).

 

[Circuit’s schematic diagram source: Linear Technology Application Note]