hi i am working on high frequency preamplifier for a strian gauge bridge.i have seen so many of articles but i am not understandig how to auto balance the starin gauge bridge(wheatstone bridge) .can you please explain me how can i autobalance the starin gauge wheatstone bridge without using potentiometer. and aslo can you pls provide me some sites related to this topic "high frequency preamplifier for strain gauge bridge by auto balancing method"