Based on a combination of an unbalance bridge and an active unbalance bridge, a parasitic oscillation energy produced by an analogue circuit with a deep megative feedback is used for judging. In the process of judgement an executive circuit is used for accumulating the "parasitic energy", so that the bridge is based on a "temporals" the bridge works intermittently in an unbalance type on the temporary base.According to the active unbalance bridge circuit, some practical,low-cost, direct-reading specific auto-balance bridges ad specific outo-control devices can be disigned. |