A chiropractic adjusting instrument comprising a housing; a thrust nose piece and an impact head to contact a body; a preload switch plunger; a dampening spring; a solenoid having a core; a preload spring; a recoil spring; an electronic pulse system operatively connected to a power source to provide alternating current for energizing the solenoid to impart impulse energy from the core to the thrust nose piece which is reproducible and independent of the power source; and a trigger system for triggering the electronic pulse system comprising an switch activated by the preload switch plunger. Preferably, the chiropractic adjusting instrument includes one or more of the following: an intelligent universal AC power converter; optimized force-time waveform; pulse mode operation; and a suite of electromechanical components designed to promote reproducible dynamic force impulses and safe operation.