A compact x-ray source can include a circuit (10) providing reliable voltage isolation between low and high voltage sides (21, 23) of the circuit while allowing AC power transfer between the low and high voltage sides of the circuit to an x-ray tube electron emitter (43). Capacitors (11, 12) can provide the isolation between the low and high voltage sides of the circuit. The x-ray source (110) can utilize capacitors of a high voltage generator (67) to provide the voltage isolation. A compact x-ray source (110) can comprise a single transformer core (101) to transfer alternating current from two alternating current sources (104a, 104b) to an electron emitter (43) and a high voltage generator (107). A compact x-ray source (120) can comprise a high voltage sensing resistor (R1) disposed on a cylinder (41) of an x-ray tube (40).