A drive circuit for an electromagnetic flowmeter, which drives an excitation coil for generating a magnetic field, the drive circuit comprising: a primary power supplier configured to supply a primary electric power to a primary winding of a transformer; a secondary power supplier (400, D413, C414) configured to supply an operation electric power and an excitation electric power, the operation electric power being output in accordance with a secondary electric power supplied to a secondary winding of the transformer _in accordance with the primary electric power supplied to the primary winding; a voltage value of the excitation electric power being different from a voltage value of the operation electric power; an excitation current supplier (406, 410, 411) to which the excitation electric power is supplied, the excitation current supplier (406, 410, 411) being configured to supply an excitation current to the excitation coil; a power supply monitor configured to compare the voltage value of the operation electric power with a predetermined voltage threshold, the power supply monitor being configured to output monitoring information representing whether or not the voltage value of the operation electric power is lower than the voltage threshold; and a controller configured to determine whether a short circuit has occurred in the excitation coil based on the monitoring information, the controller being configured to stop supplying the excitation current from the excitation current supplier (406, 410, 411) to the excitation coil if the controller determines that the short circuit has occurred in the excitation coil, wherein the voltage threshold is higher than a lowest voltage value with which the controller operates, and the voltage threshold is a voltage value representing that the short circuit has occurred in the excitation coil; wherein the controller is configured to count a first number of times the monitoring information changes from a state representing that the voltage value of the operation electric power is higher than or equal to the voltage threshold to a state representing that the voltage value of the operation electric power is lower than the voltage threshold, and wherein the controller continues to stop supplying the excitation current from the excitation current supplier (406, 410, 411) to the excitation coil if the first number of times is more than or equal to a predetermined second number of times. a primary power supplier configured to supply a primary electric power to a primary winding of a transformer; a secondary power supplier (400, D413, C414) configured to supply an operation electric power and an excitation electric power, the operation electric power being output in accordance with a secondary electric power supplied to a secondary winding of the transformer _in accordance with the primary electric power supplied to the primary winding; a voltage value of the excitation electric power being different from a voltage value of the operation electric power; an excitation current supplier (406, 410, 411) to which the excitation electric power is supplied, the excitation current supplier (406, 410, 411) being configured to supply an excitation current to the excitation coil; a power supply monitor configured to compare the voltage value of the operation electric power with a predetermined voltage threshold, the power supply monitor being configured to output monitoring information representing whether or not the voltage value of the operation electric power is lower than the voltage threshold; and a controller configured to determine whether a short circuit has occurred in the excitation coil based on the monitoring information, the controller being configured to stop supplying the excitation current from the excitation current supplier (406, 410, 411) to the excitation coil if the controller determines that the short circuit has occurred in the excitation coil, wherein the voltage threshold is higher than a lowest voltage value with which the controller operates, and the voltage threshold is a voltage value representing that the short circuit has occurred in the excitation coil; wherein the controller is configured to count a first number of times the monitoring information changes from a state representing that the voltage value of the operation electric power is higher than or equal to the voltage threshold to a state representing that the voltage value of the operation electric power is lower than the voltage threshold, and wherein the controller continues to stop supplying the excitation current from the excitation current supplier (406, 410, 411) to the excitation coil if the first number of times is more than or equal to a predetermined second number of times.