MOTORIZED VALVE BACKUP CIRCUIT

A control system for a motorized valve. The control system comprises a backup circuit comprising energy storage means and a discharge gate through which the energy storage means can be selectively discharged to provide a discharge actuation pulse to the valve to cause the valve to move to a safe (e.g. closed) position. The backup circuit further includes an energy harvesting circuit for harvesting power from the power supply lines. The energy harvesting circuit is able to harvest sufficient energy within the duration for a single actuation pulse provided by the motor controller to charge the energy storage means from zero to a sufficient level to allow the backup circuit to generate at least one corresponding discharge actuation pulse for causing the valve to move to the safe position.