Converter apparatus

Converter apparatus, comprising:

• a source of alternating potential,
• a load circuit,
• converter means having controlled rectifier devices connected, and gateable in a predetermined sequence, to interchange electrical energy between said source of alternating potential and said load circuit,
• gate drive means including pulse means for storing and subsequently releasing electrical energy to provide a gate drive pulse for each controlled rectifier device,
• and control means for said pulse means, said control means providing signals which initiate the storage of electrical energy by the pulse means for each controlled rectifier device, normally a predetermined number of electrical degrees immediately prior to the time the controlled rectifier device is to be gated, and which subsequently triggers a release of the stored energy precisely when the controlled rectifier device is to be gated,
• said predetermined number of electrical degrees being selected such that the electrical energy is stored for only one currently non-conductive device at any instant,
• said control means further concurrently storing energy for the last of the presently conductive controlled rectifier devices to be gated, such that electrical energy is stored, at any instant, for a maximum of two controlled rectifier devices.

Converter apparatus, comprising:

• a source of alternating potential,
• a load circuit,
• converter means having controlled rectifier devices connected, and gateable in a predetermined sequence, to interchange electrical energy between said source of alternating potential and said load circuit,
• gate drive means including pulse means for storing and subsequently releasing electrical energy to provide a gate drive pulse for each controlled rectifier device,
• and control means for said pulse means, said control means providing signals which initiate the storage of electrical energy by the pulse means for each controlled rectifier device, normally a predetermined number of electrical degrees immediately prior to the time the controlled rectifier device is to be gated, and which subsequently triggers a release of the stored energy precisely when the controlled rectifier device is to be gated,
• said control means providing a serial train of spaced logic signals, the leading edges of which coincide with the gating of a controlled rectifier device, and a group of logic signals, each of which corresponds to the conduction pattern of a different controlled rectifier device,
• said control means logically combining the logic signal from the group associated with the last controlled rectifier device to be gated with a logic signal from the serial train to determine when to initiate the storage of electrical energy for the next controlled rectifier device to be gated.