Available as an assembled Module and as a DIY project.
This Module is currently available.
This module creates a train of triggers/gates whose frequency can be set manually or controlled by an external voltage. The duration of each trigger/gate can also be set manually or controlled by an external voltage
http://synthcube.com/cart/steiner-ingebretsen-en/synthasystem-vc-trigger-generator
These merchants probably sell this module. Huh?