Wet electronic developments

Two prototype solid-state switching devices and a multiplexer system were designed, fabricated, and successfully tested to demonstrate the use of solid-state devices under hydrostatic pressure cycling to 13,500 psi. The two switching devices were designed to use 24-Vdc voltages in controlling the application of 120-Vdc supply voltages, with a steady-state current of 10 A and surge currents of 100 A, to 1000-W incandescent lamps. One device, using silicon-controlled rectifiers, requires less than 0.06A and has a leakage current of about
1\mu
A. The second device, using power transistors, requires less than 0.13 A and has a leakage current of about
4\mu
A. The multiplexer provides 32 channels for control or instrumentation, but requires only four pressure-vessel penetrations. Testing of the prototype devices has demonstrated the feasibility of adapting solid-state devices for use in deep-ocean environments.