Solid State Relays - These designs were improvements i made on the Application Notes of Motorola Semiconductor (freescale) and Thomson CSF (stmicro) Thyristor Data. The parts are still available, now made by other firms. You can also find similar equivalents.
Digital Interface to Analog Circuits is an example of Mixed Signal Design. Generating Digital Control Signals from the Analog sections in instruments is also done by Mixed Signal Circuit.
A/D Convertors and D/A Convertors are like Mixed Signal Chips. A Digital Potentiometer that controls an analog signal amplitude with a digital byte or word, figures in Mixed Design Circuit.
Temperature Controller 48-96 - A 1/8 DIN Indicating Temperature Controller. This is a Analog Controller built around ICL7107. This is a 48-96 DIN Temperature Controller, it is mains operated, it is in a Industrial Plastic Housing. It is not meant for very harsh environments.
Control panels are a part of industrial automation. It contains many DIN standard instruments both in the front panel and inside back rails along with the wiring. They are called panel mounting and rail mounting. Cable management is a Science in these equipment.
Analog devices like transistors and diodes lead to opamps and analog computing. This takes more parts but with fast devices can be real time. Then came Logic and Digital Circuits, here also big systems will take too many parts. A very Old hp Logic Analyzer instrument, could be HP1607A, had more than five large PCBs, Toggle Switches and numerous 74Fxx TTL Chips. I tried to revive it, it could not be fully restored.
Embedded Microcontroller - delabs
Then came the solution the Microprocessor. Here the entire system goes into the firmware and a Hardware Tool Set in the Microprocessor made up of Logic and Math is sequentially used to perform the same operation that would require innumerable Gates in a plain hardware digital circuit. But as it performs the operations one after another, it takes time and is defined by the CPU Clock Speed.