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.
They are called SSR as there are made of semiconductors and have no moving parts to wear out. They do generate heat depending on load and switching. Thyristors are used in most as they are rugged, mosfets and IGBT may also be used for various applications.
In this section you will find SSR designs and PCB layouts which you can study. These were made and sold by me years ago. So the PCB layouts have gone thru some revisions and they worked quite well.
Many machines and equipment use some SSRs in their products which may need replacement. So the SSR is not only sold to OEMs but also to Service-Maintenance Market. These are also modified as Output Modules for digital outputs coming from embedded systems or Computers.
Electromagnetic Relays - NO - Normally Open
when the relay is not energized or activated, this terminal is open-circuit.
NC - Normally Closed
when the relay is not energized or activated, this terminal is closed circuit.
COM - The Common
Center Terminal in relays. This is the center terminal that closes circuit with NC-NO.
The terminals are potential free and floating and are insulated from the control signals or coil windings by many kilo volts. Many provide visible isolation. These terms apply to SSR or Big Contacters too.
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.
Just like rackmounts hold big instruments or computers, control panels small or big have to hold DIN Instruments, switches and annunciators to make it easy for the operator. The maintenance work also is simple from the backside. It can be kept near the machinery which it controls.
Some Control panels go into Control Rooms at a distance away or at a greater height from the shop floor. This way they can monitor and give instructions while managing a larger process like processing of chemicals and at the same time safeguarding the instrumentation and computers with controlled environments.
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. Suitable for Control Panels in Control Rooms. It has a
accuracy and linearity of 0.5%. It had options of on-off or time
proportional control
Temperature
is the most common process parameter, Pressure seems to be next. Flow,
Humidity, Strain, Torque, Level, RPM, Distance and many more follow.
When
a physical parameter let us say distance is measured, we first need a
sensor that converts it into electrical values, digital,
pulses(events/limit) or analog. The sensor used for length is a Linear
encoder and it creates the electrical information for the DRO to
Display.
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.
Analog Designs have to handle Linear Signals, Like 2.03 V and 35.3812 mA. Waveforms of all shapes from Straight Line DC Levels to the Jittery and Multi-Frequency Audio Waveforms.
350 MHz Mixed Signal Oscilloscope HMO3524 by HAMEG Instruments
Mixed Signal IC or ASIC are chips that are mainly Digital on the Core but have peripheral I/O within the chip to interface with the real world outside, over Analog Signals. Sensors and Actuators use signals in the analog language. The CPU with its Math Power, speaks Digital Words, its behavior thus can be patterned by a Software Program.
Electrical Engineering encompasses Everything in Electronics. Communications, Computers etc. are further specializations of Electronics. So it is best to Identify Electrical Circuits with Electrical Designs which excludes Active Devices. It can include Electronic Products in the form of wireable modules.
So House and Factory wiring, Appliances like Ovens, Toasters, Power Generation and management; all these are electrical. Motors, Generators, Connectors, Relays, Contacters and Circuit Breakers are Electrical Components.
See a diagram i made for a Sequential Process Control Unit, custom built for Vacuum Impregnation;
A Radio or Power Inverter is Electronic. When an Inverter or Electronic AC-DC Motor Drive is used in a Control panel or Power Supply system, that integration is shown as an Electrical Circuit. I feel Simple Consumer Electronic Circuits using Diodes, Transistors, SCR, Capacitors and Resistors can also be taken under electrical circuits; when they are used in Mains-Power or Household Appliances. Solar Energy related circuits also can be studied under Electrical Power Circuits.
In Electronics RF-Microwave and Communications is a specialization area, Computer Hardware, Software, Internet form another major domain. Networking and Wireless data communication overlaps both the above.
Power Electronics and Instrumentation are fundamental domains needed for many. Industrial Automation with Process Control Instrumentation is unique, but is supported by the fundamental domains. Many more finer areas like Robotics and Medical Electronics have a much sharper focus.
