Do you want to work in a factory, or in a research institute, or in a company, or teach in a school?
Factories are also divided into different types, there are application-oriented, generally do not need to design electrical circuits (modification of equipment or technological innovation, imported equipment, except Guo localization), as long as the electrical circuitry of the equipment to make it clear, on the line; there are also manufacturing-type, specializing in the manufacture of automatic control equipment, which requires the design of the work, you need to produce drawings. As for work in the Institute, more inseparable from the work of drawing. I don't need to tell you the situation in school, you are still in school, better understand the current situation. Specifically to which industry need what drawings, it depends on the customer's requirements, but the basic principles and and basic circuits are the same.
To give you an example.
A certain application-oriented factory an imported equipment above the "NON CONTACT METER RELAY" is damaged, due to the lack of imported parts can be replaced, there is no corresponding can be replaced domestically, this time the engineers need to design a set of "NON CONTACT METER RELAY". CONTACT METER RELAY" to replace it. Its function is as follows:
The "NON CONTACT METER RELAY" has two adjusting knobs, and two relays, using 220V AC power supply. two adjusting knobs, one of which can be adjusted to adjust the minimum voltage of the set value, and the other can be adjusted to adjust the maximum point pressure of the set value. The "NON CONTACT METER RELAY" input signal is a voltage value with an input range of 0-10V DC. When the input voltage is lower than the set value of the minimum voltage, one of the internal relays will be energized; when the input voltage is higher than the set value of the maximum voltage, the other relay will be energized, but the two relays cannot be energized at the same time.
If interested, you can design a control unit according to the above requirements to meet the requirements of this factory.
Wish you success in your endeavors.