Mechatronics, Industrial Control & Instrumentation

How Signal Processing Circuits are protected from high currents & voltages

Protection against high currents and voltages is a very important requirement for signal processing circuits. A high current can be protected against by the incorporation in the input line of a series resistor to limit the amount of current flowing to an acceptable level and a fuse to break if the current exceeds a safe level. This arrangement is illustrated in the figure 1(a) below:

Protection against high currents using a series resistor & a fuse
Figure 1(a) protection against high currents using a series resistor & a fuse

It is also crucial that high currents or voltages are not transmitted from the sensor to a microprocessor hence it may be required to completely isolate the circuits so that there are no electrical connections between them. This can be accomplished by using an optoisolator as illustrated below:

Figure 1(b) optoisolator circuit

The optoisolator converts electrical signal into an optical signal (infrared radiation), transmits this optical signal to a detector which then converts it back into an electrical signal. The input signal passes through an infrared light-emitting diode (LED) which produces a beam of infrared radiation that is detected by a phototransistor.

Related: Optoelectronics

Share
John Mulindi

John Mulindi is an Industrial Instrumentation and Control Professional with a wide range of experience in electrical and electronics, process measurement, control systems and automation. In free time he spends time reading, taking adventure walks and watching football.

Recent Posts

What to Expect from PCB Assembly Services in China

The importance of printed circuit board (PCB) technology has escalated throughout the years with the…

2 days ago

Magneto-Optic Current Sensors for High Voltage, High Power Transmission Lines

One of the key challenges in measuring the electrical current in high voltage, high power…

4 days ago

How the Wiegand Effect is used in Sensing Instruments

The Concept behind Wiegand Effect Based Sensors   The Wiegand effect technology employs the unique…

6 days ago

Piezoelectric Accelerometer: Principle of Operation & Applications

An accelerometer is a sensor that is designed to measure acceleration or rate of change…

1 week ago

The USB-6009 Data Acquisition Card Features

The USB-6009 is a small external data acquisition and control device manufactured by National Instruments…

1 week ago

How X-Y Tables are used in Position Control Applications

X-Y tables are utilized as components in many systems where reprogrammable position control is desired.…

2 weeks ago