Comparison between BJT and MOSFET

Comparison between BJT and MOSFET

By Engr. Aneel Kumar   October 13, 2022   No comments:

Sr#	Bi-Polar Junction Transistor (BJT)	Metal Oxide Field Effect Transistor (MOSFET)
1	It is a Bipolar Device	It is majority carrier Device
2	Current control Device	Voltage control Device.
3	Output is controlled by controlling base current	Output is controlled by controlling gate voltage
4	Negative temperature coefficient	Positive temperature coefficient
5	So, paralleling of BJT is difficult.	So, paralleling of this device is easy.
6	Dive circuit is complex. It should provide	Dive circuit is simple. It should provide
7	constant current (Base current)	constant voltage (gate voltage)
8	Losses are low.	Losses are higher than BJTs.
9	So used in high power applications.	Used in low power applications.
10	BJTs have high voltage and current ratings.	They have less voltage and current ratings.
11	Switching frequency is lower than MOSFET.	Switching frequency is high.

Read More

Safety Measures in Trial Pits and Trenches for Underground Cabling Works

Safety Measures in Trial Pits and Trenches for Underground Cabling Works

By Engr. Aneel Kumar   May 13, 2022   No comments:

When carrying out the work of cable laying in the underground transmission line, the trench is to be dug/ prepared. Trench work should be done by following safety precautions. All pits and trench work shall comply with WorkSafe requirements, particularly the WorkSafe Code of Practice: Excavation. They may include but are not limited to:

• When a pit is to be left open overnight, proper barrier mesh and flashing lights, etc as required or the pit must be covered.
• Soil must be piled safely back from the edge of the pit.
• Pits or trenches deeper than 1500mm in normal soil may require a ladder for access and require shoring, benching or sloping of the sides of them.
• Pits or trenches may require shoring if less than 1500mm deep and the soil is unstable.
• Undermining walls, foundations, streets or pavements are to be avoided otherwise appropriate shoring is required.
• All shoring, benching and sloping must be installed.
• Barriers shall be erected to vehicles inadvertently falling into the excavation. Local councils may have more onerous conditions that need to be met.
• Collapse or flooding of trenches.
• Lack of ventilation or suitable lighting.
• Dangerous gases.
• Confined working space.
• High temperatures.
• Traffic hazards

Read More