Skip to main content
Electrical Engineering

Return to Question

Became Hot Network Question
added 5 characters in body; edited title
Source Link
JRE
JRE
  • 73.6k
  • 10
  • 112
  • 195

Please suggest any Improvementsimprovements for this reverse polarity protection circuit

I'm using this circuit for Reverse Polarity Protectionreverse polarity protection. The

The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended.

Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening.

Is it just a bad batch of MOSFETs?

How to make it run less hot without a fan? A better MOSFET?

Here is the datasheet of the MOSFET: https://www.infineon.com/dgdl/irf4905pbfHere is the datasheet of the MOSFET.pdf?fileId=5546d462533600a4015355e329b1197e

Reverse Polarity Protection

Please suggest any Improvements for this reverse polarity protection circuit

I'm using this circuit for Reverse Polarity Protection. The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended.

Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening.

Is it just a bad batch of MOSFETs?

How to make it run less hot without a fan? A better MOSFET?

Here is the datasheet of the MOSFET: https://www.infineon.com/dgdl/irf4905pbf.pdf?fileId=5546d462533600a4015355e329b1197e

Reverse Polarity Protection

Please suggest any improvements for this reverse polarity protection circuit

I'm using this circuit for reverse polarity protection.

The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended.

Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening.

Is it just a bad batch of MOSFETs?

How to make it run less hot without a fan? A better MOSFET?

Here is the datasheet of the MOSFET.

Reverse Polarity Protection

added 131 characters in body
Source Link
WhiteShark
WhiteShark
  • 123
  • 6

I'm using this circuit for Reverse Polarity Protection. The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended. Some

Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening. Is

Is it just a bad batch of MOSFETs? How

How to make it run less hot without a fan? A better MOSFET?

Here is the datasheet of the MOSFET: https://www.infineon.com/dgdl/irf4905pbf.pdf?fileId=5546d462533600a4015355e329b1197e

Reverse Polarity Protection

I'm using this circuit for Reverse Polarity Protection. The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended. Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening. Is it just a bad batch of MOSFETs? How to make it run less hot without a fan? A better MOSFET?

Reverse Polarity Protection

I'm using this circuit for Reverse Polarity Protection. The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended.

Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening.

Is it just a bad batch of MOSFETs?

How to make it run less hot without a fan? A better MOSFET?

Here is the datasheet of the MOSFET: https://www.infineon.com/dgdl/irf4905pbf.pdf?fileId=5546d462533600a4015355e329b1197e

Reverse Polarity Protection

Source Link
WhiteShark
WhiteShark
  • 123
  • 6

Please suggest any Improvements for this reverse polarity protection circuit

I'm using this circuit for Reverse Polarity Protection. The load draws 20A (11 DC motors) continuously for 2 hours after which the battery gets replaced. Even with a heat sink, the MOSFET gets extremely hot. Whenever there is a battery swap, I intentionally connect the battery in reverse to see if the behavior is as intended. Some of these MOSFETs have been running for days while others started conducting in reverse just 10 minutes into testing and I'm absolutely clueless as to why this is happening. Is it just a bad batch of MOSFETs? How to make it run less hot without a fan? A better MOSFET?

Reverse Polarity Protection