Can the bridge rectifier be connected in this way to work in both positive and negative connections? Is the constant current resistance calculation reasonable?

QWE4562009

Can the bridge rectifier be connected in this way to work in both positive and negative connections? Is the constant current resistance calculation reasonable? [Copy link]

 

Can the bridge rectifier be connected in this way to work in both positive and negative connections? Is the constant current resistance calculation reasonable?

Jacktang

What do you want to do with the battery input and the entire bridge stack? Are you worried about connecting them in reverse? The design is a bit low-end.

Jacktang

The bridge stack is connected to direct current without distinguishing the positive or negative polarity of the power supply. Does this need to be confirmed?

The resistance range of the resistor to be measured should match the current provided by the constant current. Simply put, it is Ohm's law.

QWE4562009

Jacktang posted on 2024-10-13 08:50 What do you want to do with the battery input and the entire bridge stack? Are you worried about connecting it in reverse? The design is a bit low

I want it to work properly whether connected forward or reverse.

QWE4562009

Jacktang posted on 2024-10-13 08:50 What do you want to do with the battery input and the entire bridge stack? Are you worried about connecting it in reverse? The design is a bit low

Do you have a good method to post?

Gen_X

It is not economical just to prevent reverse flow, but the principle is feasible, and many instruments used to do so.

But as a driver, especially a low-voltage driver, it is generally not recommended to increase the "voltage drop" in the loop by at least 1.2V. For battery-powered devices, whether they work at constant current or not, there is a considerable (efficiency) loss. Take a look at the "ON" products on the world-famous power management chip, and you will find that many of its ideas are aimed at improving overall efficiency.

QWE4562009

Gen_X posted on 2024-10-15 09:13 It is not economical just to prevent reverse. But the principle is feasible. Many instruments did this in the past. But as a drive, especially a low-voltage drive, it is generally...

It doesn't mean to prevent reverse connection, but it needs to work with both forward and reverse connection.

qwqwqw2088

QWE4562009 posted on 2024-10-15 17:16 It does not mean to prevent reverse connection, but it needs to work in both forward and reverse connection

It’s okay to just consider being able to work.

This kind of anti-reverse is equivalent to connecting two diodes in series, and the voltage drop reaches more than 1V. If it is used in a large current, the loss will be very high.

qwqwqw2088

When the input voltage is low, such as a 3V button battery powered system, the voltage drop of the rectifier bridge may cause insufficient load voltage, which is not suitable for low voltage

qwqwqw2088

In some low-cost, mass-produced small household appliances or toys, for example, it may be more economical and practical to use a diode to prevent reverse connection.

Gen_X

Gen_X posted on 2024-10-15 09:13 It is not economical just to prevent reverse. But the principle is feasible. Many instruments did this in the past. But as a drive, especially a low-voltage drive, it is generally...

The key point is that the loop voltage drop at the battery site directly affects efficiency!

If you don't care, it's very good design.

QWE4562009

qwqwqw2088 posted on 2024-10-15 17:40 It is OK if you only consider that it can work. This kind of anti-reverse is equivalent to connecting two diodes in series, and the voltage drop reaches more than 1V. If it is used in the case of high current...

I have said that the purpose is not to prevent reverse connection, but to make it work normally when connected in both directions.