File:Undervoltage battery switch, TL431+PMOS.png
Jump to navigation
Jump to search
Size of this preview: 800 × 348 pixels. Other resolutions: 320 × 139 pixels | 640 × 278 pixels | 1,591 × 692 pixels.
Original file (1,591 × 692 pixels, file size: 66 KB, MIME type: image/png)
Captions
Captions
Add a one-line explanation of what this file represents
Summary[edit]
| Description |
English: The simplest battery undervoltage lockout (UVLO) circuit employs a PMOS power transistor as a switch and a TL431 as the voltage comparator. It is an RS-type latch with dual reset inputs (the analog comparator and the optional OFF button). Lowest (cutoff) battery voltage must exceed the voltage drop on the TL431 (2.5V) and the gate-source of the transistor (assume 4V min - PMOS threshold voltages are still quite high). That is, it will serve a 2S lithium pack (7.0V cutoff) but not a single lithium cell. Likewise, the reasonable upper limit for battery voltage is around 15V (4S lithium pack) due to gate-source maximum rating of the PMOS. Higher voltages are possible with additional votage dividers or zeners protecting the gate and the cathode of the TL431. R1 must be scaled to source 1..2 mA into the TL431 (e.g. 2.4 to 4.7 kOhm for a 2S lithium battery). R2 may be scaled to pass currents as low as 0.1 mA, although 0.25 mA is more reliable. Both switches must be non-latching type.
Русский: Простейшая схема защиты батареи от переразряда при снижении напряжении (UVLO) - RS-триггер на TL431 и PMOS-ключе. Работает при напряжении батареи от 7В (две литиевые банки последовательно) до 15В (четыре банки). Большие напряжения возможны при условии защитных делителей напряжении в цепях затвора и стока. Не работает с одной литиевой банкой. Величина резистора R1 должна обеспечивать ток катода TL431 порядка 1...2 мА (больше незачем, перерасход батареи) - т.е. для двух литиевых банок выбираем от R1 2.4K до 4.7К. Резистор (делитель) R2 выбирается исходя из тока не менее 0.1 мА, лучше - 0.25 мА. Обе кнопки - без фиксации. |
| Date | |
| Source | Own work |
| Author | Retired electrician |
|
This work is ineligible for copyright and therefore in the public domain because it consists entirely of information that is common property and contains no original authorship. |
Licensing[edit]
I, the copyright holder of this work, hereby publish it under the following license:
 
|
This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. |
| The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
|
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 13:51, 12 October 2021 | | 1,591 × 692 (66 KB) | Retired electrician (talk | contribs) | {{Information |Description={{en|The simplest battery undervoltage lockout (UVLO) circuit employs a PMOS power transistor as a switch and a TL431 as the voltage comparator. Lowest (cutoff) battery voltage must exceed the voltage drop on the TL431 (2.5V) and the gate-source of the transistor (assume 4V min - PMOS threshold voltages are still quite high). That is, it will serve a 2S lithium pack (7.0 - 8.5V) but not a single lithium cell. R1 must be scaled to source 1 mA into the TL431 (e.g. 4.7... |
You cannot overwrite this file.
File usage on Commons
The following 2 pages use this file:
.png){kind=link}
