Article
Battery-Nearly-Empty Indicator
Simple but effective
This circuit gives a signal using an LED when the voltage of a monitored battery drops below an adjustable minimum value.
The NEI (Nearly-Empty-Indicator) consists of a voltage reference, a comparator and an LED indicator.
Materials
Extra info / Update
Note: Since the original publication of this project/article, some of the components, software elements, webpages and other elements might have been updated or changed.
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Bill of Materials
COMPONENT LIST
Resistors
R1 = 4.7kOhm
R2 = see text
R3,R4 = see text
R5 = 680kOhm
R6 = 22Ohm
R7 = 15kOhm
R8 = 27kOhm
P1 = 10kOhm trimpot
Capacitors
C1 = 2.2µF 16V
Semiconductors
D1 = LED, green
D2 = LED, red
D3 = LED, high-efficiency, red
T1 = 2N6028
IC1 = LM10
Miscellaneous
Prototyping board e.g. Elektor UPBB (Elex) Type 1
Resistors
R1 = 4.7kOhm
R2 = see text
R3,R4 = see text
R5 = 680kOhm
R6 = 22Ohm
R7 = 15kOhm
R8 = 27kOhm
P1 = 10kOhm trimpot
Capacitors
C1 = 2.2µF 16V
Semiconductors
D1 = LED, green
D2 = LED, red
D3 = LED, high-efficiency, red
T1 = 2N6028
IC1 = LM10
Miscellaneous
Prototyping board e.g. Elektor UPBB (Elex) Type 1
Discussion (2 comments)