low battery indicator

176

03:06:29

this is a low battery indicator that flashes a green light after the voltage drops around 20V. If anyone could give me tips for better results with the same functionality, please leave a comment. Thanks 

published 6 years ago

Molar

6 years ago

Elliott, I believe there are better ways of doing this, for example by using zener diodes. I don’t like the idea of having the voltage to the timer being varied to control the blinking Led. You also have no resistors on either led. Are you dead set on making this design work?

ElliottGillespie

6 years ago

Hi Molar, even tho I am sticking with this particular design, I do want to know different ways to make it work. I am open to any suggestions you are willing to give me. It will help me a lot to learn more about electronics.

fatcat2

6 years ago

I suggest you to use a one with an additional source.

Molar

6 years ago

Do u mean an additional power source, fatcat? If so, I agree. Elliott, what do the red and green led on the right side indicate?

fatcat2

6 years ago

Yup. And that will consume very less power.

ElliottGillespie

6 years ago

The green always stays on . The red indicates a low voltage. At around 9.5 volts, the red light is supposed to light up with the 555 green light. Even tho i like the idea of using a second power source, i don't know how it would be possible in this situation.

fatcat2

6 years ago

Use a PNP BJT, an op-amp, or a BJT long-tailed pair. My preference is the op-amp.

ElliottGillespie

6 years ago

That's a great idea! I incorporated it in my circuit. Thank you!

fatcat2

6 years ago

Use an opamp and a reference voltage. That would take a very less space. Use a zener.

Molar

6 years ago

Another way of doing this is to pull pin 4 low and then pull it high when your voltage drops below 20V.

fatcat2

6 years ago

Use a comparator - op-amp or a BJT differential amplifier - or a current controller using PNP BJTs.

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