Looking for how to go about adding a low battery indicator to my circuit

Bordodynov

Joined May 20, 2015
3,177
I agree with you about the price of the package. But my circuit is better in terms of current consumption. Also by the frequency of blinking you can estimate the degree of battery discharge. The lower the flashing frequency, the more discharged the battery is. Unfortunately for your circuit it is not possible to accurately estimate the consumption current due to the limitations of the spice model.
 

crutschow

Joined Mar 14, 2008
34,280
Unfortunately for your circuit it is not possible to accurately estimate the consumption current due to the limitations of the spice model.
For what model?
The only thing I see that is not correctly modeled is the CD40106 and that takes a very small current.

So there's a tradeoff between cost and current consumption.
 

Bordodynov

Joined May 20, 2015
3,177
In my circuit, the current consumption with a pulsing green LED is about 30 µA. The oscillator on the CD40106 element has a very delayed pulse front. Through the transistors at the input of the chip a noticeable current will flow. Here is the current for the HEF40106 chip (not found for the CD40106). It may be small for your circuit, but for mine it is noticeable even if the current consumption is tens of microamperes, it will make a noticeable contribution to the total current consumption.
2020-12-15_09-00-35.png

When I talked about the inaccuracy of the model, I meant exactly the failure to account for this current.
 
Top