Three-level voltage indicator on LEDs scheme – the name is very frightening not experienced radio amateur, but nevertheless “the devil is not as bad as it is drawn”. You can learn how to quickly and easily assemble an elementary voltage indicator by reading our article.
LED indicator:
It should be noted that this is a very common type of indicator, which is present in perhaps every elementary device such as a cell phone charger or rechargeable batteries, etc.
Three-level LED voltage indicator:
For a beginner radio amateur will be a very useful and informative elementary circuit very simple and miniature voltage level indicator on resistors and LEDs Figure 1.
VD1, VD2, VD3 – Any LEDs (any color and rating)
R1, R2, R3, – Substrate resistors selected depending on the parameters of the LEDs used (about 2 Kohm).
The word “three-level” means that you can track three levels of voltage decrease or increase (charging or discharging). For example, take three LEDs green, yellow, red and turn them on so that they show the corresponding voltage levels at a measurement step of about 2V.
You choose the levels for each LED by adjusting resistors R1 for VD1, R2 for VD2, R3 for VD3.
It is not necessary to increase the number of LEDs, as this leads to an increase in current on the first of them, which is not always acceptable.
This circuit solution is recommended for applications where the use of a voltmeter is not justified.
