This particular circuit can be utilized for switching an LED bar graph in the upwards pattern or downwards order by using a pair of press button switches. The theory might be applied for several other practical apps.
In numerous circuit purposes we require a electronically managed control system allowing an upward or downward control of a specific parameter, for example for managing heat, sound volume, PWM, motor speed etc.
The application might appear uncomplicated nevertheless utilizing it virtually may not be so simple, except if customized (difficult to acquire) ICs are involved.
In this article we’re going see the similar would possibly be achieved by making use of the IC LM3915 which can be quite generally accessible worldwide and it is realistically inexpensive.
Knowing the suggested up/down LED series controller circuit utilizing push button is quite simple, and could be performed simply by mentioning the above mentioned figure.
The image displays a LM3915 LED bar graph driver IC, put together in its typical style.
Ten LEDs is seen linked over the ten outputs in the ICs.
The LEDs are meant to light up one following the additional in the straight pattern through pin#1 to pin#10 of the IC, according to a rising potential across its pin#5, which means so long as the potential at pin#5 is zero, each of the LEDs could be deemed to get turned off, and since the potential at pin#5 is increased, the LEDs could be observed lighting up sequentially through pin#1 till pin#10.
Pin#10 LED shows once the potential at pin#5 gets to about 2.2V.
The sequencing from the LEDs may be within the dot mode (while pin#9 is open) or even within the bar mode (when pin#9 is actually linked to the positive supply).
In the above design because the pin#9 is not really utilized or will be unconnected, the sequencing in the LEDs happen to be in the dot mode, which means only one LED is actually lit any kind of time on the spot over the appropriate pinout from the IC.
Regarding applying the up or down sequence, SW#1 or SW#2 must be personally pressed.
Whenever SW#2 is pressed, the capacitor across pin#5 on the IC is permitted to release gradually, evoking the potential to decline progressively until eventually may be it reaches 0V.
According to this the LED series might be observed “running” in reverse” from pin#10 to pin#1.
On the other hand whenever SW#1 is pressed, the 10uF capacitor is actually permitted to obtain charged slowly which usually requests the IC outputs to exert the LED sequencing from pin#1 towards pin#10.
Therefore the two push buttons might be properly pressed and released for accomplishing any one preferred pinout of the IC to be in the active condition, based upon the charge level of the pin#5 capacitor.
The concept could be applied for numerous other comparable apps by just combining the control stage using the several pinouts of the IC in the needed pattern.