Adjustable output 1. It has a lot of transistors, Zener diodes, resistors, and capacitors. We cannot learn all about it. But I think we can do it.
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The following circuit examples simply depict few of the very interesting useful power supply circuits using this IC. The circuit provides an adjustable output right from 1. R2 is used for varying the output voltage continuously. Simple 5 Amp Regulated Power Supply Circuit This circuit produces an output that may be equal to the input supply voltage but the current is well regulated and can never exceed the 5 Amp mark.
R1 is precisely selected so as to maintain a safe 5 amp maximum current limit that can be withdrawn from the circuit. R8 is used for the voltage adjustment operations. Digitally Adjustable Power Supply Circuit: In the above designs, the power supply utilized a pot for implementing the voltage adjustment procedure, the below given design incorporates discrete transistors which can be digitally triggered separately for obtaining the relevant voltage levels at the outputs.
The collector resistance values are chosen in an incremental order so that a correspondingly varying voltages can be selected and becomes available through the external triggers.
The circuit shows a very simple design where a phototransistor replaces the resistor which normally acts as the component for adjusting the output voltage. The light which needs to be controlled is powered by the output of the IC and its light is allowed to fall on this phototransistor. As the light increases the value of the photo-transistor decreases which in turn pulls the ADJ pin of the IC more toward the ground, forcing the output voltage to decrease which also decreases the light illumination, maintaining a constant glow on the lamp.
The value of the preset determines the maximum amount of current that becomes permissible through the IC at the output. The resistor Rs may be selected appropriately for determining the desired level of current for the connected battery. R2 can be adjusted for obtaining other voltages for charging other categories of batteris. The inclusion of C1 makes it sure that the output from the circuit rises gradually to the set maximum level ensuring the intended safety to the connected circuit.
Heater Controller Circuit IC LM can also be configured for controlling temperature of a certain parameter like a heater. If the heat from the source tends to increase above the predetermined threshold, the sensor lowers its resistance correspondingly, forcing the output voltage of LM to fall, subsequently decreasing the voltage to the heater element.
Adjusting Many LM modules via a Single Control The given circuit shows a simple configuration which can be used for controlling the outputs of many LM power supply modules simultaneously though a single pot.
In the above section we learned a few of the important application circuits using the IC LM, which were basically collected from the datasheet of the IC, if you have more clues regarding such LM based circuits, please let us know through the comments below. You may also like:.
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