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how does a voltage stabilizer work Bipolar Junction Circuit (BJT) Ideas

by:KEBO      2019-10-26

Transistors are my favorite and most commonly used electrical components.I can only complete a few projects that don't need to use one of the devices.
The most common types of transistors are bipolar junction transistors (BJT) and field-effect transistors (FET ).
BJT consists of a thin layer of n-type or p-The type of semiconductor sandwiched between two layers of the opposite type of semiconductor.
This is a cross section of some basic applications of BJT transistors.Here I use them to choose educational and interesting projects.For novices, building one or two of them is a great way to improve electronic knowledge.
Image source: Wikipedia.
Each transistor in the design will increase the magnification by a factor equivalent to the transistor current gain;So the three in this chart can easily produce magnification close to 200x200 = 8,000,000.In order for the amplifier to reach saturation, the base only needs a very weak signal.
If you add a short copper wire antenna of about 3 inch to the bottom of the amplifier above;It can be used to detect the presence of mains AC current.To detect the presence of current, it does not need to be in direct contact with the main cable.The LED will flash and the buzzer will hum to indicate the presence.
This circuit will tell you when the soil in the pot dries.The soil/water mixture basically forms a basic resistance, and the collector current decreases as the resistance increases as the water dries.When the soil driesThe collector current drops to the voltage drop at both ends of the LED is not enough to light up the point of the LED.
This circuit makes it possible to activate a 12 volt relay with a smaller voltage, such as a 6 volt power supply.The idea used in the circuit is to apply an initial pulse of 12 volts to pull the pole and then hold the pole with 6 volts.Ideally, a relay with a rated voltage of 12 V will pull-Input at 12 V, but can be maintained with only 6 V.
Before the transistor is turned on, the storage capacitor is charged via a diode D1 through a 1 kohm resistor.When the two transistors are applied to the signal on the T1 base, the voltage on the capacitor increases the voltage of the 6 v supply, so the voltage applied to the relay is very close to 12 v.The capacitor will gradually discharge, but then the relay will pull successfully-In and will be able to maintain only 6 V.
The device can be used to provide constant current even under different load conditions.Voltage reference device;In this case, Zener diodes and resistors (R1) are used as voltage regulators.The regulator is used to drive the transmitter follower (T1), which is loaded by a constant transmitter resistor (R2) that senses the load current.The transistor (T1) will continuously adjust the current at the collector to make the voltage drop at both ends of the resistor (R2) close to the voltage drop at both ends of the Zener diode, which basically maintains a constant state.Regardless of whether the load changes or not, this will eventually keep the current provided to the load unchanged.
K = 1.


The device senses the presence of light and triggers an alarm.The circuit is the basic free circuit.An output operating oscillator used to drive a transistor amplifier.The resistance (LDR) that depends on the light is an optical induction assembly.Without the presence of light, the LDR has a high resistance.The oscillator does not oscillate until the light falls on the LDR.When the device is exposed to light, the resistance of the LDR drops sharply, and you can hum here.
If you want to use SRC but can't find any SRC;You can improvise with a BJT transistor.The picture above is the basic arrangement.

The OFF button takes away the voltage applied to the T2 base transistor, thus turning OFF the SCR.The off button can also be adjusted on both transistors, and the circuit will also be turned off as one of the current shunt.The On button is used to turn make-shift SCR.
The circuit will easily produce square oscillation in a wide frequency range, depending on the value of the capacitor (C1, C2) and the resistor (R2, R3.It is also possible to change the duty cycle of the oscillation by adjusting the values of these components.The output of this circuit can be used to drive other circuits and components.It is very easy technology to use it to produce oscillation.

Image source: Wikipedia.
Hartley oscillator belongs to the category of LC oscillator for generating a wide range of sine wave frequencies.They are characterized by an LC slot circuit on the collection side of the amplifier, and the inductance in the slot circuit is center tapped.



Image source: Wikipedia.

This is another LC-based sine wave oscillator that is widely used.It is similar to the Hartley oscillator, but the difference is that it has a tap in the middleThe point on the capacitor side of the tank circuit.

Image source: Wikipedia.
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