Controlled Transistor Series Regulator A controlled transistor series regulaÂÂtor is shown in the figure. The circuit is quite similar to that of a simple transistor series voltage regulator except that an additional transistor Q2 is inserted in the circuit. The emitter terminal of this transistor Q2 is connected to the negative terminal of input supply […]
The efficiency of Zener regulated power supply becomes very low when the load current is high. Under such conditions a Zener controlled transistor is always used for maintaining output voltage constant. Basically there are two types of Zener controlled transistor voltage regulators. They are Series Voltage Regulators Shunt Voltage Regulators You may also go through
Basically there are two types of transistor voltage regulators. They are (i) Series Voltage Regulators and (ii) Shunt Voltage Regulators. Each type of circuit can provide an output dc voltage that is regulated or maintained at a predetermined value even if the input voltage varies or the load connected to the output terminal changes. You
A voltage regulator is designed to automatically ‘regulate’ voltage level. It basically steps down the input voltage to the desired level and keeps that in that same level during the supply. This makes sure that even when a load is applied the voltage doesn’t drop. Thus, a voltage regulator is used for two reasons:- To
INTRODUCTION Almost all basic household electronic circuits need an unregulated AC to be converted to constant DC, in order to operate the electronic device. All devices will have a certain power supply limit and the electronic circuits inside these devices must be able to supply a constant DC voltage within this limit. This DC supply
Description. This 8 function serial Christmas lamp controller is based on the IC UTC 8156 from Unisonic. Specially designed for the same purpose, the UTC 8156 can control the four lamps in 8 modes namely waves, sequential, slo-gol, chasing/flash, slow fade, twinkle/flash, steady ON and auto scan. Control signals for controlling the lamps will be
Description. This is the circuit diagram of a very powerful and efficient Ni-MH battery charger using IC LT4060 from Linear Technologies. In addition to Ni-MH batteries Ni-Cd batteries can be also charged by slightly modifying the circuit.For charging Ni-Cd batteries connect the CHEM pin (pin12) of the IC to +Vcc.Here the circuit is configured to
Description. This circuit diagram shows how to obtain a negative voltage from a positive voltage supply. Another advantage of this circuit is that, the negative voltage together with the original positive supply can be used to simulate a dual supply. The circuit is based on timer IC NE555. The NE555 is wired as an astable
Description. Here is the circuit diagram of a super bright LED night lamp that can be operated from the mains supply. Bridge D1 is used to rectify the AC mains voltage. The capacitor C1 and resistor R1 forms the current limiting circuit. 10 ultra bright white LEDs are wired in series to produce the required
Description. This circuit can be used to test whether mains voltage is present or not without having electric contact with mains line. The CMOS IC CD4033 is the heart of this circuit. The CD4033 consists of a 5 stage decade Johnson counter and an output decoder for converting the Johnson code to a 7 segment
Description. Here is the circuit diagram of a 5V transformer less power supply using minimum components. The working of this circuit is quite simple. Resistor R1 does the job of current limiting and bridge D1 rectifies the mains voltage. The Zener diode regulates the rectifier output to obtain a steady 5V DC and capacitor C2
Description. This could be the simplest FM transmitter circuit you can find on the internet. Only using a single transistor and few passive components, this transmitter can deliver signals up to 50 meters. The transistor Q1 serves as the modulator as well as oscillator. Capacitor C2 and inductor L1 forms the necessary tank circuit for
Description. Here is a simple circuit that can be used as a tachometer. The circuit is basically a frequency to current converter which converts the incoming signal into a proportional current to drive the meter. The deflection on the ammeter will be proportional to the frequency of the incoming signal. For using this circuit as
F to V Converter Circuit using LM555 Timer Description. Here is a very simple circuit diagram of a frequency to voltage (F to V) converter. Such a circuit finds numerous applications in projects like digital frequency meters, tachometers etc. The circuit is mainly based on a LM555 timer IC. The IC is wired in mono
Description. Here is the circuit diagram of a fully transistorized inverter that can drive up to 60W loads. Transistors Q1 and Q2 forms a 50Hz astable multivibrator. The output from the collector of Q2 is connected to the input of the Darlington pair formed by Q3 and Q4.Similarly the output of Q1 is coupled to
Description. This circuit diagram shows you how to make a 5V to 12V variable DC power supply from a fixed 5V regulator IC 7805. This is attained by adding two resistors R1 and R2 as shown in figure. When the resistors R1 and R2 are added the equation for the output voltage of 7805 becomesÂÂ
Description. This is the circuit diagram of a very sensitive electromagnetic field sensor which can sense electromagnetic field from 40Hz to 140Hz. The low noise opamp LF351 and associated components forms the pick-up section. 1uH coil L1 is used for sensing the field and the IC1 performs the necessary amplification. If the picked electromagnetic field
Description. Here is the circuit diagram of a simple and low cost AM radio. The working of this radio circuit is straight forward. Inductor L1 and capacitor C1 forms the necessary tank circuit. Diode D1 performs the job of de-modulation. Transistor T1 is wired as a preamplifier whose output is further amplified by the IC
Description. Here is the circuit diagram of a very versatile emergency lamp that can be operated in two modes (flasher and dimmer). The circuit is based on the dual op-amp IC LM358.The dimmer and flasher mode can be selected by using the switch S1. In the dimmer mode the output of IC1b will be pulses
Description. This is the circuit diagram of a very simple and cheap peak detector circuit. This circuit operates from 5V DC and can detect signals up to 150 KHz. Dual comparator IC LM393 is the heart of this circuit. First comparator IC1a is used for detecting the peak of the input signal. Second comparator IC1b
From the circuit named “looking into the drain” of the FET it is seen (for small signal operation) an equivalent circuit consisting of two generators in series, one of – u times the gate signal voltage Vin and the second (u + 1) times the source-signal voltage Vs and the resistance rd + ((a +
Description. Here is the circuit diagram of a 6W amplifier using the TA7222AP from Toshiba.TA7222AP is an excellent integrated audio amplifier which can deliver 5.8W to a 4 Ohms load at 12V supply voltage. The IC has very good features like, muting function, low distortion, high ripple rejection, short circuit protection, thermal shut down etc.
This article shows you how to test a relay. A relay will usually have a coil, pole terminal and a set of contacts. The set of contacts that are open when the relay is not energized are called normally open (N/O) contacts and the set of contacts that are closed when the relay is not
Description. This is the circuit diagram of a ding dong sound generator based on two NE555 timer ICs.The circuit is designed to toggle between two adjustable frequencies to produce the ding dong sound. The first NE555 (IC1) is wires as an astable multivibrator operating at 1Hz. The frequency of the second NE555 (IC2) is modulated
Description. Here is the circuit diagram of simple but highly effective TV remote jammer circuit. Most of the TV remotes have 38KHz operating frequency. A flood of IR beams in the same frequency can easily confuse the TV receiver and this is the operating principle of our jammer. The circuit is nothing but an astable
