Description. This is the circuit diagram of a two channel audio line driver using the high performance dual opamp IC TSH22 from ST Microelectronics. The 25 MHz bandwidth, low distortion and high output current of the IC makes it possible to drive medium impedance loads at a high level of modulation. Here both of the […]
Description. This is of course the simplest electronic code lock circuit one can make. The circuit uses one transistor, a relay and few passive components. The simplicity does not have any influence on the performance and this circuit works really fine. The circuit is nothing but a simple transistor switch with a relay at its
Description. Here is the circuit diagram of a passive DX bass circuit that can be used with almost all audio amplifiers. This circuit is designed by Mr. Emmanuel Chipula (emmanuel@windowshoppingmalawi.com) from Malawi and was sent to us for publication.We tested this circuit in our lab and the result was fine.Full credit of this circuit goes
Description. This lead acid battery charger circuit is designed in response to a request from Mr.Devdas .C. His requirement was a circuit to charge two 12V/7AH lead acid batteries in series.Anyway he did not mentioned the no of cells per each 12V battery. The no of cells/battery is also an important parameter and here I
Description. Here is the circuit diagram of a simple subwoofer filter that can be operated from a 12V DC supply. Such a circuit is very useful in automobile subwoofer applications. The circuit is nothing but a low pass filter whose pass frequency can be adjusted between 60 to 160 Hz. The circuit is designed around
Description. Here is the circuit diagram of a very simple wire loop alarm based on a N-channel enhancement FET 2N700, a buzzer and few passive components.In normal condition the gate of 2N700 (Q1) is connected to the ground through a 100K resistor (R2) and the wire loop. When the wire loop is broken , Q1
Description. The circuit diagram shown here is of a automatic changeover switch using IC LTC4412 from Linear Technologies. This circuit can be used for the automatic switchover of a load between a battery and a wall adapter.LTC4412 controls an external P-channel MOSFET to create a near ideal diode function for power switch over and load
Description. Here is the circuit diagram of a 12V boost converter using IC LM2698 from National Semiconductors. The LM2698 is a general purpose boost converter with an 18V, 1.35A. 0.2 Ohm internal switch. This results in high efficiency power conversion to outputs ranging from 2.2V to 17V DC. The input supply voltage range is 2.2V
Description. Here is the circuit diagram of a 5V buck switching regulator based on the IC LM2678 from National Semiconductors. LM2678 series of regulators are monolithic integrated circuits which provide all necessary functions required for a buck switching regulator and can drive up to 5A loads. The IC has more than 90% efficiency and has
Description. This is the circuit diagram of the simplest single chip AM radio. The circuit is designed around the IC ZN414Z which is a ten transistor tuned radio frequency receiver .The IC has only three leads and is available in the TO92 package. All necessary circuits required for an AM receiver (RF amplifier, detector and
Description. A very stable and simple FM transmitter circuit is given here. With a matching antenna, this transmitter can attain a range of around 200 meters. I assembled this transmitter few years and got very good results. Let us see how the circuit works. A condenser microphone (K1) is used to pick the sound to
Description. First of all let me remind you that this circuit is a very dangerous one. The output voltage of this circuit is in Kilo volts and it can seriously injure you or kill you. Try this circuit only if you have enough experience dealing with high voltages. I have no responsibility on any hazards
Making a frequency to voltage converter – All you need to know Description LM331 is basically a precision voltage to frequency converter from National Semiconductors. The IC has a hand full of applications like analog to digital conversion, long term integration, voltage to frequency conversion, frequency to voltage conversion. Wide dynamic range and excellent linearity
Description. The circuit given here can be used for tossing head or tail. There are many games in which a tossing is required to start and this circuit can be used in all such instances. The circuit uses two ICs NE 555 timer (IC1) and 74LS76 dual JK flip flop (IC2).The IC 1 is wired
Description. This is a simple circuit that can be used as a sequential signal light in automobiles. The circuit is based on two ICs. A TS 555 CN CMOS timer IC and a CD4017 decade counter IC. The IC1 is wired as an astable multivibrator to trigger the counter IC. When triggered, the outputs of
Description. This circuit was designed in response to a request from my reader. What he asked for was a 1KHz IR transmitter circuit for some remote control application. I think this circuit may satisfy him. Any way this circuit can be used where ever a low power IR transmitter of 1 KHz operating frequency is
Description. The dark detector circuit shown here can be used to produce an audible alarm when the light inside a room goes OFF. The circuit is build around timer IC NE555. A general purpose LDR is used for sensing the light. When proper light is falling on the LDR its resistance is very low. When
Description. When ever you need to get an alarm or intimation after ten minutes ,the circuit shown below can be used.The circuit is nothing but a monostable multivibrator based on IC NE 555.When ever you press the reset push button the green LED D1 glows after 10 minutes. Circuit diagram with Parts list. Notes. Assemble
Description. The main part of this doorbell circuit are two NE555 timer ICs.When some one presses switch S1 momentarily, the loud speaker sounds a bell tone as long as the time period of the monostable multivibrator built around IC1. When the switch S1 pressed, IC1 is triggered at its pin 2 and output pin 3
Description. An NE555 timer IC connected as shown here can detect a missing pulse or abnormally long period between two consecutive pulses in a train of pulses. Such circuits can be used to detect the intermittent firing of the spark plug of an automobile or to monitor the heart beat of a sick patient. The
Description. Apart from the timing functions ,the two comparators of the 555 timer can be used independently for other applications.One example is a Schmitt Trigger shown here. The two comparator inputs (pin 2 & 6) are tied together and biased at 1/2 Vcc through a voltage divider R1 and R2.Since the threshold comparator wil trip
Description. NE555 is an IC which is widely used in timers and control circuits. A circuit for independent testing this IC is given here. Here the NE555 is wired as an astable multivibrator. When the push button switch S1 is pressed the LEDs D1 & D2 will flash alternatively. That is when output is high
Description. Commercially available voltage regulator IC’s can deliver up to 1A output current. For example 78xx series regulators are available in different voltage ratings, but in any case the current should not exceed 1A. The transistor Q1 (2N 29055) used here has 5A current capacity. The resistor R1 is used to keep the current through
Description. With this compact FM adaptor circuit plugged into the audio out of your cassete player or i Pod out put,you can listen your favorite music on your car stereo.This circuit is very useful if your car stereo doesnot have an auxillary in socket.The circuit is nothing buy an short range  FM transimitter. The FM
Description. The circuit presented her will transmit a audio tone in the FMÂ band. The circuit can be used as a tracking signal transmitter or a remote control transmitter. The circuit uses only easily available components and any one can build this. The transmitter has a range of 100m @ 9V supply, with a matching
