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Simple circuitry, low distortion, battery operated Variable, low impedance output up to 1V RMS Circuit diagram Parts: R1 5K6 1/4W Resistor R2 1K8 1/4W Resistor R3,R4 15K 1/4W Resistors R5 500R 1/2W Trimmer Cermet R6 330R 1/4W Resistor R7 470R Linear Potentiometer C1,C2 10nF 63V Polyester Capacitors C3 100µF 25V Electrolytic Capacitor C4 470nF 63V Polyester Capacitor Q1,Q2 BC238 25V 100mA NPN Transistors LP1 12V 40mA Lamp (See Notes) J1 Phono chassis Socket SW1 SPST Slider Switch B1 9V PP3 Clip for 9V PP3 Battery Circuit description: This circuit generates a good 1KHz sinewave using the inverted Wien bridge configuration (C1-R3 & C2-R4). Features a variable output, low distortion and low output impedance in order to obtain good overload capability. A small filament lamp ensures a stable long term output amplitude waveform. Useful to test the Audio Millivoltmeter, Audio Power Meter and other audio circuits published in this site. Notes: The lamp must be a low current type (12V 40-50m...

Function Generator The function generator is a versatile instrument that gives a number of different waveforms at the output with their frequencies that can be adjusted over a wide range. The most commonly used waveforms are sine wave, square wave, triangular wave and the saw tooth wave. Different output signals from the function generator may be available simultaneously. Picture of Function Generator The fig shows the block diagram of a function generator. Here two constant current sources are used to feed the integrator circuit. When the circuit is switched ON, the upper constant current source sends a constant current into the integrator and the output of the integrator is connected to comparator. When the integrator output reaches a predetermined level, the comparator changes the state i.e. the upper constant current source is cut OFF while the lower source is switched ON. This current source passes a current in the reverse direction and the voltage at the integrator output decreas...

Because of energy crisis Load shedding may be a common problem in several countries.. Sudden power fluctuations, surge and high voltage may spoil sophisticated household appliances like TV, VCR, VCP and music system. This circuit provides protection against these problems and automatically changes the power supply from Generator output to mains supply and also switches off the generator. Circuit descriptions This circuit is self explanatory. When lines supply voltage crosses the preset level, Zener diode ZD4 break down and thus transistor T2 conducts, T3 does not conduct, causing the relay to de-energise. Voltage surge at the time of power resumption is protected by the delay circuit around transistor T1. All the portable petrol and kerosene generators have a connection from CDI. To stop the engine of the generator-set, this connection is to be grounded momentarily (through the switch). This lead is to be connected with the ground through the N/C point of the relay. Auto Changeover ...

2MHz Square Wave Generator Circuit Diagram. With the values shown the circuit generates a 2-MHz symmetrical square wave. Changing capacitors Cl and C2 to 0.01 µ¥ results in a frequency of 500 Hz. For the particular integrated circuits and power supply voltages (5.0 V), the reliable operating range of Rl = R2 is 2 k ohm to 4 k ohm. 2MHz Square Wave Generator Circuit Diagram

The Tri-Waveform Generator can be used for a number of different uses. The one that I use it for is a signal generator to test circuits. The frequency range is 20 to 20khz. and can be adjusted by R1. The duty cycle or the time that the waveform is high and the time that the waveform is low can be adjusted by R4. The purpose of R2 and R3 are to clean up any distortion on the sine wave output. To do this you must hook up the sine wave output to and oscilloscope and adjust R2 & R3 to make the sine wave as accurate as possible. Source by : Streampowers

High Frequency Waveform Generator Circuit Diagram High frequency waveform generator is very useful in electronic experiment and design. This circuit generate sine wave oscillation, but actually we can modify the circuit to generate triangle or square wave function. The core of this waveform generator is MAX038. This integrated circuit chip gives complete function to build a waveform generator/function generator. The circuit can be used to generate square wave, triangle, or sine wave by programming the pin inputs (A0:pin 3, A1:pin 4). A0 A1 WAVEFORM X 1 Sine wave 0 0 Square wave 1 0 Triangle wave The frequency can be controlled using current. If we disconnect the 20k RIN from REF (pin 1) and connect it to a DAC, then we can control the frequency using microcontroller or digital interface. We can even control the chip using a quartz crystal (PLL) by controlling the current using a phase comparator output that compares the sync output (pin 14 of MAX038) and a reference clock from quartz...

This circuit generates a two-tone effect very much alike the cuckoo song. It can be used for door-bells or other purposes thanks to a built-in audio amplifier and loudspeaker. Used as a sound effect generator it can be connected to external amplifiers, tape recorders etc. In this case, the built-in audio amplifier and loudspeaker may be omitted and the output taken across C8 and ground. There are two options: free running, when SW1 is left open, and one-shot, when SW1 is closed. In this case a two-tone cuckoo song will be generated at each P1 pressing. Circuit diagram: Parts: R1,R5___________1K 1/4W Resistors R2_____________50K 1/2W Trimmer Cermet R3______________8K2 1/4W Resistor R4_____________82K 1/4W Resistor R6______________1M 1/4W Resistor R7,R17,R20,R21_22K 1/4W Resistors R8,R10,R11,R19_10K 1/4W Resistors R9____________150K 1/4W Resistor R12_____________4K7 1/4W Resistor R13___________100K 1/4W Resistor R14___________220R 1/4W Resistor R15,R22________20K 1/2W Trimmers Cermet R16...

This is a generator circuit which is very useful, it simultaneously generates two types of noise, pink and white. The noise generator is a circuit that produces electrical noise . Noise generators are used to test , measure noise , frequency response , and other parameters . The circuit described here is based on the operational amplifier 741 .  Dual White Noise and Pink Noise Generator Circuit Diagram

Pulse generator circuit above is a pulse generator that uses logic gates. There are so many types and variations that can generate a series of pulses. The simplest is the use of transistors or often called a flip-flop. There also are using integrated circuit such as IC 555. There's more to exploit the resonance of the capacitor and inductor relationship as oscillators. To be sure whatever form and whatever the circuit components used must be able to generate electric waves which have a peak voltage (logic 1) and valleys (logic 0) is continuous. Any variation of pulse generator circuit design has advantages and disadvantages of each, just how your decision for the appropriate circuit. For example to create a clock signal for a simple utility that you can only take advantage of the transistor but if you need a more accurate clock signal and form a perfect balance you can use IC Astable or logic gates. Or perhaps you need a signal with very high frequency (up to MHz) you can use a com...

This is a simple project of Preamplifier for RF Sweep Generator Circuit diagram. The RF sweep frequency generator (‘wobbu-lator’) published in the October 2008 issue of Elektor has a receiver option that allows the instrument to be used as a direct conversion receiver. This receiver does however have a noise floor of only –80 dBm, which really should have been –-107 dBm to obtain a sensitivity of 1 µV. So, for a good receiver sommore gain is required. A wideband amplifie however, generates a lot of additional noisas well and as a consequence will not resuin much of an improvement.  As an experiment, the author developed a selective receiver with a bandwidth of about 4 MHz. Because a gain of at least 35 dB is required, the preamplifier consists of two amplifying elements.  The input amplifier is designed around a dual gate MOSFET, type BF982. This component produces relatively little noise but pro-vides a lot of gain. The output stage uses a BFR91A for some additional gain. Pre...

One tool that I’ve been missing at my lab at home is function generator. They tend to be a bit expensive, so I haven’t bought one. I thought this might be a good opportunity to try and make one myself. I found a pretty common DDS (direct digital synthesis) chip, called AD9833. Then just strap a USB-enabled AVR micro there and maybe some analog electronics. This board doesn’t do any of the special analog magic to allow for variable amplitude or offset for the signal. The output is fixed to 0-4v. I’m planning to make another completely analog board for adjusting amplitude and offset.

Luminescent Generator Circuit diagram. When spun rapidly between the fingers, a bipolar stepper motor will generate around 10VAC. If this is stepped up with a small 240V to 6-0-6V transformer in reverse (with series connected secondaries), a small bipolar stepper motor is capable of powering a standard 5cm by 6cm luminescent sheet at full brightness. These are designed to be powered from 20V to 200VAC (typically 115VAC), producing 1.5 candelas of light - which will dimly light the average room, or adequately light a camp table. They are manufactured by Seikosha (RS Components Cat. 267-8726). Luminescent Generator Circuit diagram: Luminescent Generator Circuit Diagram The transformer should be a small one (around 100mA or so), otherwise efficiency is compromised. The wires of the motor's two phases are usually paired white & yellow and red & blue. Just one of these phases is employed in the circuit. If a small bipolar stepper motor from a discarded 3.5-inch disk drive is us...

This is the simple Tri-Waveform Generator Circuit Diagram. The Tri-Waveform Generator can be used for a number of different uses. The one that I use it for is a signal generator to test circuits. The frequency range is 20 to 20khz. and can be adjusted by R1. The duty cycle or the time that the waveform is high and the time that the waveform is low can be adjusted by R4. Tri-Waveform Generator Circuit Diagram The purpose of R2 and R3 are to clean up any distortion on the sine wave output. To do this you must hook up the sine wave output to and oscilloscope and adjust R2 & R3 to make the sine wave as accurate as possible.

Dual-purpose test-instrument, Very simple circuitry, 1.5V Battery-operated. This simple circuit generates narrow pulses at about 700-800Hz frequency. The pulses, containing harmonics up to the MHz region, can be injected into audio or radio-frequency stages of amplifiers, receivers and the like for testing purposes. A high-pitched tone can be heard from the speaker of the device under test when all is working properly. The clip must be connected to the ground of the device under test, touching with the probe the different stages of the circuit, starting from the last stage and going up towards the first. When the tone is no longer heard, the defective stage has been found. Connecting an earclip or headphone to J1, the circuit will automatically change into a two-stage amplifier and any audio signal coming from the device under test and picked-up by the probe will be heard through the headphones. The testing of a circuit should be made in the reverse manner, i.e. starting from the first...

A Simple Sound Effects Generator Circuit uses a UM3561 IC to produce four different sound effects. Circuit diagram : Simple Sound Effects Generator Circuit Diagram Notes: Nothing too complicated here. The IC produces all the sound effects, the output at Pin 3 being amplified by the transistor. A 64 ohm loudspeaker can be substituted in place of the 56 ohm resistor and 8 ohm loudspeaker. The 2 pole 4 way switch controls the sound effects. Position 1 (as drawn) being a Police siren, position 2 is a fire engine sound, 3 is an ambulance and position 4 is a machine gun effect. The IC is manufactured by UMC and was available from Maplin electronics code UJ45Y. At the time of writing this has now been discontinued, but they have have limited stocks available.

Here are a Simple Electronic Schematic Circuit Project of Marker Generator.  The marker generator circuit explained here is a constant- frequency oscillator driving into a CMOS divider chain. Switchable out- puts from the divider chain are selected to drive a pulse generator.  The oscillator is C1a in which R1 biases the IC into linear operation. The crystal determines the basic frequency of operation at 4 MHz in conjunction with C1, 2, 3 and 4 which appear to the crystal as one parallel capacitor. Simple Marker Generator Circuit Diagram: The capacitor C2 is  used to tune the oscillator exactly to frequency as explained in the text. The resistor R2 adds extra phase shift but also reduces the gain. Thus if the oscillator is slow in starting reducing R2 may help. The output of the oscillator is buffered from the rest of the circuit by IC1 /b. lC2 is a CMOS dual type D flip flop that divides the 4 MHz by four to provide an out put of 1 MHz, the 2 MHz also being brought out....