My Circuit

Occasionally a designer needs a dual power supply to power a circuit that is operating with signals near or at ground but the only available supply is a single polarity, usually positive. Many excellent IC solutions are available but a suitable solution for many projects may be constructed from "junk box" parts. The simple circuit below will generate about 9 volts and -4 volts from a single 5 volt supply with sufficient current to power a simple op-amp circuit. The positive voltage drops to about 7 volts when supplying 7 mA and the negative voltage drops to about 3.5 volts when supplying 3.5 mA (1k loads). Although this isn't exactly a +- 15 volt supply, this is plenty of voltage and current for many op-amp circuits and will allow the output of most op-amps to swing below zero volts and will allow most op-amp inputs to measure voltages below zero volts. This circuit uses the CD4049 which is a high current version of the CD4069 which will also work with somewhat lower curr...

In tnis post we learn a simple circuit idea which may be used for producing important waveforms such as triangle waveform and square waveform. Triangular wave forms and square waves are the most sought after wave forms for the electronic hobbyist. Triangular wave forms are needed to develop PWM circuits. Both triangular and square wave forms are the tools for any electronic calibration. Here in this circuit by using a simple dual op-Amp, it is possible to get both the triangle and the square wave from the same circuit. The amplifier at the left generates the triangular wave form. The frequency of the triangular wave shall depend on the value of the capacitance and value of R. The time interval of one half-cycle is equal to R*C and it can source around 10mA of current at its output. The output of the first op-Amp is being gated at the non- inverting input of the second op-Amp which has a symmetry adjustment pot connected at its inverting input. The output of the second o...

Mini High-Voltage Generator Circuit. Here’s a project that could be useful this summer on the beach, to stop anyone touching your things left on your beach towel while you’ve gone swimming; you might equally well use it at the office or workshop when you go back to work. In a very small space, and powered by simple primary cells or rechargeable batteries, the proposed circuit generates a low-energy, high voltage of the order of around 200 to 400 V, harmless to humans, of course, but still able to give a quite nasty ‘poke’ to anyone who touches it. Quite apart from this practical aspect, this project will also prove instructional for younger hobbyists, enabling them to discover a circuit that all the ‘oldies’ who’ve worked in radio, and having enjoyed valve technology in particular, are bound to be familiar with. As the circuit diagram shows, the project is extremely simple, as it contains only a single active element, and then it’s only a fairly ordinary transistor. As shown here, it o...

How to Make a Frequency Generator . On cloud busters Fredbuster created a wonder tutorial for getting started and building your own Zapper. Fredbusters Tutorial in PDF-Based off his design here is how I made my frequency generator. Frequency Generator Circuit Diagram  Parts Needed 1 Project box with PC board included, 1 Compositor 1 micro farad, C2, I like the un-polarized because it allows you not to worry about positive an negative sides. If you do get one with a longer leg that's the positive, see schematic for proper placement. 1 Compositor .01 micro farad, C1 1 LED 1-3 volt, small red ones. Remember the longer leg is the positive, connect properly, 1 Resistor 3.3k ohm, R1, It will say it on the upper part figuring out the colors is a pain. See photo below for product ID. 1 Resistor 3.9k ohm R4 1 Resistor 4.7k ohm R5 1 Resistor 1k ohm R3 for creating a body zapper with pennies, 1 resistor for R2 see Fredbuster's PDF file for specific resistor for frequency. I use variab...

We apperceive that if a capacitor is answerable from a voltage antecedent through a resistor, an exponential waveform is produced while charging of a capaci­tor from a connected accepted antecedent produces a ramp. This is the abstraction abaft the circuit. The circuit of a access architect application timer 555 is apparent in figure. Here the resistor of previ­ous circuits is replaced by a PNP transistor that produces a connected charging current. Charging current produced by PNP constant current source is iC = Vcc-VE / RE where VE = R2 / (R1 + R2) * VCC + VBE When a trigger starts the monostable multivibrator timer 555 as shown in figure, the PNP current source forces a constant charging into the capacitor C. The voltage across the capacitor is, therefore, a ramp as illustrated in the figure. The slope of the ramp is given as

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

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). 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 used, the Luminescent Generator may be built into a very sm...

Simple circuit function generator that generates square wave and triangular or sawtooth. The frequency is determined by R and C1. For the sawtooth wave output is on pin 4 and the voltage of 6 V, while for the square wave output is on pin 3. The function generator circuit uses only one 566 and can be connected to output amplified audio. The frequency is set by potentiometer R2.   Function generator circuit using NE566 Circuit Diagram

Melody Generator using M66T This is the actual simple way to comedy a song with distinct 1.5 battery. You can body this circuit for allowance acceccories. When the allowance opened, again a song will be played.. It’s accessible and bargain right..? :D . It aloof use a distinct baby dent which will accomplish a song which already buried central the chip. Components List: C = 1uF R = 4.7KW Q = 2SC9013 About IC M66T series: The M66T series is a CMOS LSI designed melody generator IC for use in telephones and toys application. It has an on-chip ROM programmed for musical performance. Produced by CMOS technology, the device results in very low power consumption. And with built-in RC oscillator, a compact melody module can be constructed with only a few additional components. M66T pin assignment: Pin 1 (O/P) Melody Output Pin 2 (Vdd) Positive Power Supply Pin 3 (Vss) Negative Power Supply The following are the M66T series and the song generated by its series: M66T-01L : Jingle Bells +...