My Light Diagram

Diagram for a Sine Wave Generator This is a circuit for generating a sine wave from a single operational amplifier. The feedback loop of the op amp in this circuit (741) consists of a twin-T filter connected between its output and its inverting input. Positive feedback for oscillation is provided by R2.    The twin-T filter (see Figure 2) is a passive notch filter composed of two T-networks, with maximum attenuation occurring at fn = 1/(2πRC) .  One of these T networks has one resistor and two capacitors, while the other has two resistors and one capacitor.    At the notch frequency fn of the twin-T filter, the total phase shift around the loop gain of this op amp circuit is zero, which satisfies the requirement for oscillation. This is why the circuit generates a sine wave with a frequency equal to fn = 1/(2πRC) .    Note that variable resistor R3 in the circuit needs to be adjusted (in relation to the chosen value for R) until oscillatio...

This single-IC TV pattern generator is useful for fault finding in TV sets. You can correct the alignment of the timing circuits of the TV set with the help of this circuit. The vertical stripes (bars) produced by the pattern generator on the TV screen help you align the vertical scanning synchronisation circuit of the receiver. To test the TV set, you need to connect the video and audio outputs of the circuit to the respective inputs of the TV set one by one. If the video section of the TV set is working the circuit generates vertical white lines on the TV screen, and if the audio section is working you hear sound from the TV’s speakers. You can also adjust the width of vertical lines. TV Pattern Generator Circuit Diagram The circuit uses hex Schmitt inverter IC CD40106 (IC1). NOT gate N1 generates horizontally synchronised (Hsync) pulses for the PAL video signal. Presets VR1 and VR2 are used to control the ‘on’ and ‘off’ time durations of the oscillator, respectively. For PAL, you ne...

This regulator was designed for use with a  generator with a higher output voltage. This  type of generator can be found on some boats  and on vehicles for the emergency services.  They are really just an adapted version of the  standard alternator normally found in cars.  The field winding is connected to the 12 V  (or 24 V) battery supply, whereas the generator winding is configured for the AC grid  voltage (230 V or 115 V). This AC voltage now  has to be kept stable via the 12 V field winding. Although it’s perfectly possible to use a  switching regulator for this, we deliberately  chose to use the old and trusted 723. Circuit diagram : Regulator for Three-Phase Generator Circuit Diagram The generator is a three-phase type, with the  field winding rated for 12 VDC. The output voltage of the generator depends on its revs  and the current through the field winding.  Since the output voltage is relatively high, it  is fed via opto-couplers to the 723, which is  used in a standard co...

This little aid was originally designed to test the Shutter Time Meter. This meter was specifically designed for ‘analogue’ SLR cameras. In order to measure the exposure time of a camera accurately, it will first have to be checked with a well-defined signal first. This circuit was designed for that purpose. But the circuit can also be used if you need a well-defined pulse for some other purpose. The circuit is build around a trio of standard logic ICs. Firstly a 74HC4060 (IC1) is used to provide a quartz crystal accurate reference for the duration of the pulses. For the crystal frequency we choose the common 4.096 MHz value. Picture of the project: To test all the ranges of the shutter time meter, we choose three different pulse lengths in three different decades, namely: 1 / 2 / 4 / 10 / 20 / 40 / 100 / 200 / 400 ms. With jumper J1 you select a frequency of 1000, 500 or 250 Hz (see table). The frequency is then passed on to J2 and the dual decade counter IC2 (a 4518). This does not n...

Here is the simplest melody generator circuit you can make using an IC.The UM66 series are CMOS IC’s designed for using in calling bell, phone and toys. It has a built in ROM programmed for playing music. The device has very low power consumption.Thanks for the CMOS technology.The melody will be available at pin3 of UM66 and here it is amplified by using Q1 to drive the speaker.Resistor R1 limits the base current of Q1 within the safe values.Capacitor C1 is meant for noise suppression. Parts: R1 = 4.7K IC = UM66T Q1 = 2N2222 C1 = 10uF-16v S1 = On/Off Switch B1 = 1.5 - 4.5 Battery SP = 2R Speaker Notes: Power supply must be between 1.5V & 4.5V .Do not exceed 4.5 V. Speaker can be driven with external NPN transistor. Melody begins from the first note if power is reseted. Assemble the circuit on a good quality common board.

This is a simple 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). 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, t...

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 ...

This is a short  High Voltage Generator Circuit Diagram of a high voltage generator and can be mounted in a small space and powered by rechargeable or simple batteries, the circuit generates a voltage low current but a high turn-on of about 200 to 400 V harmless to humans, of course, but is able to give a pretty nasty shock.   High Voltage Generator Circuit Diagram Here is a project that could be useful this summer on the beach, to prevent anyone touching your things left on your beach towel while you was swimming, you can equally well use it in the office or workshop when you return to work. It operates as a low frequency oscillator, which makes it possible to convert the battery voltage into a DC voltage alternating current that can be enhanced through the transformer.  Using a transformer with center tap as herein makes possible the construction of a Hartley oscillator transistor T1 around The output voltage can be used directly through R2 and R3 current limiting...

The hobby circuit below uses an unusual method to generate about 12,000 volts with about 5uA of current. Two SCRs form two pulse generator circuits. The two SCRs discharge a 0.047uF a 400v capacitor through a xenon lamp trigger coil at 120 times a second. The high voltage pulses produced at the secondary of the trigger coil are rectified using two 6KV damper diodes. The voltage doubler circuit at the secondary of the trigger coil charges up two high voltage disc capacitors up to about 12KV. Although this circuit can’t produce a lot of current be very careful with it. A 12KV spark can jump about 0.75 of an inch so the electronic circuit needs to be carefully wired with lots of space between components. Source: DiscoverCircuits

This is another wonderful circuit based on IC 555, although this simple signal generator is capable of generating square wave signals, sine and sawtooth, and an adjustment of the output level. This signal generator uses besides IC 555 transistor BC 547B and two and a half dozen basic components such as resistors and capacitors. Signal Generator with 555 Circuit Diagram

 This is a Simple Baud Rate Generator Circuit Project. In this article, an RC oscillator is used as a baud rate generator. If you can calibrate the frequency of such a circuit sufficiently accurately (within a few percent) using a frequency meter, it will work very well. However, it may well drift a bit after some time, and then…. Consequently, here we present a small crystal-controlled oscillator. If you start with a crystal frequency of 2.45765 MHz and divide it by multiples of 2, you can very nicely obtain the well-known baud rates of 9600, 4800, 2400, 600, 300, 150 and 75. If you look closely at this series, you will see that 1200 baud is missing, since divider in the 4060 has no Q10 output!  Baud Rate Generator Circuit Diagram If you do not need 1200 baud, this is not a problem. However, seeing that 1200 baud is used in practice more often than 600 baud, we have put a divide-by-two stage in the circuit after the 4060, in the form of a 74HC74 flip-flop. This yields a simila...

This is another wonderful circuit based on IC 555, although this simple signal generator is capable of generating square wave signals, sine and sawtooth, and an adjustment of the output level. This signal generator uses besides IC 555 transistor BC 547B and two and a half dozen basic components such as resistors and capacitors. Signal Generator with 555 Circuit Diagram

This is a simple home telephone ringtone generator circuit which is built with applying only several electronic components / parts. It generates simulated telephone ringtone and requires only DC supply with 4.5V DC to 12V DC voltage. One may possibly use this circuit in ordinary intercom or phone-type intercom. The sound is pretty loud when this circuit is operated on +12V DC power supply. Even so, the volume of ring sound can be adjusted. Telephone Ringtone Generator Circuit Diagram CD4060B is chosen to produce three kinds of pulses. Preset VR1 is fine-tuned to get 0.3125Hz pulses at pin 3 of IC1. At the same time, pulses obtainable from pin 1 will be of 1.25 Hz and 20 Hz at pin 14. The three output pins of IC1 are connected to base terminals of transistors T1, T2, and T3 through resistors R1, R2, and R3, respectively. Working with a built-in oscillator-type piezobuzzer generates about 1kHz tone. In this particular circuit, the piezo-buzzer is turned ‘on’ and ‘off’ at 20 Hz for ...

Description:    This circuit uses a UM3561 IC to produce four different sound effects. 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. Author : Andy Collinson, anc@mitedu.freeserve.co.uk Source http://www.zen22142.zen.co.uk/