Wiring Material: generator

Showing posts with label generator. Show all posts

Thursday, November 13, 2014

Pulse Generator And Signal Tracer

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 stage and going down until the last stage. When nothing is heard, the defective stage has been found.

Circuit diagram:

Pulse Generator And Signal Tracer Circuit Diagram

Parts:
R1________________1M 1/4W Resistor
R2,R4_____________2K7 1/4W Resistors
R3________________150K 1/4W Resistor
C1________________2n2 630V Ceramic or Polyester Capacitor (See Notes)
C2,C3_____________4n7 63V Ceramic or Polyester Capacitors
D1_______________1N4148 75V 150mA Diode
Q1_______________BC547 45V 100mA NPN Transistor
Q2_______________BC557 45V 100mA PNP Transistor
SW1______________SPST miniature Slider Switch (See Notes)
J1_______________Stereo switched 3mm. Jack socket (See Notes)
Probe____________Metal Probe 3 to 5 cm. long
Clip______________Miniature Crocodile Clip
B1_______________1.5V Battery (AA or AAA cell etc.)Circuit operation:Q1 & Q2 form a complementary astable multivibrator, whose operating frequency is set mainly by R3, C2 & C3 values. Output pulses are taken at Q2 Collector and applied to the probe by means of decoupling capacitor C1. D1 provides a symmetrical shape for the output waveform. If an earclip or headphone jack is plugged into J1, the connection from Q2 Collector and C1 - C2 is broken by the switch incorporated into J1: in this case the circuit becomes a two-stage amplifier.Notes:

If you intend to use the circuit to test valve operated devices C1 must be a 630V type. Working with low voltage supply transistor devices the voltage of C1 can be lowered to 63 or 100V.
If instead of a short probe, you intend to connect the circuit to the device under test by means of a piece of wire longer than a few centimeters, a small ceramic capacitor (470 to 1000pF) should be added in parallel to D1 to prevent unwanted RF oscillation.
Current drawing when in Pulse-Generator mode is about 60µA and 1.2mA when in Signal-Tracer mode operation. Therefore SW1 can be omitted, provided that the earclip or headphones are unplugged when the circuit is unused.
J1 is a stereo switched jack socket wired to obtain a series connection of the two earpieces forming a stereo headphone. In this manner the circuit is loaded with a higher impedance and sensitivity will be improved.
Therefore, the higher the load impedance the more sensitive the Signal-Tracer. In any case, common 32 Ohm impedance mini-headphones suitable for walkman sets will work fine.
A crystal (high impedance) earpiece is a good solution, provided you substitute J1 with a mono switched jack socket.
The entire circuit can be easily fitted into a pen-like enclosure, with the probe protruding like a nib

Friday, October 3, 2014

Ramp Generator Circuit using NE555

We know that if a capacitor is charged from a voltage supply through a resistor, an exponential waveform is created while charging of a capacitor from a continuing current supply produces a ramp. this is the concept behind the circuit. The circuit of a ramp generator using timer 555 is shown in figure. Here the resistor of previous circuits is replaced by a PNP transistor that produces a continuing charging current.

Charging current produced by PNP constant current source is

i_C= Vcc-V_E/ R_E

where V_E= R₂/ (R1 + R2) * V_CC+ V_BE

When a trigger starts the monostable multivibrator timer 555 as shown in figure, the PNP current supply forces a continuing 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 Slope, s = I/C

Thursday, September 25, 2014

Exponential Waveform Generator Circuit

This circuit produces a waveform that decays exponentially from a set voltage to near-zero, and then rapidly resets to restart the cycle.
Initially C1 is charged to +12V, and O1, O2 are both off. The timing capacitor there discharges slowly through Rl, the exponentially decay- ing voltage appearing at low impedance at the output of unity-gain buffer RC2. R2 prevents the leakage current from O1 affecting the discharge as D1 is reverse-biased. When the voltage on Cl reaches a value just above zero that is set by R3, R4, the open collector O/P of lC‘l goes low, turning on O1 and rapidly recharging Cl. lCi ofcourse reverts to its original state almost at once, but the recharge mode is prolonged for several mil|i· seconds by the positive feedback loop through R5, C2 and O2, to ensure Cl charges fully. After this time C2 is also fully charged, and O2 turns off, turning off Ql, and allowing the slow discharge of C1 to begin again. With the component values shown each cycle lasts about ten seconds.

Monday, August 25, 2014

Build a Cuckoo Sound Generator Circuit Schematic

This schema 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.

Cuckoo Sound Generator 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____________10R 1/4W Resistor
R18___________200K 1/2W Trimmer Cermet
C1,C11_________47nF 63V Polyester or Ceramic Capacitors
C2,C10,C12____220µF 25V Electrolytic Capacitors
C3____________220nF 63V Polyester or Ceramic Capacitor
C4_____________22nF 63V Polyester or Ceramic Capacitor
C5,C6,C8,C9___100nF 63V Polyester or Ceramic Capacitors
C7,C13,C14_____10µF 63V Electrolytic Capacitors
D1,D2,D3,D6__1N4148 75V 150mA Diodes
D4,D5_________BAT46 100V 150mA Schottky-barrier Diodes
Q1,Q2_________BC547 45V 100mA NPN Transistors
IC1____________7555 or TS555CN CMos Timer IC
IC2____________4093 Quad 2 input Schmitt NAND Gate IC
IC3____________4017 Decade counter with 10 decoded outputs IC
IC4___________LM386 Audio power amplifier IC
P1_____________SPST Pushbutton
SW1____________SPST Switch
SPKR___________8 Ohm Loudspeaker

Circuit Dis....
IC1 is wired as a square wave generator and produces both tones of the cuckoo song. The frequency of the higher one (667Hz) is set by means of Trimmer R2. When IC2D output goes low, a further Trimmer (R22) is added to IC1 timing components via D6, and the lower tone (545Hz) is generated. To imitate closely the cuckoo song, the square wave output of IC1 is converted to a quasi-sinusoidal wave form by R3, R4, C3 and C4, then mixed with the white noise generated by Q1, R6.

Q2 has two purposes: it mixes the two incoming signals and gates the resulting tone, shaping its attack and decay behavior by means of the parts wired around its Emitter. IC4 is the audio power amplifier driving the speaker and R15 is the volume control. The various sound and pause timings for the schema are provided by the clock generator IC2A driving the decade counter IC3. Some output pins of this IC are gated by IC2C, IC2D and related components to drive appropriately the sound generator and the sound gate.

When SW1 is left open the schema operates in the free-running mode and the cuckoo song is generated continuously. When SW1 is closed, the schema generates two tones then stops, because a high state appears at the last output pin (#11) of the decade counter IC: therefore the count is inhibited by means of D1 feeding pin #13. The schema is reset by a positive pulse at pin #15 of IC3 when P1 is pressed.

Setup:

Best results will be obtained if the two tones frequencies are set precisely, i.e. 667Hz for the first tone and 545Hz for the second: in musical terms this interval is called a Minor Third. Obviously a digital frequency counter, if available, would be the best tool to setup R2 and R22, but you can use a musical instrument, e.g. a piano or guitar, tuning-up the notes accurately by ear.

Disconnect temporarily R22 from D6 anode.
Connect the digital frequency counter to pin 3 of IC1.
Adjust R2 in order to read 667Hz on the display.
Connect R22 to negative ground and adjust it to read 545Hz on the display.
Restore R22 - D6 connection.

Tuning by ear:

Disconnect temporarily R22 from D6 anode.
Disconnect C8 from Q2 Collector and connect it to R4, C4 and C5 junction.
Adjust R2 in order that the tone generated by the loudspeaker is at the same pitch of the reference note generated by your musical instrument. This reference note will be the E written on the stave in the fourth space when using the treble clef.
Connect R22 to negative ground and adjust it in order that the tone generated by the loudspeaker is at the same pitch of the reference note generated by your musical instrument. This second reference note will be the C-sharp written on the stave in the third space when using the treble clef.
Restore R22 - D6 and C8 to Q2 Collector connections.

Notes:

The master clock can be adjusted by means of R18.
The percentage of hiss and sound in the mixing schema, setting the tone character, can be varied changing R8 and R7 values respectively.
Any kind of dc voltage supply in the 12 - 15V range can be used, but please note that supply voltages below 12V will prevent operation of the white noise generator.
An amusing application of this schema is to use a photo-resistor in place of P1, then placing the unit near the flashing lamps of your Christmas tree. A sweet cuckoo song will be heard each time the lamp chosen will illuminate.

Source: Red Free Circuit Design

Thursday, August 21, 2014

Simple Melody Generator Wiring diagram Schematic

This is so impotent schema for you all.On the other hand this is so important schema for beginners.Here I have used IC UM66 You can get various musics when you buy UM66 with different numbers.