Showing posts with label with. Show all posts

Showing posts with label with. Show all posts

Monday, November 17, 2014

Simple Inverter with Two Transistors

The series below is a simple inverter circuit that will change the voltage of 12v dc to 220v ac, with use drive transistor 32 as its tip.
Inverter circuit is very simple and easy to assemble and is perfect for just starting to learn to assemble electronic circuits, you can use the transformer 2A to produce about 20 watts output. Do not forget to install coolers in its transistors. good luck.

Simple

Track the damage capacitors elco with ESR meter

All technicians must have the same experience that the old models of aircraft generally have several common Elco its dry or down in value, mainly found in many brands of china plane. Eco is dry can cause a variety of disorders that are sometimes difficult to trace or even be able to make certain parts do not work at all, especially if used on a circuit that works at such high frequency SMPS (Switch Mode Power Supply) and the horizontal. Elco dry technicians sometimes make headaches and time consuming when you track the damage.

Many technicians get around this problem by directly replacing all existing Elko, the Elko-regardless of whether Elko is corrupt or not. It is generally quite successful. But sometimes the quality is not good substitutes Elko, so the damaged aircraft back after use for some time. Replace all of Elko is also a problem for yourself if the circuit is improved a lot using Elko. The use of ESR-meter proved to be the most appropriate choice to solve the above problems. We suggest that ESR-meter is a must-have tool for every technician after avo-meter.

Using ESR-meter weve made themselves at a cost of less than 50,000 rupiah we recorded a lot of advantages such as:

Elko track damaged by the time more quickly because they do not need to remove the Elko (in-circuit tester) one by one.
Elko only replaced damaged
Can be used to check the quality of new and used Elko. It is certainly advantageous to utilize part of the former ex-change machine pcb. Sometimes the plane is damaged due to repeated just posted a new Elko was poor quality.
Elko that if the check using the ohm-meter sometimes the results are deceptive. Because if you checked with ESR ESR-meter turns his already large.
Can be used to check the flyback is short in the primary coil (between the B + with a pin-pin-collectors), def a short yoke, the power tranfo a short primer.
To find out if re-chargeable batteries are still good. Re-chargeable battery that is damaged ESR was generally higher when compared to a still good.
To keep track of printed lines leaking / short
By comparing the capacitors are still good, ESR-meter can be used to check the value of thousands pf capacitor.

Note:

ESR meter can not be to find Elko leak or short. Fortunately rare short Elko damage.
ESR meter to check the fit only Elko with values ranging 0.47uF and above.

Does ESR it actually?Parameters are generally owned by a Elko understood by engineers is the "maximum working voltage" and "capacitance value". In the real case there are several other parameters such as the "maximum working temperature" (85 or 105 degrees C) and "ESR" (Equivalent Series Resistance).Unless the practice is capacitive in Elko also has the characteristics of "resistive" caused by a combination of resistance to the legs, internal connections, plates and electrolyte. Thus form a resistive characteristic ESR, because if it is portrayed as if such be installed in series with the capacitance of Elko.Ideally, an Elko ESR is zero, but in practice this is impossible.Elko High voltage tends to have larger ESR than the low voltage ElkoElko with small values tend to have higher ESR values greater than Elko.Elko 105 degrees (C) tend to have higher ESR than Elko 85 degrees (C).

What Is the ESR-meter?

ESR meter is a kind of ohm-meter that can be used to measure the amount of "resistance" of Elko. Difference if the ohm-meter using a dc current (direct current) to drive the meter, then use the ESR meter ac (alternating current) with a standard frequency 150Khz. As had been explained that ideally Elko its ESR is zero. But this is not possible in practice. Elko good quality 10uF value is close to zero or more generally.

What is the cause of ESR Elko subject to change.

The first is caused because of the connection quality is poor constituents. It can be found in Elko Elko New and old.
Both are caused due to dry the liquid electrolyte due to evaporate or leak, which can be found at the old Elko. Are the consequences of large ESR Elko turned into?

Consequences of changing the value of ESR Elko

Elko is a working principle can be "in-fill and waste of" electric charge repeatedly. Thus ESR Elko-charging current will be passed this exile repeatedly in accordance with the working frequency of the circuit. And we certainly have understood that if bypassed resistor will generate heat flows in accordance with the magnitude of the current strength through resistance value and the corresponding magnitude. Similarly, the Elko with ESR, the greater the greater the ESR value of the heat arising in Elko, and the higher the frequency the greater the heat generated. This heat can eventually cause the electrolyte evaporates into a gas and seeped out, so the value of Elko will turn down. In the specific cases heat can even make Elko explode.
On a circuit that works at high frequencies Elko should have zero resistance to the high frequency signal. If the ESR of the resistance turned into Elko is no longer zero, and if the resistance value change is large enough to make the workings of the chaotic circuit.

Our experience with the use of ESR meter in the aircraft repair older model (the old plane), the first one we always do is:

Check out all the Elko with ESR-meter at the SMPS, Horizontal and Vertical and immediately replace it if the ESR problem.
Check visually (with a magnifying glass if necessary) solder-solder on the SMPS, the output Horizontal, Vertical output, and the CRT socket pcb and soldering again if there appears a problem or suspicious solder it.
Both of these were able to eliminate the difficulties that may arise and difficult to trace, so the use of ESR meter can shorten repair time.

How to use homemade ESR meter (calibration)

Once the tool is finished
Collect some old Elko is still good. Find Elko pcb traces of the plane, made in Japan or Europe the original (former aircraft engine change) because of generally good quality for use as a reference.
Grouped on the basis of a value less dar 2.2uF, 4.7uF is less than, less than and greater than 10uF 10uF.
Try using the ESR-meter to measure each group, and mark the position of the needle meter on each group
These markers can be used as a reference to the appointment of Elko ESR is still good.
If the meter needle to deviate less from the reference mark, the mean ESR Elko is not good.

Thursday, November 13, 2014

TT6061A and TT8486A sensitive touch light dimmer circuit with explanation

Using a CMOS IC TT8486A TT6061A you can build a very simple dimmer circuit which can be used to control intensity of an incandescent lamb by simply touch a contact . This electronic touch dimmer circuit can increase the light intensity of incandescent lamps in three steps.
Initially, when mains switch is ‘on,’ the bulb is ‘off’. Now, if you touch the touch plate, the bulb glows dimly. On second touch, the bulb gives medium light. At the third touch, the bulb is driven fully and another touch puts off the light.
This sensitive touch light dimmer circuit uses minimum external components and can be used for 110V or 220V AC by simply changing some external components . For touch plate, you can use a simple copper plate of 1cm×1cm (a small piece of PCB) or even the end of the lead wire. Touch plate is coupled to the touch detector through 1000pF, 2kV capacitors C4, C5 connected in series. Internally IC TT6061A’s touch signal is connected to the counter/ decoder via a resistor and clock input CK is connected to the counter/decoder via a frequency generator.

Line frequency signal is taken through R4 at pin 2 of IC TT6061A. At zero crossing, the triac (BT136) triggers to drive a 200W bulb. TT6061A

This light dimmer circuit require a 6.8 volts power supply, which is taken directly from mains through resistors R2, diode D1, capacitor C2, and zener diode and fed to power-input pin 3 of the IC. Capacitors C4, C5 connected between touch input pin 4 and touch plate remove the shock potential from the touch plate, so do not replace these capacitors with a single capacitor or with a capacitor of a lower voltage rating.

Te circuit diagram shown here is just for 110 volts ac , if you want to use this touch sensitivity light dimmer for 220 volts AC , you need to chance some components value .
For 220 volts usage you’ll need to change R1 510K TO 620K ( FOR 60HZ CHANGE TO 50HZ ) , R2 20K/1W TO 40K/2W ( FOR 110V CHANGE TO 220V ) and R6 1M TO 1.5M ( FOR 110V CHANGE TO 220V ) and also you can add an additional capacitor in series with the C4 and C5 ( capacitor used must be the same type an value ) .
S: electroniq.net/other-projects/tt8486a-tt6061a-sensitive-touch-light-dimmer.html

Tuesday, November 11, 2014

FM booster schematic circuit with explanation

A low-cost circuit of an FM booster that can be used to listen programs from distant FM stations clearly. The circuit comprises a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570 ( C2570).
This FM booster circuit is constructed using few common components ( not require some special components ) and provide a very good gain .
To calibrate this circuit you need to adjust input/output trimmers (VC1/VC2) for maximum gain.
Input coil L1 consists of four turns of 20SWG enamelled copper wire (slightly space wound) over 5mm diameter former.

It is tapped at the first turn from ground lead side. Coil L2 is similar to L1, but has only three turns.
Both of the trimmers are 22pF value .This FM radio signal booster needs to be powered by a 12 volts DC power supply

.

more at: electroniq.net/radio-frequency/fm-booster-schematic-circuit.html

Thursday, November 6, 2014

Simple 50W Hi Fi amplifier with TDA7294

The TDA7294 is a Hi-Fi amplifier and can give 100W RMS but with 10% distortion. Supplying 30 Volts you can have 50 Watts RMS with 1% distortion. Frequency range start at 16Hz and can reach 100KHz. Make sure you are using good heatsink. The chip supports mute function as well.

50W Hi-Fi amplifier Circuit Diagram
Simple

A symmetrical 30V power supply is all its need to power the unit.

Wednesday, November 5, 2014

Inverter Overload Protector With Delayed Auto Rest

An overload condition in an inverter may permanently damage the power transistor array or burn off the transformer. Some of the domestic inverters sold in the market do not feature an overload shutdown facility, while those incorporating this feature come with a price tag.the circuit presented here is an overload detector which shuts down the inverter in an overload condition.

Inverter Overload Protector With Delayed Auto Rest Circuit diagram:

Inverter

It hasthe following desirable features:

It shuts down the inverter and also provides audio-visual indication of the overload condition.
after shutdown, it automatically restarts the inverter with a delay of 6 seconds. thus, it saves the user from the inconvenience caused due to manually resetting the system or running around in darkness to reset the system at night.
It permanently shuts down the inverter and continues to give audio warning, in case there are more than three successive overloads. Under this condition, the system has to be manually reset.(Successive overload condition indicates that the inverter output is short-circuited or a heavy current is being drawn by the connected load.)

Inverter

Inverter Overload Protector With Delayed Auto Rest

The circuit uses an ammeter (0-30a) as a transducer to detect overload condition. Such an am-meter is generally present in almost all inverters. this ammeter is connected between the negative supply of the battery and the inverter, as shown in Fig. 2. the voltage developed across this ammeter, due to the flow of current, is very small. It is amplified by IC2, which is wired as a differential amplifier having a gain of 100. IC3 (NE555) is connected as a Schmitt ‘trigger’, whose output goes low when the voltage at its pin 2 exceeds 3.3V. IC4 (again an NE555 timer) is configured as a monostable multivibrator with a pulsewidth of 6 seconds. IC5 (CD4017) is a CMOS counter which counts the three overload conditions, after which the sys-tem has to be reset manually, by pressing push-to-on switch S1. the circuit can be powered from the inverter battery. In standby condition, it consumes 8-10 ma of current and around 70 mA with relay (RL1), buzzer (PZ1), and LED1 energised.

Please note the following points carefully:

Points A and B at the input of IC2 should be connected to the corresponding points (A and B respectively) across the ammeter.
Points C and D on the relay terminals have to be connected in series with the already existing ‘on’/‘off’ switch leads of inverter as shown in Fig. 1. this means that one of the two leads terminated on the existing switch has to be cut and the cut ends have to be connected to the pole and N/O contacts respectively of relay RL1.
The ammeter should be connected in series with the negative terminal of the battery and inverter, as shown in Fig. 2.Move the wiper of preset VR1 to the extreme position which is grounded. Switch ‘on’ the inverter. For a 300W inverter, connect about 250-260W of load. Now adjust VR1 slowly, until the inverter just trips or shuts down. repeat the step if necessary. Use good-quality preset with dust cover (e.g. multiturn trimpot) for reliable operation.the circuit can be easily and success-fully installed with minimum modifications to the existing inverter. all the components used are cheap and readily avail-able. the whole circuit can be assembled on a general-purpose PCB. The cost of the whole circuit including relay, buzzer, and PCB does not exceed Rs 100.

Wednesday, October 29, 2014

FM 250mW transmitter electronic Circuit diagram

A very simple FM transmitter electronic project can be designed using this circuit diagram . This FM transmitter electronic project works in FM band and it has a transmission power around 250mW ( thing that make it to work at above hundred meters ) . This FM transmitter electronic circuit is very simple and is based on some common transistors and electronic parts .
T1 transistor can be a BC107, BC171 or equivalent , and is used as an small audio preamplifier that amplify the audio signal from the microphone . Adjusting the R2 variable resistor, audio signal level from the input ( microphone ) can be adjusted until will be delivered to the T1 preamplifier (an over amplified signal applied to T1 can produce an overmodulation) . From T1 , signal is delivered to T2 which form an Hartley oscillator (frequency of this oscillator depends of C8,C9 and L1) .

fm 250mw transmitter electronic circuit project with explanation

The transmitter frequency oscillator works in FM band 87.5-108 MHz and can be set , adjusting C8 capacitor and L1 coil . L1 coil must have four turnings on a 0.8-1 mm cylinder support with a 6 mm diameter (space between each wire must be around 1 mm ) .
Antenna used for this project can be a simple telescopic antenna or a 60-70 mm Cu wire .
This electronic project can be powered from a wide range input voltage from 9 to 12 volts Dc ( but can be used even a 18 volts DC .

Saturday, October 25, 2014

Stereophonic circuit with TDA7088T

There are two signals that are directed at the so-called FM transmitter the coder (coding). Multiplexing Mpx signal has been contained, two left signals and right indirectly. Frequency modulation of a transmitter carried by the signal Mpx. The receiver output signal is obtained on Mpx and FM detector is then passed to the decoder. At the decoder do the opposite with the coder in the transmitter, because at this level produced two signals L and D.

Signal is amplified by audio amplifier dientik two, then reproduced through two speakers are the same. Now listeners can heard coming from the left half the loudspeaker is placed on the left and right half of which is placed on the right side. Situation amid the orchestra will be equal to that of the second lordspeaker reproduced, made an impression on the listener as if there.

The third loudspeaker placed midway between the left and right. Based on all these listeners have a picture of the layout space, which is significantly increased total musical impression. Electronic circuits of the portable stereophonic radio receiver with headphones reproduction, made by the IC TDA 7088T is shown in Figure the above. This is a practical embodiment of the receiver with TDA7040T decoder and two audio amplifier with TDA7050T IC.

Choke (coils) L3, L4 and L5 are HF coil allows the headphone cable is used as a receiving antenna. this fulfilled by connecting one contact of the plug-in headphones, through a 10 pF capacitor at the point where the output of the antenna is connected. Coil has a significant barrier to the signal station, preventing ground connection through capacitor 47 mF or through the TDA7050T output.

Thursday, October 23, 2014

Diagram Running LED with 4017

Running LED with 4017 complete with PCB layout. The series of 8 LED current is the basis for creating an 8-point LED. Slightly different from the running LED with IC 4017 (decade counter), 8 running this led is lit in sequence, but that has been previously flame does not die when the led is lit afterwards. 8 led to death after led to the fire-8. Meanwhile in the running LED (decade counter), the system LED lights like "point", there is only one LED that flashes between the tenth led.

Running

The main component is the IC 74LS164 (SHIFT REGISTER), with its timer is astable multivibrator circuit (using IC NE555).

The series will be more efficient when using a stable power supply (regulator) using IC Regulator 7805. Under this scheme a series of stable power supply 5 volts dc.

rangkaian

Thursday, October 9, 2014

Touch Switch Circuit with explnation

This electronic circuit uses a 555 timer as the bases of the touch switch. You can learn more about 555 timers in the Learning section on my site. When the plate is touched the 555 timer is triggered and the output on pin 3 goes high turning on the LED and the buzzer for a certain period of time. The time that the LED and the buzzer is on is based on the values of the capacitor and resistor connected to pin 6 & 7. The 10M resistor on pin 2 causes the the circuit to be very sensitive to the touch.

Wednesday, October 1, 2014

High Low Voltage Protector Circuit for Refrigerator with Timer

Back up power supply can be provided to the timer circuit to maintain time cycles during power failure as shown in Fig. 2. , By using different outputs (Q0 t to Q9, not shown) of IC 4017 or IC 0 4060, the timer can be utilised for purposes such as delayed and precise switching.

Wednesday, September 10, 2014

Automatic Night Lamp with Morning Alarm Wiring diagram Schematic

This schema automatically turns on a night lamp when bedroom light is switched off. The lamp remains ‘on’ until the light sensor senses daylight in the morning. A super-bright white LED is used as the night lamp. It gives bright and cool light in the room. When the sensor detects the daylight in the morning, a melodious morning alarm sounds. The schema is powered from a standard 0-9V transformer. Diodes D1 through D4 rectify the AC voltage and the resulting DC voltage is smoothed by C1. Regulator IC 7806 gives regulated 6V DC to the schema. A battery backup is provided to power the schema when mains fails. When mains supply is available, the 9V rechargeable battery charges via diode D5 and resistor R1 with a reasonably constant current. In the event of mains failure, the battery automatically takes up the load without any delay. Diode D5 prevents the battery from discharging backwards following the mains failure and diode D6 provides current path from the battery.

Automatic Night Lamp with Morning Alarm Circuit diagram :

Automatic Night Lamp with Morning Alarm Circuit Diagram

The schema utilises light-dependant resistors (LDRs) for sensing darkness and light in the room. The resistance of LDR is very high in darkness, which reduces to minimum when LDR is fully illuminated. LDR1 detects darkness, while LDR2 detects light in the morning. The schema is designed around the popular timer IC NE555 (IC2), which is configured as a monostable. IC2 is activated by a low pulse applied to its trigger pin 2. Once triggered, output pin 3 of IC2 goes high and remains in that position until IC2 is triggered again at its pin 2. When LDR1 is illuminated with ambient light in the room, its resistance remains low, which keeps trigger pin 2 of IC2 at a positive potential. As a result, output pin 3 of IC2 goes low and the white LED remains off. As the illumination of LDR1’s sensitive window reduces, the resistance of the device increases.

In total darkness, the specified LDR has a resistance in excess of 280 kilo-ohms. When the resistance of LDR1 increases, a short pulse is applied to trigger pin 2 of IC2 via resistor R2 (150 kilo-ohms). This activates the monostable and its output goes high, causing the white LED to glow. Low-value capacitor C2 maintains the monostable for continuous operation, eliminating the timer effect. By increasing the value of C2, the ‘on’ time of the white LED can be adjusted to a predetermined time. LDR2 and associated components generate the morning alarm at dawn. LDR2 detects the ambient light in the room at sunrise and its resistance gradually falls and transistor T1 starts conducting. When T1 conducts, melody-generator IC UM66 (IC3) gets supply voltage from the emitter of T1 and it starts producing the melody. The musical tone generated by IC3 is standard 0-9V transformer. Diodes D1 through D4 rectify the AC voltage and the resulting DC voltage is smoothed by C1. Regulator IC 7806 gives regulated 6V DC to the schema.

A battery backup is provided to power the schema when mains fails. When mains supply is available, the 9V rechargeable battery charges via diode D5 and resistor R1 with a reasonably constant current. In the event of mains failure, the battery automatically takes up the load without any delay. Diode D5 prevents the battery from discharging backwards following the mains failure and diode D6 provides current path from the battery.

The schema utilises light-dependant resistors (LDRs) for sensing darkness and light in the room. The resistance of LDR is very high in darkness, which reduces to minimum when LDR is fully illuminated. LDR1 detects darkness, while LDR2 detects light in the morning. The schema is designed around the popular timer IC NE555 (IC2), which is configured as a monostable. IC2 is activated by a low pulse applied to its trigger pin 2. Once triggered, output pin 3 of IC2 goeshigh and remains in that position until IC2 is triggered again at its pin 2. When LDR1 is illuminated with ambient light in the room, its resistance remains low, which keeps trigger pin 2 of IC2 at a positive potential. As a result, output pin 3 of IC2 goes low and the white LED remains off. As the illumination of LDR1’s sensitive window reduces, the resistance of the device increases.

In total darkness, the specified LDR has a resistance in excess of 280 kilo-ohms. When the resistance of LDR1 increases, a short pulse is applied to trigger pin 2 of IC2 via resistor R2 (150 kilo-ohms). This activates the monostable and its output goes high, causing the white LED to glow. Low-value capacitor C2 maintains the monostable for continuous operation, eliminating the timer effect. By increasing the value of C2, the ‘on’ time of the white LED can be adjusted to a predetermined time. LDR2 and associated components generate the morning alarm at dawn. LDR2 detects the ambient light in the room at sunrise and its resistance gradually falls and transistor T1 starts conducting. When T1 conducts, melody-generator IC UM66 (IC3) gets supply voltage from the emitter of T1 and it starts producing the melody. The musical tone generated by IC3 is amplified by single-transistor amplifier T2. Resistor R7 limits the current to IC3 is amplified by single-transistor amplifier T2. Resistor R7 limits the current to IC3 and zener diode ZD limits the voltage to a safer level of 3.3 volts.

The schema can be easily assembled on a general-purpose PCB. Enclose it in a good-quality plastic case with provisions for LDR and LED. Use a reflective holder for white LED to get a spotlight effect for reading. Place LDRs away from the white LED, preferably on the backside of the case, to avoid unnecessary illumination. The speaker should be small so as to make the gadget compact.

Tuesday, September 9, 2014

Build a Wire Break Alarm With Delay Wiring diagram Schematic

Here is a simple schema of wire-break alarm that activates after a delay of 15 to 30 seconds. When the thin-wire loop running across the entrance door is broken, the alarm sounds after a delay of 15 to 30 seconds, the time period set through VR1. Thus the occupants get sufficient time to lock the room from the outside and catch the thief.

The schema uses CD4060, which is a 14-stage ripple-carry binary counter/divider and oscillator. It is wired as a timer here and does not need input pulse for trigger. CD4060 gets activated as soon as the power supply is switched on. Output O13 of CD4060 goes high after the lapse of preset delay set through VR1. Transistor SL100 (T2) is wired as a switch to power the timer section built around CD4060. When the wire loop is closed, transistor T2 does not conduct. So power to the timer schema is not available and the piezobuzzer does not sound.

Wire-Break Alarm With Delay Circuit Schematic

Build

On the other hand, when the wire loop is broken by some intruder, transistor T2 conducts to power the schema and the piezobuzzer sounds after 15 to 30 seconds. IC1 can be reset by connecting the wire loop or interrupting the supply. The schema works off regulated 9V-12V. Assemble it on a general-purpose PCB and enclose in a metallic or plastic box of appropriate size. Connect piezobuzzer PZ1 through external wires and complete the installation.

Saturday, September 6, 2014

Digital DC Power supply using PWM with PIC microcontroller

IMG_20131205_123620

In our lab I saw many DC power supply which have a variable knob to regulate the output. I was dreaming to make such a project where I can regulate the voltage using push button.As I am not an industrial level expert so this project is just about a digital DC power supply of small range(5V-12V). You can press push buttons to increase or decrease output voltage.Here we use LM317 to regulate the output voltage. Output voltage is controlled by the PWM output of a pic microcontroller.An OP-AMP is required to amplify the PWM output level. The idea is simple and easy to implement in schema.

Necessary Software:

1. Proteus 7.8 Professional
2. MicroC Pro
3. PICKIT 2.61 Boot Loader

Necessary Equipment:

1. PIC 16F73
2. LCD 16x2
3. 20 MHz Oscillator
4. Variable resistor (5k Ώ, 1k Ώ, 50k Ώ)
5. 7805 Voltage Regulator
6. 7818 Voltage Regulator
7. LM317T Voltage Regulator
8. LM741 Op Amp
9. Push Button Switch
10. Resistor (1k Ώ, 220Ώ)
11. Capacitor (47, 10, 1, 0.1 uF)
12. Vero board
13. Heat Sink

Methodology:

Figure1: Block Diagram of whole system

Schematic Diagram:

Figure 2: Schematic Diagram of the schema

Description:

· LM317 can give output of 3-37V . It can change its output voltage according to the adjust pin voltage.
· PWM signal is generated from microcontroller. The signal is applied to RC low pass filter which makes a DC voltage level.
· This voltage is applied to Op Amp to get required gain.
· This amplified voltage is applied to LM317 adjust pin.
· From microcontroller we adjust the width of PWM signal. More width gives higher DC level.
· It also changes the adjust pin voltage which controls the output of LM317.

Final Output:

IMG_20131205_123620

Possible Application:

· Smooth speed control of DC motor

· Valve control of liquid and gas flow.
· Supply for different Electronic Circuit etc.

Downloads:

Download the full project file here.

Friday, September 5, 2014

4 W audio power amplifier with DC volume control

GENERAL DESCRIPTION:

The TDA1013B is an integrated audio amplifier circuit with DC volume control, encapsulated in a 9-lead single in-line (SIL) plastic package. The wide supply voltage range makes this circuit ideal for applications in mains and battery-fed apparatus such as television receivers and record players. The DC volume control stage has a logarithmic control characteristic with a range of more than 80 dB; control is by means of a DC voltage variable between 2 and 6.5 V. The audio amplifier has a well defined open loop gain and a fixed integrated closed loop. This device requires only a few external components and offers stability and performance. 4 W audio power amplifier with DC volume control

Features:

Few external components

Wide supply voltage range

Wide control range

Pin compatible with TDA1013A

Fixed gain

High signal-to-noise ratio

Thermal protection

PINNING:

power ground

amplifier output

supply voltage

electronic filter

amplifier input

control unit output

control voltage

control unit input

signal ground (substrate)

Circuit Diagram

4 W audio power amplifier with DC volume control

Datasheet for TDA1013B: Download

Thursday, September 4, 2014

Check Inductors With This Simple Q Meter

While LCR meters are readily available at reasonable cost, they do not measure the Q of an inductor. This schema enables you to measure the Q of inductors with the aid of an RF signal generator. A capacitor is connected in parallel with the inductor to form a tuned schema. By varying the frequency, you can measure the resonance frequency of the tuned schema and its -3dB bandwidth. The Q is then the resonance frequency divided by the -3dB bandwidth. Transistor Q1 is an emitter follower acting as input buffer to drive RF transformer T1. The secondary winding of T1 then drives the parallel tuned schema formed by the inductor under test (Lx), T1’s secondary and tuning capacitor VC.

The tuned schema so formed is buffered by JFET Q2 and transistor Q3 which form a cascode stage with about 3dB of gain. The JFET provides a high impedance so that the loading of the tuned schema is minimal (note: an MPF102 can be substituted if you cannot obtain a 2N5485). The RF output from Q2s collector can be monitored by an oscilloscope to easily find the point of resonance and read the frequency. Alternatively, the RF output can be read by an external frequency meter. Diodes D1 & D2 and the 5.6nF capacitors form a voltage doubler rectifier to drive a 100µA DC meter so that the resonance can be found (in the absence of an oscilloscope).

Check

Check

Trimpot VR1 provides a sensitivity adjustment for the meter. Transformer T1 is wound on a 12mm diameter ferrite toroid core. The primary winding consists of 50 turns of 0.2mm diameter enamelled copper wire, while the secondary is a single turn consisting of a strip of brass 0.5mm thick and 2.5mm wide bent into a horseshoe shape and threaded through the centre of the toroid. VC is a small AM tuning capacitor with both gangs connected in parallel.

To measure Q, the output of the RF signal generator should be around 0.5V peak. Adjust the frequency until the meters reading peaks, then adjust VR1 so that the meter reads full scale (100µA). Read the resonance frequency F0 from the frequency scale of the signal generator or better still, the reading on a frequency meter.

Next, increase the signal frequency until the meter reads 70µA and note this frequency as F2. That done, reduce the frequency on the signal generator below the resonance frequency until the meter again reads 70µA and note this frequency as F1. The Q can now be calculated as:

Q = F0/(F2 - F1)

While using a variable tuning capacitor will enable a wider range of inductors to be tested, the main advantage is estimating the distributed capacitance of the inductor as well. To do this, you have to calibrate the tuning scale with a capacitance meter, by measuring the capacitance across the tuning capacitor with no inductor connected. This is done with the unit switched off. Marking off increments of 20pF should be sufficient.

Set the tuning capacitor to say ¼ of its maximum value and note this value as C1. Adjust the RF signal generator frequency so that the inductor under test is at resonance and note this frequency as F0. Now set the RF generator frequency to half F0, adjust the tuning capacitor until resonance and note this capacitance as C2. The distributed capacitance of the inductor is (C2 - 4C1)/3.

Sunday, August 31, 2014

Fan controller with LM 741

This is fan controller schema diagram.This schema can operate the fan automatically.Here we have used supply from the transformer’s auxiliary 12V winding.we have used famous Ic LM 741 here

Note

# Build this on a PCB

Saturday, August 30, 2014

Toggle switch with Infra Red IR

Toggle switch in this article is a series of toggle switches that are controlled by infrared light. The series toggle switch is made from a combination of data flip-flop CD4013 2 units.
Receiver circuit of the infrared light signals arranged with infrared receiver as found on television remote receiver. Infrared signal from remote is used as clock signals and data to the data flip-flop first. then the second flip-flop data set as a toggle flip-flop toggle the output signal is used to drive the relay. for more details can be seen in thethe following image .

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Series Toggle Switch With Infra Red (IR) that is required to supply voltage range of 12VDC and the output of Toggle Switch With Infra Red (IR) is dapt used to turn on the lights or other electronic devices with DC or AC voltage source. Series Toggle Switch With Infra Red (IR) was isolated from the load that is placed for use as the final relay.

Thursday, August 28, 2014

Simple USB player circuit with PCM2902

Usb series player is an electronic device or electronic circuit that functions as an MP3 player that is stored on a storage device such as USB flash.

usb

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Monday, August 25, 2014

60W Hi Fi AUDIO POWER AMPLIFIER WITH MUTE STAND BY TDA2052

Features

SUPPLY VOLTAGE RANGE UP TO ±25V
SPLIT SUPPLY OPERATION
HIGH OUTPUT POWER
(UP TO 60W MUSIC POWER)
LOW DISTORTION
MUTE/STAND-BY FUNCTION
NO SWITCH ON/OFF NOISE
AC SHORT CIRCUIT PROTECTION
THERMAL SHUTDOWN
ESD PROTECTION

Circuit Diagram

Circuit Diagram for 60W Hi-Fi AUDIO POWER AMPLIFIER

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