2 5A 1 25 To 25V Regulated Power Supply Circuit Diagram

This power supply uses an LM317J adjustable regulator and an MJ2955 pass transistor. Ql and U2 as well as Ul should be heats inked. A suitable heat-sink would typically be 4` 4` 1` fins, extruded type, because up to 65 W dissipation can occur. R8 and R9 should be 1% types or selected from 5% film types with an accurate ohmmeter. Capacitors are disc ceramic except for those with polarity marked, which are electrolytic. D1, D2—1-A, 100-PIV rectifier diode. DS1—Red LED. F1 —1,5-A, 3AG fuse in chassis-mount holder. J1, J2—Standard five-way binding post, one red, one black. M1—Milli-ammeter, 0-1 mA dc. Q1—NPN power transistor MJ2955 (Radio Shack) or equiv device with a + 70-V, 10-A, 150-W rating in a -204 case. R1, R2, R7—5-W wire-wound resistor. See Notes 3 and 4 for source, or, use 17 inches of no. 28 enam wire, single-layer wound, on a 10-KOhmhm, 1-W carbon-composition resistor for R1 and R7. For R2, use 36 inches of no. 30 enam wire on a 10-KOhmhm, 1-W carbon composition resistor (scramble wound). R-4—Panel-mount, 5-kfi, 2-W or 5-W potentiometer, carbon or wire wound (See Note 8). R8, R9—See text. 51—SPST toggle switch. 52—DPDT toggle or rotary wafer switch. T1—25.2-V, 2.75-A power transformer (see text). U1—6-A, 200 PIV bridge rectifier with heat sink. See text. U2—LM317T +1.25- to 30-V, 1.5-A 7-220 regulator. Use an LM317HVK (T0-204 case) for dc output voltage greater than 40. See text.

2.5A-1.25 To 25V Regulated Power Supply Circuit Diagram

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Serial To Parallel Converter

This converter may help if just the serial port on a personal computer is free, whereas the printer needs a parallel (Centronics) port. It converts a serial 2400 baud signal into a parallel signal. The TxD line, pin 3, CTS line, pin 8 and the DSR line, pin 6, of the serial port are used - see diagram. The CTS and DSR signals enable handshaking to be implemented. Since the computer needs real RS232 levels, an adaptation from TTL to RS232 is provided in the converter by a MAX232. This is an integrated level converter that transforms the single +5V supply into a symmetrical ±12V one.



The serial-to-parallel conversion is effected by IC1. This is essentially a programmed PIC controller that produces a Centronics compatible signal from a 2400 baud serial signal (eight data bits, no parity, one stop bit). The IC also generates the requisite control signals. If there is a delay on the Centronics port, the RS232 bitstream from the computer may be stopped via the Flow signal (pin 17). This ensures that no data is lost. The controller needs a 4 MHz ceramic resonator, X1.

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4 Bit Analogue to Digital Converter

The operation of the converter is based on the weighted adding and transferring of the analogue input levels and the digital output levels. It consists of comparators and resistors. In theory, the number of bits is unlimited, but each bit needs a comparator and several coupling resistors. The diagram shows a 4-bit version. The value of the resistors must meet the following criteria:

• R1:R2 = 1:2;
• R3:R4:R5 = 1:2:4;
• R6:R7:R8:R9 = 1:2:4:8.

The linearity of the converter depends on the degree of precision of the value of the resistors with respect to the resolution of the converter, and on the accuracy of the threshold voltage of the comparators. This threshold level must be equal, or nearly so, to half the supply voltage. Moreover, the comparators must have as low an output resistance as possible and as high an input resistance with respect to the load resistors as feasible. Any deviation from these requirements affects the linearity of the converter adversely.

Circuit diagram:

4-Bit Analogue to Digital Converter Circuit Diagram

If the value of the resistors is not too low, the use of inverters with an FET (field-effect transistor) input leads to a near-ideal situation. In the present converter, complementary metal-oxide semiconductor (CMOS) inverters are used, which, in spite of their low gain, give a reasonably good performance. If standard comparators are used, take into account the output voltage range and make sure that the potential at their non-inverting inputs is set to half the supply voltage. If high accuracy is a must, comparators Type TLC3074 or similar should be used. This type has a totem-pole output. The non-inverting inputs should be interlinked and connected to the tap of a a divider consisting of two 10 kΩ resistors across the supply lines. It is essential that the converter is driven by a low-resistance source. If necessary, this can be arranged via a suitable op amp input buffer. The converter draws a current not exceeding 5 mA.

Source :www.extremecircuits.net

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LM6142 LM6144 17 MHz RAIL TO RAIL INPUT OUTPUT OP AMP ELECTRONIC DIAGRAM

LM6142/LM6144 17 MHz RAIL-TO-RAIL INPUT-OUTPUT OP-AMP ELECTRONIC DIAGRAM

The topics discussed inside the application note including the general description, features, applications (such as battery operated instrumentation, depth sounders/fish finders, barcode scanners, wireless communications, rail-to-rail in-out instrumentation amps), connection diagrams, absolute maximum ratings, operating ratings, 5V DC electrical characteristics, 5V AC electrical characteristics, 2.7V AC/DC electrical characteristics, 24V electrical characteristics, typical performance characteristics, LM6142/LM6144 application ideas (enhanced slew rate, driving capacitive loads), typical applications (fish finder/depth sounder, analog to digital converter buffer, 3 op amp instrumentation amp with rail-to-rail input and output, spice macromodel),ordering information, physical dimensions, and many more.

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Introduction to Amplifier Rise

Amplification is the method of increasing the amplitude of a AC signal current or voltage such as audio signal for sound or video signal for a television picture. The amplifier allows a small input signal to control a bigger amount of power in the output circuit. The output signal is a replica of the original input signal but has higher amplitude.

Amplification is necessary as in most applications, the signal is weak to be used directly. For example, an audio output of 1mV from a microphone is unable to drive a loud speaker which requires a few volts to operate. Hence, the signal require to be amplified to a few volts before it can be fed in to the loud speaker.

NP N Transistor Circuit Configurations

An example of different type of transistor configurations in the circuit is as shown in Figure one below.

(1) The common emitter(CE) circuit makes use of emitter as its common electrode. The input signal is applied to the base and the amplified output is taken from the collector. This is the usually use because its the best combination of current gain & voltage gain.

(2) The common base (CB) circuit makes use of base as its common electrode. The input signal is applied to the emitter & the amplified output is taken from the collector. The comparatively high emitter current compared to the base current ends in low input impedance value. For this reason, the CB circuit is never used.

(3) The common collector (CC) circuit makes use of collector as its common electrode. The input signal is applied to the base & the amplified output is taken from the emitter. This circuit is also called an emitter follower. This name means that the output signal voltage at the emitter follows the input signal at the base with the same phase but less amplitude. The voltage gain is less than one & is usually used for impedance matching. Its high input at the base as a load for the earlier circuit & low output impedance at the emitter as a signal source for the next circuit.

Classes

They can be classified in to classes A, B, C & AB. They are defined based on the percent of the cycle of input signal that can produce output current.

In Class A, the output current flows for the full cycle of 360 degree of input signal. The distortion is the lowest with around 5% to 10% &an efficiency of 20% to 40%. In general, most tiny signal operate class A

In Class C, the output current flows for less than half of the input cycle. Typical operation is 120 degree of input current in the coursework of the positive half cycle of the input current. This class has an efficiency of 80% but has the highest distortion. This class is usually used for RF amplification with a tuned circuit in the output.

In Class B, the output current flows for half of the input cycle which is around 180 degree. Class B operation lies between class A & class C. Classes B are usually connected in pairs & in such a circuit called push-pull amplifier. The push pull is often used for audio power output to a loud speaker.

In Class AB, it offers a compromise between the low distortion of class A & the higher power of class B. It is usually used for push pull audio power amplifiers.

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Simple 50 to 300 MHz Colpitts Oscillator Diagram

Simple high efficiency Colpitts oscillator .In the higher frequency ranges, above 50 MHz, Colpitts oscillators are used because stray circuit capacitance will be in parallel with desired feedback capacitance and not cause undesirable spurious resonances that might occur with the tapped coil Hartley design.

The FM VCO shown is a grounded base design with feedback from collector to emitter. A Colpitts oscillator is one of a number of designs for electronic oscillator circuits using the combination of an inductance with a capacitor for frequency determination.As you can see in the circuit diagram , this electronic project require few electronic parts an provide a 50 MHz-300MHz VCO with a tuning range of 2:1 .

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Let’s to build a mini organ keyboard circuit using UM3511

The previous
day my son said ” A friend has a mini organ. Casio SA-76 44 Key Mini
Keyboard, Orange It is Good quality but expensive.
My son would have
the same. But I said, as we are the Electronic inventor, to try to
create their own. We are proud and cheaper too.
You might like this
mini organ keyboard circuit certainly. Because in addition to the
simple, the price is not expensive, effective really worthwhile.
You may consider the main features of the circuit, as follows.
1. Can works with DC voltage in rang 3-12 Volt by low current consumption.
2. There are the music playback up to 15 keys, or a note from G3-G5.
3. Can be programmed to play. Repeat for up to 47 notes.
4. Can act as a music source by up to 15 songs.(Simple carbohydrates. Press any key. To select the desired song.)
How circuit works
In the heart of the circuit is the UM3511
-IC is designed to act this purpose

-Internal IC consists of a lot. We do not need to explain the
operation of the circuit Internal this IC. Our job only assembly
equipment used in the first the circuit to be completed.


-From circuit in figure 1 will see that we can connect a output of
pin 5 on the UM3511-IC to drive a transistor output to emit loud sound
out to the speakers directly.
-For the variable resistor-VR1 act as
determine a frequency of the oscillator circuit. When we created
successfully. Should be adjusted to the correct value. When adjusted,
you may use the normal resistor instead.
-The switch-S1 as an
option act the work of circuit that music will be played by the
application of the factory, or will play music as we have played own.
From pushing keyboard as by various notes.
For a list of songs that can be programmed from the factory. Which will play out as We have push switch as follows.
G3 Hush little baby
A3 Twinkle Little Star
C4 Dream of Home and Mother
D4 Christmas Carol
E4 Are You Sleeping
F4 The Famer in the Dell
G4 In a Persian Market
A4 Mary Had a Little Lamp
B4 Long Long Ago
C5 Santa Lucia
D5 Little Brown Jug
E5 Butterfly
F5 The Train is Running Fast
G5 Close Encounters of the Third Kind
How to build and setting
Suppose that you want to play Santa Lucia, it may be done as follows.
1. Hit the switch S1 to the program.
2. Press the C5 keyboard switch.
Only this time, it will play the music you want to finish it, it will stop automatically.

For convenience we have on the power supply is designed for the 5 volt
dc regulator circuit. To be applied to the input voltage from 6 volt to
24 volt. It also allows the voltage to be smooth, no hum at play.

Figure 2 the pcb layout of a mini organ keyboard circuit using UM3511
All components except the transformer and speaker. We can assemble onto the PCB. As shown in Figure 2.

For keyboard switch because we want you to get a feel for the playing.
As the organ of the fact that selling in the shop. We chose to use a
computer key switches.

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Frequency to Voltage Converter Circuit

IC LM2917 Frequency to Voltage Converter

IC LM2917 IC chip is designed specifically as a Frequency to Voltage Converter or Frequency to Voltage converter. In its use to applications Frequency to Voltage Converter IC LM2917 requires few external components. 

There are several examples of applications of Frequency to Voltage Converter IC LM2917 datasheet that is included in the LM2917 IC. In this article series Frequency to Voltage Converter IC also taken from the LM2917 datasheet. The advantages of single chip LM2917 Frequency to Voltage Converter is able to provide instantaneous volt output o at time of frequency change 0 Hz. Very easy to apply in measuring the output frequency with the formulation of single-chip Frequency to Voltage Converter VOUT = FIN x VCC x R1 x C1.

Then the single-chip LM2917 Frequency to Voltage Converter This configuration requires only the RC only in frequency doubling. And has an internal zener regulator to aimlessly accuracy and stability in frequency-to-voltage conversion process.

Application circuit Figure IC LM2917 as Frequency to Voltage Converter

Feature-owned single-chip LM2917 Frequency to Voltage Converter

Reference to ground directly with variable reluctance

Op Amp / Comparator with transistor output

50 mA maximum output currents for application directly to the load

Frequency doubling for low ripel

Buid in zener

Linear output ± 0.3%

Application single chip LM2917 Frequency to Voltage Converter

Frequency to Voltage Converter

Rotation speed sensor applications

Speedometer

Tachometer

Cruise Control

Cluth Control

And other applications associated with the measurement of rotation speed or frequency measurements.

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