Showing posts with label TO. Show all posts
Showing posts with label TO. Show all posts
Microcontroller to RS 485 circuit
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Microcontroller to RS-485 circuit | RS-485 bus can carry up to 256 transceiver modules and over long distances . This is a circuit for connect microcontroller with Rs-485 bus.
Max485Max485 are low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and one receiver. Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Typical Applications The MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 transceivers are designed for bidirectional data communications on multipoint bus transmission lines.
| Microcontroller to RS-485 circuit diagrams |
- In μMAX Package: Smallest 8-Pin SO
- Slew-Rate Limited for Error-Free Data Transmission
- 0.1μA Low-Current Shutdown Mode
- Low Quiescent Current
- -7V to +12V Common-Mode Input Voltage Range
- Three-State Outputs
- 30ns Propagation Delays, 5ns Skew
- Full-Duplex and Half-Duplex Versions Available
- Operate from a Single 5V Supply
- Allows up to 128 Transceivers on the Bus
- Current- Limiting and Thermal Shutdown for Driver Overload
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.
Simple Circuit 12V to 120V DC DC Converter
When pin 1 is high transistor Q1 conducts and current flows through the upper half of T1 primary winding. When pin 2 is the transistor Q2 conducts and high current flows through the lower half of the primary coil T1. As a result of a voltage of 120 V AC are induced in the secondary of T1. This voltage is rectified with bridge D1 to provide a 120V DC output. Capacitor C2 is the DC input filter, while C3, C4 are the output filters.
Notes.
- The circuit can be assembled on a vero board.
- Q1 and Q2 require heat sink.
- Output power of this dc dc converter is around 100 watts.
- IC1 and IC2 are to be mounted on holders.
- An optional 5A fuse can be added in series to the 12V supply line.
- T1 can be a 9-0-9V /250V/3A mains transformer.
- If 3A bridge is not available make one using 1N5408 diodes.
- Out of the two Flip-Flops inside CD4013 only one is used here.
- Output of IC1 must be set to 100Hz by adjusting preset R1
Voltage to frequency converters LM231 LM331
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The LM231/LM331 family of voltage-to-frequency converters are ideally suited for use in simple low-cost circuits for analog-to-digital conversion, precision frequency-to-voltage conversion, long-term integration, linear frequency modulation or demodulation, and many other functions
| Voltage-to-frequency converters LM231/LM331 |
Features Voltage-to-frequency converters LM231/LM331:
- Guaranteed linearity 0.01% max- Improved performance in existing voltage-to-frequency
conversion applications
- Split or single supply operation
- Operates on single 5V supply
- Pulse output compatible with all logic forms
- Excellent temperature stability, ±50 ppm/°C max
- Low power dissipation, 15 mW typical at 5V
- Wide dynamic range, 100 dB min at 10 kHz full scale
- Wide range of full scale frequency, 1 Hz to 100 kHz
- Low cost
AC to DC 90 Watt Switching Adaptor
AC to DC switching adaptor circuit with best achievement ability of 90W. Switching ability accumulation is congenital application a aerial voltage ability switching regulator IC MC33374 and some added added components. The MC33374 IC is a caked aerial voltage ability switching regulators that are distinctively advised to accomplish anon from a rectified AC band source, and in flyback advocate applications.
The MC33374 switching ability adaptor combines the appropriate advocate functions with a different programmable accompaniment controller. At assorted capricious AC inputs, it is able of confined up to 6 A accepted at 15V achievement voltage. This switching ability adaptor is able of accouterment an achievement ability in balance of 150W with a anchored AC ascribe of 100V, 115V, or 230V, and in balance of 90 W with a capricious AC ascribe that ranges
12v to 5v dc dc converter circuit diagram
Power supply is needed for all of electronic circuits. Say you have a 12V power supply and you want to use it as a 5V power supply. Then use this 12v to 5v dc-dc converter circuit diagram to convert 12 volt to 5 volt. This DC converter circuit provide 5V, 1Amp at output. Here is the small schematic circuit diagram of 12volt to 5volt converter.
Circuit Diagram of 12VDC to 5VDC converter:
 |
| Fig: 12 volt to 5 volt dc converter circuit schematic |
This DC-DC converter is based on IC LM7805. The LM 7805 is a 3-terminal fixed output positive voltage regulator IC. The output current of this circuit is up to 1Amp . Use a heat sink with LM7805 to protect the IC from overheating.
100 watt inverter schematic diagram – 12 Volt to 220 Volt
Here this is a simplest circuit for 100 watt inverter for generating 220vAC from 12vDC. I say simplest because here in this inverter circuit a minimum number of components are used to design the schematic, which is quite difficult to make a circuit like this with further fewer components.
This 100W inverter circuit works great for small loads like a fan or 2-3 bulbs/lamps. In this circuit as IC1 we used a CD 4047 IC to generate 100Hz frequency (180 degree out of phase). CD 4047 IC is from Texas Instruments. It is mostly used as Astable/Monostable signal generator device. In this circuit it is triggered as astable multivibrator by the capacitor C1 between the Pin 1 and 3 of CD4047. And VR1 is used to adjust the frequency of signal.
Four 2N3055 transistors are used to amplify the pulse trains that are pre-amplified by two TIP122 transistors. There used three transistors for each side (half cycle), one TIP122 & two 2N3055 transistor to drive the output transformer (TX in circuit). Four 2N3055 transistors are used as driving transistor. An inverters maximum output power depends on two factors; one is the max current rating of transformer’s primary winding and other factor is the current rating of driver transistors.
Transformer: Use a 12v-0-12v, 10A step-down transformer in reverse. That’s mean secondary winding (12v-0-12v) will be the primary and primary winding (220VAC side) will be the secondary (output). So that it will worked like a step-up transformer. You can also use a 5A transformer instead of 10A, if you couldn’t have 10A. But the output power will decrease to 60 Watt.
+12VDC: A good quality 12V car battery could be used for DC 12V.
100 watt inverter schematic diagram
 |
| Fig: Schematic diagram of 100W inverter |
Four 2N3055 transistors are used to amplify the pulse trains that are pre-amplified by two TIP122 transistors. There used three transistors for each side (half cycle), one TIP122 & two 2N3055 transistor to drive the output transformer (TX in circuit). Four 2N3055 transistors are used as driving transistor. An inverters maximum output power depends on two factors; one is the max current rating of transformer’s primary winding and other factor is the current rating of driver transistors.
Transformer: Use a 12v-0-12v, 10A step-down transformer in reverse. That’s mean secondary winding (12v-0-12v) will be the primary and primary winding (220VAC side) will be the secondary (output). So that it will worked like a step-up transformer. You can also use a 5A transformer instead of 10A, if you couldn’t have 10A. But the output power will decrease to 60 Watt.
+12VDC: A good quality 12V car battery could be used for DC 12V.
Parts list of 100watt inverter:
VR1 = 250K (Variable resistor/POT)
R1, R2 = 4.7K-1/4W Resistor
R3, R4, R5, R6 = 0.1R-5W
C1 = 0.022uF
C2 = 220uF-25V
D1 = BY127 Diode
D2 = 9.1V Zener Diode
Q1, Q4 = TIP122 Transistor
Q2, Q3, Q5, Q6 = 2N3055 Transistor
F1 = 10A Fuse
IC1 = CD4047
TX = 12-0-12V, 10A Step-down Transformer
R1, R2 = 4.7K-1/4W Resistor
R3, R4, R5, R6 = 0.1R-5W
C1 = 0.022uF
C2 = 220uF-25V
D1 = BY127 Diode
D2 = 9.1V Zener Diode
Q1, Q4 = TIP122 Transistor
Q2, Q3, Q5, Q6 = 2N3055 Transistor
F1 = 10A Fuse
IC1 = CD4047
TX = 12-0-12V, 10A Step-down Transformer
IC 7805 7905 based Power Supply 5V to 25V 5V to 25V 1A
Here is Circuit Power Supply Regulator Adjustable Voltage Output +5 to +25V, -5V to -25V 1A ,Use IC 7805 for +Vout and IC 7905 for -Vout.
VR1 for Adjustable + Volt output,VR2 for adjustable -volt output.
USB Powered Wireless FM Transmitter Circuit FM Transmitter
Here’s a Wireless FM transmitter circuit powered from USB ports that could be used to play audio files on a standard VHF FM radio. The transmitter circuit use no coils that have to be wound. This FM transmitter can be used to listen to your own music throughout your home. When this FM transmitter used in the car, there is no need for a separate input to the car stereo to play back the music files from your MP3 player. This FM transmitter use a chip made by Maxim Integrated Products, the MAX2606 [1]. This IC from the MAX2605-MAX2609 series has been specifically designed for low-noise RF applications with a fixed frequency. The VCO (Voltage Controlled Oscillator) in this IC uses a Colpitts oscillator circuit. The variable-capacitance (varicap) diode and feedback capacitors for the tuning have also been integrated on this chip, so that you only need an external inductor to fix the central oscillator frequency.
It is possible to fine-tune the frequency by varying the voltage to the varicap. Not much is demanded of the inductor, a type with a relatively low Q factor (35 to 40) is sufficient according to Maxim. The supply voltage to the IC should be between 2.7 and 5.5 V, the current consumption is between 2 and 4 mA. With values like these it seemed a good idea to supply the circuit with power from a USB port.A common-mode choke is connected in series with the USB connections in order to avoid interference between the circuit and the PC supply. There is not much else to the circuit. The stereo signal connected to K1 is combined via R1 and R2 and is then passed via volume control P1 to the Tune input of IC1, where it causes the carrier wave to be frequency modulated. Filter R6/C7 is used to restrict the bandwidth of the audio signal. The setting of the frequency (across the whole VHF FM broadcast band) is done with P2, which is connected to the 5 V supply voltage.
The transmitter PCB designed uses resistors and capacitors with 0805 SMD packaging. The size of the board is only 41.2 x 17.9 mm, which is practically dongle-sized. For the aerial an almost straight copper track has been placed at the edge of the board. In practice we achieved a range of about 6 metres (18 feet) with this. There is also room for a 5-way SIL header on the board. Here we find the inputs to the 3.5 mm jack plug, the input to P1 and the supply voltage. The latter permits the circuit to be powered independently from the mains supply, via for example three AA batteries or a Lithium button cell. Inductor L1 in the prototype is a type made by Murata that has a fairly high Q factor: minimum 60 at 100 MHz.
P1 has the opposite effect to what you would expect (clockwise reduces the volume), because this made the board layout much easier. The deviation and audio bandwidth varies with the setting of P1. The maximum sensitivity of the audio input is fairly large. With P1 set to its maximum level, a stereo input of 10 mVrms is sufficient for the sound on the radio to remain clear. This also depends on the setting of the VCO. With a higher tuning voltage the input signal may be almost twice as large (see VCO tuning curve in the data sheet). Above that level some audible distortion becomes apparent. If the attenuation can’t be easily set by P1, you can increase the values of R1 and R2 without any problems.Measurements with an RF analyzer showed that the third harmonic had a strong presence in the transmitted spectrum (about 10 dB below the fundamental frequency). This should really have been much lower. With a low-impedance source connected to both inputs the bandwidth varies from 13.1 kHz (P1 at maximum) to 57 kHz (with the wiper of P1 set to 1/10).
In this circuit the pre-emphasis of the input is missing. Radios in Europe have a built-in de-emphasis network of 50 ?s (75 ?s in the US). The sound from the radio will therefore sound noticeably muffled. To correct this, and also to stop a stereo receiver from mistakenly reacting to a 19 kHz component in the audio signal, an enhancement circuit is published elsewhere in this issue (Pre-emphasis for FM Transmitter, also with a PCB). Author: Mathieu Coustans, Elektor Magazine, 2009
MP3 FM Transmitter Parts List
Resistors (all SMD 0805)
R1,R2 = 22k?
R3 = 4k?7
R4,R5 = 1k?
R6 = 270?
P1 = 10k? preset, SMD (TS53YJ103MR10 Vishay Sfernice, Farnell # 1557933)
P2 = 100k? preset, SMD(TS53YJ104MR10 Vishay Sfernice, Farnell # 1557934)
Capacitors (all SMD 0805)
C1,C2,C5 = 4?F7 10V
C3,C8 = 100nF
C4,C7 = 2nF2
C6 = 470nF
Inductors
L1 = 390nF, SMD 1206 (LQH31HNR39K03L Murata, Farnell # 1515418)
L2 = 2200? @ 100MHz, SMD, common-mode choke, 1206 type(DLW31SN222SQ2L Murata, Farnell #1515599)
Semiconductors
IC1 = MAX2606EUT+, SMD SOT23-6 (Maxim Integrated Products)
Miscellaneous
K1 = 3.5mm stereo audio jack SMD (SJ1-3513-SMT
CUI Inc, DIGI-Key # CP1-3513SJCT-ND)
K2 = 5-pin header (only required in combination with 090305-I pre-emphasis circuit)
K3 = USB connector type A, SMD (2410 07 Lumberg, Farnell # 1308875)
Introduction to Amplifier
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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.
4-Bit Analogue to Digital Converter Circuit Diagram
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")
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.
Simple 240VAC TO 5VDC POWER SUPPLY
This is simple way to power some 5v logic from a 240vac source. If a 120vac power adapter is used, the circuit will also work for 120vac power lines.
240VAC TO 5VDC POWER SUPPLY,
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