Circuit Schematic 434MHz RF Based Wireless Remote Control System

Eltronicschool. - This is one of the radio frequency circuit schematic for you who want to build 434MHz in this time. This is circuit schematic of  434MHz RF Based Wireless Remote Control System.

Beside we will give you circuit schematic of this 434MHz RF Based Wireless Remote Control System, we also will give you the global description of 434MHz RF Based Wireless Remote Control System from original source.

Circuit Schematic

Transmitter Circuit (Source: Electroschematic)

Reciever Circuit (Source: Electroschematic)

Component Part

1. HT12E and HT12F IC
2. RF Module with 434MHz
3. Resistors
4. Transistor
5. Relay
6. Capacitors
7. Diode

Description

Circuit schematic like in Figure 1 above is 434MHz RF Based Wireless Remote Control System. Accordingly Electroschematic site describe that this simple RF transmitter, consisting of a 434MHz license-exempt Transmitter module and an encoder IC , was designed to remotely switch simple appliances on and off. The RF part consists of a standard 434MHz transmitter module, which works at a frequency of 433.92 MHz and has a range of about 400m according to the manufacture. The transmitter module has four pins. Apart from “Data” and the “Vcc” pin, there is a common ground (GND) for data and supply. Last is the RF output (ANT) pin.

The miniature 434MHz RF receiver module receives On-Off Keyed (OOK) modulation signal and demodulates it to digital signal for the next decoder stage. Local oscillator is made of Phase Locked Loop (PLL) structure. Technically, this is an Amplitude Shift Keying (ASK) receiver module based on a single-conversion, super-heterodyne receiver architecture and incorporates an entire Phase-Locked Loop (PLL) for precise local oscillator (LO) generation. It can use in OOK / HCS / PWM modulation signal and demodulate to digital signal.

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Circuit Schematic High-band DPD Demodulator with Integrated DSA and RF Switch using IDTF1370

Eltronicschool. - This is one very useful for you, circuit schematic that called with  High-band DPD Demodulator with Integrated DSA and RF Switch using IDTF1370 look like in Figure 1 below.

In this time, we will give you global description about this  High-band DPD Demodulator with Integrated DSA and RF Switch using IDTF1370 circuit schematic and we will allow you to red more about this circuit from original source.

Circuit Schematic

Figure 1. Circuit Schematic High-band DPD Demodulator with Integrated DSA and RF Switch using IDTF1370 (Source: Electroschematics)

Component Part

1. IDTF1370
2. Coil Inductor
3. Resistors
4. Capacitors

Description

Circuit schematic like in Figure 1 above is  High-band DPD Demodulator with Integrated DSA and RF Switch using IDTF1370 circuit  that will give you high-performance DPD demodulator.

How it works

According Electroschematics site describe the IDTF1370 is a digital pre-distortion demodulator (DPD) for power amplifiers linearization in BTS transmitter that utilize the IDT zero-distortion, and glitch-free technology that offers customers an unparalleled high-performance DPD demodulator. It utilizes the technique called pre-distortion, in digital communication it is used to improve the linearity of the transmitter performance by pre-distorting a data to counteract the distortion inherent in the power amplifier. The F1370 has an RF channel range of 1300-2900MHz, it’s IF frequency ranges 20-500MHz, a typical gain of 12.5dB, +41dBm IP3o, and a High/Low side injection. The device features an integrated DPD IC for MIMO, which eliminates the need for external IF amps, baluns, switches, and DSAs thus reduce solution cost and space significantly. It has a reduction of greater that 1-Watt power consumption compared to conventional solutions.

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Circuit Schematic Low Power AM Transmitter Based on Transistor

Eltronicschool. - This is one of radio circuit schematic for you who like with transmitter project. In here we will show you one of Low Power AM Transmitter Based on Transistor circuit schematic look like in Figure 1. 

In this time, based on transistor, capacitor, and inductor components, we will give you one of global description about this circuit schematic beside we give you schematic and component list.

Circuit Schematic

Figure 1. Circuit Schematic of  Low Power AM Transmitter Based on Transistor (Source: Electroschematics)

Component Part

1. Resistors
2. Inductor
3. Capacitors

Description

Circuit schematic like in Figure 1 above is  Low Power AM Transmitter Based on Transistor. With this circuit schematic, you can build your self the basic of  Low Power AM Transmitter Based on Transistor.

How it works

According Electroschematics site describe that this transmitter is basic but allows transmission of audio to an AM radio. It consists of an RF oscillator operating in the AM broadcast band, together with a modulator stage, which mixes the incoming audio and the RF. A signal appears on the output, which has an AM component that can be picked up on a nearby AM radio receiver.

The transmitter' part consists of modulator/buffer stage Q2 and oscillator stage Q1. Q1 is biased via R1, R2, and R3. L1, C3, and C4 form the tank circuit with feedback network C3-C4 providing feedback to the emitter of Q1. RF voltage at the junction of C3 and L1 drives buffer/modulator stage Q2. Q2 is biased by base current produced by RF rectification in the base emitter junction of Q2. C6 is an RF and AF bypass capacitor. C9, C10, and L2 form the tank circuit for the collector of Q2. RF is taken from the junction of C9 and C10 and fed to a short-wire antenna. Audio is fed to modulator Q2 via C8 and isolation resistor R5 and mixes with the RF signal in the collector circuit of Q2, producing a signal that has sum and difference frequencies if the RF carrier and AF input  along with the carrier signal.

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Circuit Schematic Holtek HT12E encoder in high-density ASK R-C applications

Eltronicschool. - This is one of Radio circuit schematic categorize that titled with Circuit Schematic Holtek HT12E encoder in high-density ASK R-C applications like in Figure 1. below. 

Circuit schematic

Figure 1. Circuit Schematic Holtek HT12E encoder in high-density ASK R-C applications (Source: electroschematics)

Component Parts

1. HC221 IC
2. Holtek HT12E IC
3. Resistors
4. Capacitors
5. All components see in Figure 1 above

Description

Circuit schematic like in Figure 1 above is Circuit Schematic Holtek HT12E encoder in high-density ASK R-C applications. According Electroschematics site describe that he high-density ASK (amplitude shift keying) environment is one in which there are so many transmissions occurring at a given frequency that they occasionally collide and thus fail to get properly decoded by the targeted receivers. There are a number of potential solutions, but in this discussion we are concentrating on limiting the transmitter On-period. This is accomplished by operating the encoder IC at the maximum data rate and by limiting the transmitter On-time via a monostable multivibrator. Obviously, this is not appropriate for critical applications, but provides an inexpensive solution for many non-critical applications. For a complete mini-system, the HT12E encoder must be matched with a HT12D decoder.

• Key contact de-bounce multivibrator

The most significant problem occurs when the operator keys the encoder for an extended period of time. This essentially jams the frequency so that no other transmissions can be received. To prevent this from occurring, a monostable multivibrator keys the encoder for about 20mS. This limits the transmission to the minimum 4word data burst. To prevent the transmitter from being keyed by rapidly pressing the key button, another section of the monostable multivibrator prevents successive keying until a 1.2sec timeout period has elapsed.

The 74HC221 non-retriggerable monostable multivibrator is ideal for this function. Do not confuse this device with the 74HC123 retriggerable monostable multivibrator that has the same pin-out.

• Battery life

Battery life should be excellent as both the monostable and encoder are CMOS –neither draw measurable current when at rest. Limiting the transmission time also reduces battery load. As a result, the battery may never need replacement. The way the 74HC221 monostable works is that there is no voltage across the timing resistors when the device is at rest –without voltage, they cannot add load. Note that not all monostables work this way –some have significant standby current. Read more here.

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