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2011年12月23日星期五

Wireless transmitter module works Detailed

Wireless transmitter module works Detailed

DF data transmitter automatic doors module operating frequency is 315M, the use of SAW SAW resonator frequency stabilization, high frequency stability, when the ambient temperature
varies between -25 to +85 degrees, the frequency drift of only 3ppm / °. Particularly suitable for a collection of multiple wireless remote control and data
transmission systems. SAW resonator frequency stability after the crystal, and general LC oscillator frequency stability and consistency is poor, even with high-
quality fine-tuning automatic door capacitance, temperature changes and vibration is also difficult to ensure that no frequency has been tuned will shift.
DF transmitter module has not established a coding circuit, and an increase of a data modulation transistor Q1, this structure makes it easy and other fixed
coding circuit, rolling code circuitry and microcontroller interface, without having to consider coding circuit voltage and output The size of the signal amplitude
value. Such as integrated circuits with the PT2262 with other codes when connected directly to their data output pin to the first 17 data input of the DF can be.
DF data module with a wide operating voltage range 3 ~ 12V, when the voltage is essentially the same transmission frequency changes, and the transmitter module
supporting the receiver module can be stable without any adjustment to receive. When the transmitter voltage is 3V, open to the transmission distance of about 20 to 50
meters, less transmission power, when the voltage is 5V at about 100 to 200 meters, when the voltage is 9V about 300 to 500 meters when firing voltage is 12V, the
optimum operating voltage, and has good emission results, emission current 60 mA, open to 700 to 800 meters transmission distance, transmission power of 500 mW. When
the voltage is greater than l2V increased power consumption, effective radiated power is no longer significantly increased. The module is characterized by relatively
large transmission power, transmission distance is far more suitable to communicate under adverse conditions. The best selection of 25 cm long antenna wire, the best
long-distance transmission can be erected, because the transmission of radio signals received many factors, it is generally practical distance from the nominal only
20% or less, this point needs to consideration when developing attention.
DF data module using ASK modulation method to reduce power consumption when transmitting data signals to stop when the current drops to zero, the data signal
transmitter module with the DF input resistance or can be connected directly rather than using capacitive coupling, or DF transmitter module will not work. Data should
be close to the actual work of DF data module voltage to obtain higher modulation effect.
DF launch best vertical launch modules mounted on the edge of the motherboard, more than 5mm should be left around the device to the distribution parameters from
IMPACT. DF module transmission distance and signal frequency and amplitude modulation, transmitter voltage and battery capacity, transmitting antenna, receiver
sensitivity, sending and receiving environment. Generally the maximum emission from the open area about 800 meters, there are obstacles in the case, the distance will
be shortened, due to radio signal transmission in the refraction and reflection will form some of the dead and the unstable region, different transceiver environment
will be different transceiver distance.

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