參數(shù)資料
型號(hào): LM1872
廠商: National Semiconductor Corporation
英文描述: Radio Control Receiver/Decoder
中文描述: 遙控接收器/解碼器
文件頁(yè)數(shù): 18/19頁(yè)
文件大小: 371K
代理商: LM1872
Applications
(Continued)
BRIDGE DRIVING A MOTOR
The two digital channels can be used to propel a car for-
ward, off, and reverse without the need for a costly servo
(Figure 16). The 100 mA digital output capability is used to
drive a bridge of four transistors with Q5 added as a protec-
tion device. Should an erroneous command to power both
sides of the bridge occur (as may happen due to noise with
the car out of range) the large motor drive transistors would
fight one another resulting in the thermal destruction of one
or more of those devices. But Q5 will disable the left side of
the bridge whenever the right side is powered, preventing
the problem from ever occurring. The motor noise suppres-
sion network shown has proven to be especially effective in
reducing electrical noise and is therefore highly recom-
mended.
NOISE INTEGRATION OF A DIGITAL CHANNEL
Commonly available inexpensive DC motors are a formida-
ble source of electromagnetic interference. Radiation can
come from the power feed leads and/or directly from the
brushes. Usually proper lead dress and board orientation
coupled with a good filter network (see Figure 16 ) will elimi-
nate any problems. In particularly stubborn cases of motor
interference, the digital channels may experience more ob-
jectionable interference than the analog channels. This is
generally not because the digital channels are more suscep-
tible, but rather because the type of load they typically drive
(i.e. a horn) will make more of a nuisance of itself than a
typical analog load (i.e. a steering servo) when subjected to
interference.
Straightforward time integration of the digital channel out-
puts works very well with any type or degree of motor inter-
ference. The simple circuits of Figure 17 integrate over a
period of about three frames (70 ms) and have approximate-
ly equal delay either going off or coming on.
TL/H/7912–27
FIGURE 15. Interfacing Directly to Standard Hobby Servos
18
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM1872N 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Radio Control Receiver/Decoder
LM1872N/A+ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Remote-Control Receiver/Decoder
LM1872N/B+ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Remote-Control Receiver/Decoder
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LM1875_05 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:20W AUDIO POWER AMPLIFIER