參數(shù)資料
型號: ELM334SM
廠商: Electronic Theatre Controls, Inc.
英文描述: GARAGE DOORMAN
中文描述: 車庫看門人
文件頁數(shù): 4/4頁
文件大小: 29K
代理商: ELM334SM
Example Application
4 of 4
Figure 1 shows the ELM334 in a typical circuit that
provides both monitoring and control. An unregulated
12V supply is used to drive the relay coil and is stepped
down to 5V for the IC. The regulation isn’t essential for
this type of circuit, but it is a convenient means to
reduce the 12V, while providing some filtering from
motor noise, etc.
Operation of the LED portion of this circuit is
straight-forward. The position sensing magnetic reed
switches are connected to the 5.1K
pullup resistors in
order to provide a full logic swing input to the ELM334
as they operate. The 2.2K
series resistors provide
some protection for the chip as the wires to the switches
are likely to be lengthy, and susceptible to induced
voltages and currents. After processing, the appropriate
voltages appear at pins 2 and 3, driving the LEDs
through the 150
current limiting resistors.
The control portion of the circuit may appear to be a
little odd-looking at first. To understand its operation,
note that one of the two driven LEDs is always on,
whether flashing or solid. Due to the connection of the
two NPN transistors then, one of the NPNs is always
biased on, keeping the PNP on, and pin 4 of the
ELM334 at 5V. When the pushbutton is pressed, the
LED circuit is shorted out, and neither NPN can
conduct. The PNP thus shuts off, and pin 4 of the IC
drops to 0V, its active level. With the PB input active, a
high level is output at pin 5, causing the relay to pick up.
Although this circuit was designed for a very
specific purpose, there are likely to be many other
applications that it can be adapted to. Monitoring
thermostats perhaps, or water levels…
ELM334
ELM334DSB
< http://www.elmelectronics.com/ >
78L05
red
To the
motor
control
0.1μF
+12V
0.1μF
1
2
3
4
8
7
6
5
2.2K
2N3904
1N4001
+12V
12V Relay
green
‘closed’
‘open’
Remote LEDs
& Pushbutton Control
10K
2N3904
10K
2N3904
+5V
+5V
2.2K
2.2K
5.1K
5.1K
150
150
+5V
+5V
+5V
2N3906
10K
5.1K
5.1K
Figure 1. Typical Monitoring and Control Circuit
相關(guān)PDF資料
PDF描述
ELM337 LIGHT SWITCH
ELM337P LIGHT SWITCH
ELM337SM LIGHT SWITCH
ELM381 60 Hz Long Interval Counter
ELM413 LED controller and a circuit startup timer in an 8 pin package
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ELM3-350 制造商:BIVAR INC 功能描述:MISCELLANEOUS LED SPACER
ELM-3-360 制造商:Bivar 功能描述:
ELM33605GD 功能描述:LED 電路板指示器 Vert LED Assembly 5mm Green 565 nm RoHS:否 制造商:Lumex LED 大小:3 mm 照明顏色:Green 波長:565 nm 光強度:30 mcd 安裝類型:SMD/SMT 顯示角:60 deg 封裝:Reel
ELM33605YD 功能描述:LED 電路板指示器 Vert LED Assembly 5mm Yellow 585 nm RoHS:否 制造商:Lumex LED 大小:3 mm 照明顏色:Green 波長:565 nm 光強度:30 mcd 安裝類型:SMD/SMT 顯示角:60 deg 封裝:Reel
ELM337 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LIGHT SWITCH