Micro
Subway
Pass code entry chip MSP500
Introduction:
The
Pass Code Entry chip is a very low cost easy to use single chip solution. We do
all the work for you, simply connect a keypad and few external components and the
battery, you have built an advanced security element based on our single chip
pass code entry. It can’t be simpler than that!
This
low power pass code entry chip uses a keypad (0 to 9 plus * and #) to control
the entry into a protected zone or similar. The output is temporarily enabled
high by entering a 4 digits code followed by the # key. The 4 digits code can
easily be modified at any time. When the correct pass code is entered the
output goes high for few seconds allowing access into the restricted area or
performing a similar secured transaction. The output can be used to control the
drive of a solenoid, a dead bolt electric lock, a strike electric lock or
similar. A simple driver, if needed and depending on application, can be used
to provide the high power output drive. The output driver is used to enable the
MSP500 chip to drive the higher power load electric lock or similar. All low
power electronics need the higher power drivers to interface to higher power loads;
otherwise the high power loads will damage the low power electronics. Here is
the recommended simple connection for the MSP500 pass code entry chip and the
driver:
Figure
1.
The basic block diagram of the MSP500 security chip.
Operation:
The
security chip basic block is illustrated in figure 1 above. The keypad connects
to the chip along with the 5 VDC power supply. There are 12 keys that are used
to interact with the security chip. These keys are 0 to 9 and the * and # keys.
To access the secured item or area just press the # key followed by the 4 digit
security keys followed by the # key again. The Output pin goes high for two
seconds and goes back low. The chip will deny access if the wrong code (or
sequence of code digits) entered. The chip comes with an option in which you
can have audiovisual indicators to allow more friendly interaction. Please
contact us at micro@microsubway.com should
you need special or additional features. We will be more than happy to assist
you with all of your technical needs.
Uses:
People
have used this chip in applications such as authentication electronics to
access offices, unlock or lock their safe boxes, start or stop secured motors, secure
autos, experimentation, various projects, and other.
If
you are enabling or disabling a low power devices (for example 5 VDC at 20 mA
or less) then you don’t need a power driver, otherwise a simple power driver is
needed. For example if you need to activate an electric dead bolt lock (by
using the Output pin of the MSP500 security chip) operating at 12 or 24 volts
DC then a driver is needed since the MSP500 has a max output voltage of 5 volts
DC and 20 mA of current. In this case you may connect the Output pin of the
MSP500 chip to the Input of the transistor drive of figure 2 below. Points X
and Y of figure 2 below can handle power as per the ratings of the relay RLY1,
please refer to the power ratings of the relay you are using. You may use any
relay as long as you confirm to the power requirements of its primary coil connecting
to D1 diode and the secondary connecting to points X and Y.
Figure
2.
Connecting the MST1000 output to the high power transistor load driver.
Make
sure that the primary coil of the relay RLY1 you are using has power rating close
to the Vsupply DC voltage, to enable proper operation and safe ON-OFF
connection at the secondary of X and Y points. Be advised that this is not the
only configuration that can serve your purpose. Please contact us if you have
any technical request.
Unit
price:
1
to 10: $6.99
10
to 999: $5.99
1000+:
$3.99
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