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12C508 Smart Lock: base sends a data sequence ( password) which is recognized by key. key checks
sequence and -if it recognizes it -sends to base anor data sequence, as an answer to password. At Time when base gets a correct answer (which means that key has
been introduced), relay is put into action, and it can command a number of consumers. (added 4/02) |
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4 Digit Keypad: (circuit design added 8/03) |
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5 Zone Alarm Circuit: (design circuit added 8/02) |
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6A door lock motor driver for automotive: AN456AN456AN456AN456AN456 nal (OVV), put at low level enable of
L9937, confirming hardware switch-off of motor ; in this condition an output of half bridge is in... (app note added 6/06) |
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Alarm Control keypad: (circuit design added 8/03) |
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Almost Ultrasonic Motion Sensor: (circuit design added 8/03) |
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Analog Video Router: Intersil Application Block Diagram (app note added 6/06) |
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Anti Theft Motorcycle Alarm: (electronic design added 9/02) |
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Anti-Bag-Snatching Alarm: (electronic Circuit / Schematic added 10/04) |
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Anti-Theft Alarm for Bikes: (electronic Circuit / Schematic added 10/04) |
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Anti-Theft Security for Car Audios: (electronic Circuit / Schematic added 10/04) |
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Automatic door opener with PIC12C508: This circuit can be used to operate an electric strike or an electromagnetic lock on
a door. It is not door being opened/closed, but a small electromagnetic strike which unlocks door…. (added 4/05) |
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Basic RF Transmitter for PIR Sensors: (circuit design added 8/03) |
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Combination Lock: This circuit is very basic to build. To open a the lock which is connected to the K1 Load. you must press
each momentary switch in the correct sequence. The sequence used in this circuit is S1,S2,S3,S4. If any of the other switches are pressed the circuit will reset and you will need to start
over. Depending on how you wire the switches, you can use any4 switch combination (added 2/03) |
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Combination Lock (PIC16F84): (circuit design added 8/03) |
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Cut Phone Line Detector #1: Can be used to alarm security system (added 4/02) |
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Digital Combination Lock: (electronic design added 9/02) |
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Digital Electronic Lock: (electronic (schematic / circuit added 11/05) |
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Door/Window Sensor Resists Tampering: 01/21/99 EDN-Design Ideas / (added 11/05) The simple, inexpensive circuit in
Figure 1 detects a failure (or deliberate tampering) on lines connected to normally closed switch sensors. For example, common door interlocks and door/window sensors consist of normally open
or normally closed magnetic reed switches. Depending on the monitoring configuration, an open or short on a line may go undetected, thus preventing alarm activation. Embedding a resistor in a
normally closed sensor and using bipolar dc power supplies produces the balanced configuration in Figure 1. A short or open on a line (or sensor activation) produces a net positive or negative
voltage at the input of the Q1-Q2 pair.... |