ELECTRIC FIELD DISTURBANCE MONITOR (64) (static1) This schematic is the power supply and front-end sections of the field monitor that is discussed in more detail at Electric Field Disturbance Monitor. The system can detect human and animal motion by the electric fields they disturb. |
ELECTRIC FIELD DISTURBANCE MONITOR (65) (static2) This schematic is the motion discriminator alarm and battery monitor sections of the field monitor that is discussed in more detail a Electric Field Disturbance Monitor. (link is off-site) |
12C508 Smart Lock: The base sends a data sequence (the password) which is recognized by the key. The key checks the sequence and -if it recognizes it -sends to the base another data sequence, as an answer to the password. At the Time when the base gets a correct answer (which means that the key has been introduced), the relay is put into action, and it can command a number of consumers. |
Auto Burglar Alarm: This alarm circuit is based on two555 Timers. The alarm will sound your car horn if anyone opens the car door while the circuit is armed. The Timers will allow you to leave the car without sounding the horn. To turn the circuit on S1 must be closed. To set the alarm, open S2 ( it is normally closed ) this will give you about5 seconds to get out and close the door. The exit delay Time is set by R1 and C1. If anyone opens the doors for more then two seconds the horn will sound until power is removed from the circuit. The2 second Time is set by R2 and C2. If you open the door, you must deactivate the alarm by closing S2. This very basic circuit could be used for a home also. |
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 |
Cut Phone Line Detector #1: Can be used to alarm security system |
Door/window sensor resists tampering |
Oscillating output improves system security: Many electronic-control systems have digital outputs that use transistors. One method of improving the security in these outputs is to use an oscillating signal to represent a logic-high state instead of a fixed voltage level (Figure 1). This type of signal, a dynamic variable, can drive the circuit shown in Figure 2... |
Perimeter Monitor: Using a single cable such as speaker wire or doorbell cable, this circuit can be remotely positioned, for example, at the bottom of a garden or garage, and used to detect all sound in that area. The cable can be buried in a hosepipe or duct and is concealed out of sight. The mic is an ordinary dynamic mic insert and should be housed in a waterproof enclosure with the rest of the circuit. |
Simple Electronic Lock Uses Single-Transistor Circuit: |
Single Button Lock Provides High Security: PDF contains multiple circuits - scroll to find this circuit. |
